Self-dual Yang-Mills fields in an Einstein universe
Pavlov, A. )
1992-12-01
Instanton solutions of Yang-Mills fields in flat Euclidean space have importance in studying the guage field vacuum. The authors find exact solutions of the self-consistent Einstein-Yang-Mills system of equations. These solutions are self-dual Yang-Mills fields in I[sup 1] [times] S[sup 3] space-time. The self-dual solutions have trivial topology and do not belong to instatons. The results of this study may help in understanding the vacuum structure of the fields under consideration. 4 refs.
Self-dual electromagnetic fields
NASA Astrophysics Data System (ADS)
Chubykalo, Andrew E.; Espinoza, Augusto; Kosyakov, B. P.
2010-08-01
We demonstrate the utility of self-dual fields in electrodynamics. Stable configurations of free electromagnetic fields can be represented as superpositions of standing waves, each possessing zero Poynting vector and zero orbital angular momentum. The standing waves are themselves superpositions of self-dual and anti-self-dual solutions. The idea of self-duality provides additional insights into the geometrical and spectral properties of stable electromagnetic configurations, such as those responsible for the formation of ball lightning.
Gravitational waves as deformations of embedded Einstein spaces
NASA Astrophysics Data System (ADS)
Kerner, Richard; Vitale, Salvatore
2009-12-01
We show how approximate radiative solutions of Einstein's equations can be constructed using small deformations of Einstein spacetimes embedded into a pseudo-Euclidean flat space of higher dimension. Infinitesimal deformations are seen then as vector fields in EN. All geometrical quantities can be then expressed in terms of embedding functions zA and their deformations v^A, z^A \\rightarrow {\\tilde{z}}^A = z^A + \\varepsilon \\, v^A + \\varepsilon ^2 \\, w^A +\\cdots . Then we require the deformations to keep Einstein equations satisfied up to a given order in ɛ. The system obtained is then analyzed in particular cases of the Minkowski and Schwarzschild manifolds taken as a starting point, and solutions of deformations of Einstein's equations displaying radiative behavior are found up to the third order of expansion in small parameter ɛ.
Einstein-Weyl spaces and third-order differential equations
NASA Astrophysics Data System (ADS)
Tod, K. P.
2000-08-01
The three-dimensional null-surface formalism of Tanimoto [M. Tanimoto, "On the null surface formalism," Report No. gr-qc/9703003 (1997)] and Forni et al. [Forni et al., "Null surfaces formation in 3D," J. Math Phys. (submitted)] are extended to describe Einstein-Weyl spaces, following Cartan [E. Cartan, "Les espaces généralisées et l'integration de certaines classes d'equations différentielles," C. R. Acad. Sci. 206, 1425-1429 (1938); "La geometria de las ecuaciones diferenciales de tercer order," Rev. Mat. Hispano-Am. 4, 1-31 (1941)]. In the resulting formalism, Einstein-Weyl spaces are obtained from a particular class of third-order differential equations. Some examples of the construction which include some new Einstein-Weyl spaces are given.
Space-time curvature signatures in Bose-Einstein condensates
NASA Astrophysics Data System (ADS)
Matos, Tonatiuh; Gomez, Eduardo
2015-05-01
We derive a generalized Gross-Pitaevski (GP) equation for a Bose Einstein Condensate (BEC) immersed in a weak gravitational field starting from the covariant Complex Klein-Gordon field in a curved space-time. We compare it with the traditional GP equation where the gravitational field is added by hand as an external potential. We show that there is a small difference of order gz/c2 between them that could be measured in the future using Bose-Einstein Condensates. This represents the next order correction to the Newtonian gravity in a curved space-time.
Separate Einstein-Eddington Spaces and the Cosmological Constant
NASA Astrophysics Data System (ADS)
Azri, Hemza
2016-07-01
In affine variational principle, a symmetric linear connection is taken as a fundamental field. The metric tensor is generated dynamically, and it appears as a canonically conjugate to the connection. From this picture, Einstein's gravity with a cosmological constant can be obtained by a covariant Legendre transformation of the affine Lagrangian. In this talk, we apply this formalism (first proposed by Kijowski) to product spaces and the cosmological constant problem. From pure affine variational principle, we derive the separate Einstein space described by its Ricci tensor. The derived equations spite into two field equations of motion that describe two maximally symmetric spaces with two non independent cosmological constants. We propose that the invariance of the bi-field equations under projections on the separate spaces, may render one of the cosmological constants to zero. We also formulate the model in the presence of matter fields. The resulted separate Einstein-Eddington spaces maybe considered as two states that describe the universe before and after inflation. A possibly interesting affine action for a general perfect fluid is also proposed. It turns out that the condition which leads to zero cosmological constant in the vacuum case, eliminates here the effects of the gravitational mass density of the perfect fluid, and the dynamic of the universe in its final state is governed by only the inertial mass density of the fluid. We present no new solutions to the problems associated with inflation.
Non-existence of dynamical perturbations of Schwarzschild with vanishing self-dual part
NASA Technical Reports Server (NTRS)
Wald, R. M.
1986-01-01
A recent proposal of Ashtekar (1985) for the canonical quantisation of gravity involves a new choice of a (complex) polarisation on the (real) phase space of general relativity. In order for the 'four dimensional' version of Ashtekar's proposal to be viable, it is necessary that for an arbitrary (real) background solution there exist a sufficient number of (complex) solutions of the linearised Einstein equation with perturbed Weyl spinor having vanishing self-dual part. It is shown that this is not the case by explicitly demonstrating that for the Schwarzschild spacetime, aside from stationary perturbations, there are no such linearised solutions which can be expressed as superpositions of modes of real frequencies. The viability of the '3+1 version' of Ashtekar's proposal is not affected by these considerations.
Einstein's Symphony: A Gravitational Wave Voyage Through Space and Time
NASA Astrophysics Data System (ADS)
Shapiro Key, Joey; Yunes, Nico; Grimberg, Irene
2015-01-01
Einstein's Symphony: A Gravitational Wave Voyage Through Space and Time is a gravitational wave astronomy planetarium show in production by a collaboration of scientists, filmmakers, and artisits from the Center for Gravitational Wave Astonomy (CGWA) at the University of Texas at Brownsville (UTB) and Montana State University (MSU). The project builds on the success of the interdisciplinary Celebrating Einstein collaboration. The artists and scientists who created the A Shout Across Time original film and the Black (W)hole immersive art installation for Celebrating Einstein are teaming with the Museum of the Rockies Taylor Planetarium staff and students to create a new full dome Digistar planetarium show that will be freely and widely distributed to planetaria in the US and abroad. The show uses images and animations filmed and collected for A Shout Across Time and for Black (W)hole as well as new images and animations and a new soundtrack composed and produced by the MSU School of Music to use the full capability of planetarium sound systems. The planetarium show will be narrated with ideas drawn from the Celebrating Einstein danced lecture on gravitational waves that the collaboration produced. The combination of products, resources, and team members assembled for this project allows us to create an original planetarium show for a fraction of the cost of a typical show. In addition, STEM education materials for G6-12 students and teachers will be provided to complement and support the show. This project is supported by the Texas Space Grant Consortium (TSGC), Montana Space Grant Consortium (MSGC), and the American Physical Society (APS).
Self-dual geometry of generalized Hermitian surfaces
Arsen'eva, O E; Kirichenko, V F
1998-02-28
Several results on the geometry of conformally semiflat Hermitian surfaces of both classical and hyperbolic types (generalized Hermitian surfaces) are obtained. Some of these results are generalizations and clarifications of already known results in this direction due to Koda, Itoh, and other authors. They reveal some unexpected beautiful connections between such classical characteristics of conformally semiflat (generalized) Hermitian surfaces as the Einstein property, the constancy of the holomorphic sectional curvature, and so on. A complete classification of compact self-dual Hermitian RK-surfaces that are at the same time generalized Hopf manifolds is obtained. This provides a complete solution of the Chen problem in this class of Hermitian surfaces.
Alternative self-dual gravity in eight dimensions
NASA Astrophysics Data System (ADS)
Nieto, J. A.
2016-07-01
We develop an alternative Ashtekar formalism in eight dimensions. In fact, using a MacDowell-Mansouri physical framework and a self-dual curvature symmetry, we propose an action in eight dimensions in which the Levi-Civita tenor with eight indices plays a key role. We explicitly show that such an action contains number of linear, quadratic and cubic terms in the Riemann tensor, Ricci tensor and scalar curvature. In particular, the linear term is reduced to the Einstein-Hilbert action with cosmological constant in eight dimensions. We prove that such a reduced action is equivalent to the Lovelock action in eight dimensions.
NASA Astrophysics Data System (ADS)
Chapline, George
It has been shown that a nonlinear Schrödinger equation in 2+1 dimensions equipped with an SU(N) Chern-Simons gauge field can provide an exact description of certain self-dual Einstein spaces in the limit N-=∞. Ricci flat Einstein spaces can then be viewed as arising from a quantum pairing of the classical self-dual and anti-self-dual solutions. In this chapter, we will outline how this theory of empty space-time might be generalized to include matter and vacuum energy by transplanting the nonlinear Schrödinger equation used to construct Einstein spaces to the 25+1-dimensional Lorentzian Leech lattice. If the distinguished 2 spatial dimensions underlying the construction of Einstein spaces are identified with a hexagonal lattice section of the Leech lattice, the wave-function becomes an 11 × 11 matrix that can represent fermion and boson degrees of freedom (DOF) associated with 2-form and Yang-Mills gauge symmetries. The resulting theory of gravity and matter in 3+1 dimensions is not supersymmetric, which provides an entry for a vacuum energy. Indeed, in the case of a Lemaitre cosmological model, the emergent space-time will naturally have a vacuum energy on the order of the observed cosmological constant.
Multimatrix models and tri-Sasaki Einstein spaces
Herzog, Christopher P.; Pufu, Silviu S.; Tesileanu, Tiberiu; Klebanov, Igor R.
2011-02-15
Localization methods reduce the path integrals in N{>=}2 supersymmetric Chern-Simons gauge theories on S{sup 3} to multimatrix integrals. A recent evaluation of such a two-matrix integral for the N=6 superconformal U(N)xU(N) Aharony-Bergman-Jafferis-Maldacena theory produced detailed agreement with the AdS/CFT correspondence, explaining, in particular, the N{sup 3/2} scaling of the free energy. We study a class of p-matrix integrals describing N=3 superconformal U(N){sup p} Chern-Simons gauge theories. We present a simple method that allows us to evaluate the eigenvalue densities and the free energies in the large N limit keeping the Chern-Simons levels k{sub i} fixed. The dual M-theory backgrounds are AdS{sub 4}xY, where Y are seven-dimensional tri-Sasaki Einstein spaces specified by the k{sub i}. The gravitational free energy scales inversely with the square root of the volume of Y. We find a general formula for the p-matrix free energies that agrees with the available results for volumes of the tri-Sasaki Einstein spaces Y, thus providing a thorough test of the corresponding AdS{sub 4}/CFT{sub 3} dualities. This formula is consistent with the Seiberg duality conjectured for Chern-Simons gauge theories.
Stationary axisymmetric four dimensional space-time endowed with Einstein metric
Hasanuddin; Azwar, A.; Gunara, B. E.
2015-04-16
In this paper, we construct Ernst equation from vacuum Einstein field equation for both zero and non-zero cosmological constant. In particular, we consider the case where the space-time admits axisymmetric using Boyer-Lindquist coordinates. This is called Kerr-Einstein solution describing a spinning black hole. Finally, we give a short discussion about the dynamics of photons on Kerr-Einstein space-time.
Loop quantum cosmology with self-dual variables
NASA Astrophysics Data System (ADS)
Wilson-Ewing, Edward
2015-12-01
Using the complex-valued self-dual connection variables, the loop quantum cosmology of a closed Friedmann space-time coupled to a massless scalar field is studied. It is shown how the reality conditions can be imposed in the quantum theory by choosing a particular inner product for the kinematical Hilbert space. While holonomies of the self-dual Ashtekar connection are not well defined in the kinematical Hilbert space, it is possible to introduce a family of generalized holonomylike operators of which some are well defined; these operators in turn are used in the definition of the Hamiltonian constraint operator where the scalar field can be used as a relational clock. The resulting quantum theory is closely related, although not identical, to standard loop quantum cosmology constructed from the Ashtekar-Barbero variables with a real Immirzi parameter. Effective Friedmann equations are derived which provide a good approximation to the full quantum dynamics for sharply peaked states whose volume remains much larger than the Planck volume, and they show that for these states quantum gravity effects resolve the big-bang and big-crunch singularities and replace them by a nonsingular bounce. Finally, the loop quantization in self-dual variables of a flat Friedmann space-time is recovered in the limit of zero spatial curvature and is identical to the standard loop quantization in terms of the real-valued Ashtekar-Barbero variables.
Projective equivalence of Einstein spaces in general relativity
NASA Astrophysics Data System (ADS)
Hall, G. S.; Lonie, D. P.
2009-06-01
There has been some recent interest in the relation between two spacetimes which have the same geodesic paths, that is, spacetimes which are projectively equivalent (sometimes called geodesically equivalent). This paper presents a short and accessible proof of the theorem that if two spacetimes have the same geodesic paths and one of them is an Einstein space then (either each is of constant curvature or) their Lévi-Civitá connections are identical. It also clarifies the relationship between their associated metrics. The results are extended to include the signatures (+ + + +) and (- - + +), and some examples and discussion are given in the case of dimension n > 4. Some remarks are also made which show how these results may be useful in the study of projective symmetry.
Momentum-space engineering of gaseous Bose-Einstein condensates
Edwards, Mark; Benton, Brandon; Heward, Jeffrey; Clark, Charles W.
2010-12-15
We show how the momentum distribution of gaseous Bose-Einstein condensates can be shaped by applying a sequence of standing-wave laser pulses. We present a theory, whose validity was demonstrated in an earlier experiment [L. Deng et al., Phys. Rev. Lett. 83, 5407 (1999)], of the effect of a two-pulse sequence on the condensate wavefunction in momentum space. We generalize the previous result to the case of N pulses of arbitrary intensity separated by arbitrary intervals and show how these parameters can be engineered to produce a desired final momentum distribution. We find that several momentum distributions, important in atom-interferometry applications, can be engineered with high fidelity with two or three pulses.
On the Theory of Geodesic Mappings of Einstein Spaces and their Generalizations
NASA Astrophysics Data System (ADS)
Mikeš, Josef; Hinterleitner, Irena; Kiosak, Vladimir A.
2006-11-01
In this paper we consider results of the theory of geodesic mappings of Einstein spaces and their generalizations. In 1925 H. Brinkmann found the metric of equidistant spaces and obtained conditions, when these spaces are Einstein spaces, resp. spaces of constant curvature. We introduce the conditions on these spaces when they are semisymmetric, pseudosymmetric, Ricci semisymmetric, Ricci pseudosymmetric and spaces Vn(B). A diffeomorphism f between Riemannian spaces Vn and V¯n is called a geodesic mapping, if any geodesic line in Vn is mapped into a geodesic line in V¯n. In 1954 N.S. Sinyukov proved that equidistant spaces admit geodesic mappings. Our constructions of a geodesic mapping of Einstein spaces with the Brinkmann metric proves that Petrov's conjecture is not true. We formulate results by E. Beltrami, R. Couty, V.I. Golikov, S. Formella, V.A. Kiosak, T. Levi-Civita, J. Mikeš, A.Z. Petrov and A.V. Pogorelov about geodesic mappings of Einstein spaces and spaces of constant curvature. Further we introduce results on geodesic mappings for Riemannian spaces, which are generalized Einstein spaces and spaces of constant curvature. For instance symmetric, recurrent, generalized recurrent, semisymmetric, pseudosymmetric, Ricci semisymmetric, Ricci pseudosymmetric spaces, spaces with harmonic curvature, etc. These results were obtained by many authors: R. Deszcz, V.A. Kiosak, J. Mikeš, N.S. Sinykov, E.N. Sinyukova, V.S. Sobchuk, etc.
Quantum billiards with branes on product of Einstein spaces
NASA Astrophysics Data System (ADS)
Ivashchuk, V. D.
2016-05-01
We consider a gravitational model in dimension D with several forms, l scalar fields and a Λ -term. We study cosmological-type block-diagonal metrics defined on a product of an 1-dimensional interval and n oriented Einstein spaces. As an electromagnetic composite brane ansatz is adopted and certain restrictions on the branes are imposed the conformally covariant Wheeler-DeWitt (WDW) equation for the model is studied. Under certain restrictions, asymptotic solutions to the WDW equation are found in the limit of the formation of the billiard walls. These solutions reduce the problem to the so-called quantum billiard in (n + l -1)-dimensional hyperbolic space. Several examples of quantum billiards in the model with electric and magnetic branes, e.g. corresponding to hyperbolic Kac-Moody algebras, are considered. In the case n=2 we find a set of basis asymptotic solutions to the WDW equation and derive asymptotic solutions for the metric in the classical case.
Saving Space and Time: The Tractor That Einstein Built
NASA Technical Reports Server (NTRS)
2006-01-01
In 1984, NASA initiated the Gravity Probe B (GP-B) program to test two unverified predictions of Albert Einstein s theory of general relativity, hypotheses about the ways space, time, light, and gravity relate to each other. To test these predictions, the Space Agency and researchers at Stanford University developed an experiment that would check, with extreme precision, tiny changes in the spin direction of four gyroscopes contained in an Earth satellite orbiting at a 400-mile altitude directly over the Earth s poles. When the program first began, the researchers assessed using Global Positioning System (GPS) technology to control the attitude of the GP-B spacecraft accurately. At that time, the best GPS receivers could only provide accuracy to nearly 1 meter, but the GP-B spacecraft required a system 100 times more accurate. To address this concern, researchers at Stanford designed high-performance, attitude-determining hardware that used GPS signals, perfecting a high-precision form of GPS called Carrier-Phase Differential GPS that could provide continuous real-time position, velocity, time, and attitude sensor information for all axes of a vehicle. The researchers came to the realization that controlling the GP-B spacecraft with this new system was essentially no different than controlling an airplane. Their thinking took a new direction: If this technology proved successful, the airlines and the Federal Aviation Administration (FAA) were ready commercial markets. They set out to test the new technology, the "Integrity Beacon Landing System," using it to automatically land a commercial Boeing 737 over 100 times successfully through Real-Time Kinematic (RTK) GPS technology. The thinking of the researchers shifted again, from automatically landing aircraft, to automating precision farming and construction equipment.
NASA Astrophysics Data System (ADS)
Lake, Kayll
2010-12-01
The title immediately brings to mind a standard reference of almost the same title [1]. The authors are quick to point out the relationship between these two works: they are complementary. The purpose of this work is to explain what is known about a selection of exact solutions. As the authors state, it is often much easier to find a new solution of Einstein's equations than it is to understand it. Even at first glance it is very clear that great effort went into the production of this reference. The book is replete with beautifully detailed diagrams that reflect deep geometric intuition. In many parts of the text there are detailed calculations that are not readily available elsewhere. The book begins with a review of basic tools that allows the authors to set the notation. Then follows a discussion of Minkowski space with an emphasis on the conformal structure and applications such as simple cosmic strings. The next two chapters give an in-depth review of de Sitter space and then anti-de Sitter space. Both chapters contain a remarkable collection of useful diagrams. The standard model in cosmology these days is the ICDM model and whereas the chapter on the Friedmann-Lemaître-Robertson-Walker space-times contains much useful information, I found the discussion of the currently popular a representation rather too brief. After a brief but interesting excursion into electrovacuum, the authors consider the Schwarzschild space-time. This chapter does mention the Swiss cheese model but the discussion is too brief and certainly dated. Space-times related to Schwarzschild are covered in some detail and include not only the addition of charge and the cosmological constant but also the addition of radiation (the Vaidya solution). Just prior to a discussion of the Kerr space-time, static axially symmetric space-times are reviewed. Here one can find a very interesting discussion of the Curzon-Chazy space-time. The chapter on rotating black holes is rather brief and, for
Killing–Yano tensor and supersymmetry of the self-dual Plebański–Demiański solution
NASA Astrophysics Data System (ADS)
Nozawa, Masato; Houri, Tsuyoshi
2016-06-01
We explore various aspects of the self-dual Plebański–Demiański (PD) family in the Euclidean Einstein–Maxwell-Λ system. The Killing–Yano tensor which was recently found by Yasui and one of the present authors allows us to prove that the self-dual PD metric can be brought into the self-dual Carter metric by an orientation-reversing coordinate transformation. We show that the self-dual PD solution admits two independent Killing spinors in the framework of N = 2 minimal gauged supergravity, whereas the non-self-dual solution admits only a single Killing spinor. This can be demonstrated by casting the self-dual PD metric into two distinct Przanowski–Tod forms. As a by-product, a new example of the three-dimensional Einstein–Weyl space is presented. We also prove that the self-dual PD metric falls into two different Calderbank–Pedersen families, which are determined by a single function subjected to a linear equation on the two-dimensional hyperbolic space. Furthermore, we consider the hyper-Kähler case for which the metric falls into the Gibbons–Hawking class. We find that the condition for the nonexistence of the Dirac–Misner string enforces the solution with a nonvanishing acceleration parameter to the Eguchi–Hanson space.
Complete integrability of geodesic motion in Sasaki-Einstein toric Yp,q spaces
NASA Astrophysics Data System (ADS)
Babalic, Elena Mirela; Visinescu, Mihai
2015-09-01
We construct explicitly the constants of motion for geodesics in the five-dimensional Sasaki-Einstein spaces Yp,q. To carry out this task, we use the knowledge of the complete set of Killing vectors and Killing-Yano tensors on these spaces. In spite of the fact that we generate a multitude of constants of motion, only five of them are functionally independent implying the complete integrability of geodesic flow on Yp,q spaces. In the particular case of the homogeneous Sasaki-Einstein manifold T1,1 the integrals of motion have simpler forms and the relations between them are described in detail.
Non-self-dual static gauge fields
NASA Astrophysics Data System (ADS)
Oh, C. H.; Teh, Rosy
1980-01-01
We exhibit exact non-self-dual static solutions to the SU(2) Yang-Mills field equations by solving the equation ∇2V+λV3=0 using cylindrical and spherical coordinates. The resulting gauge fields are complex and have singularities. For the cylindrically symmetric solution, we convert it into a real gauge field coupled to the Higgs field in the limit in which the self-interaction potential of the Higgs field vanishes.
Bogoliubov space of a Bose-Einstein condensate and quantum spacetime fluctuations
Rivas, J. I.; Camacho, A.; Goeklue, E.
2012-08-24
We analyze the role that metric fluctuations could have on the features of a Bose-Einstein condensate. Particularly, the Bogoliubov space associated to it is considered and it will be shown that the pressure and the speed of sound of the ground state define an expression allowing us to determine the average size of these fluctuations.
Anisotropic loop quantum cosmology with self-dual variables
NASA Astrophysics Data System (ADS)
Wilson-Ewing, Edward
2016-04-01
A loop quantization of the diagonal class A Bianchi models starting from the complex-valued self-dual connection variables is presented in this paper. The basic operators in the quantum theory correspond to areas and generalized holonomies of the Ashtekar connection, and the reality conditions are implemented via the choice of the inner product on the kinematical Hilbert space. The action of the Hamiltonian constraint operator is given explicitly for the case when the matter content is a massless scalar field (in which case the scalar field can be used as a relational clock), and it is shown that the big bang and big crunch singularities are resolved in the sense that singular and nonsingular states decouple under the action of the Hamiltonian constraint operator.
Self-dual gravity and self-dual Yang-Mills theory in the context of the Macdowell-Mansouri formalism
NASA Astrophysics Data System (ADS)
Nieto, J. A.; Socorro, J.
1999-02-01
In this work we propose an action which unifies self-dual gravity and self-dual Yang-Mills theory in the context of the Macdowell-Mansouri formalism. We claim that such an action may be used to find the S-dual action for both self-dual gravity and self-dual Yang-Mills theory.
The LISA Pathfinder Mission. Tracing Einstein's Geodesics in Space
NASA Astrophysics Data System (ADS)
Racca, Giuseppe D.; McNamara, Paul W.
2010-03-01
LISA Pathfinder, formerly known as SMART-2, is the second of the European Space Agency’s Small Missions for Advance Research and Technology, and is designed to pave the way for the joint ESA/NASA Laser Interferometer Space Antenna (LISA) mission, by testing the core assumption of gravitational wave detection and general relativity: that free particles follow geodesics. The new technologies to be demonstrated in a space environment include: inertial sensors, high precision laser interferometry to free floating mirrors, and micro-Newton proportional thrusters. LISA Pathfinder will be launched on a dedicated launch vehicle in late 2011 into a low Earth orbit. By a transfer trajectory, the sciencecraft will enter its final orbit around the first Sun-Earth Lagrange point. First science results are expected approximately 3 months thereafter. Here, we give an overview of the mission including the technologies being demonstrated.
Magnon Kinetics and Bose-Einstein Condensation Studied in Phase Space
Demidov, V. E.; Dzyapko, O.; Buchmeier, M.; Demokritov, S. O.; Stockhoff, T.; Schmitz, G.; Melkov, G. A.
2008-12-19
Using a novel technique providing simultaneous resolution with respect to the wave vector and frequency of magnons, we observed the formation of a Bose-Einstein condensate documented by the narrowing of the magnon distribution in phase space. Based on the measured width of the distribution we determined the effective correlation length of the condensate, which appears to be anisotropic, reflecting the anisotropy of the magnon dispersion spectrum.
Zero modes of the self-dual Maxwell Chern-Simons solitons
Lee, C. ); Min, H. ); Rim, C. )
1991-06-15
We derive an explicit formula for the index of coupled Dirac-Klein-Gordon-type operators involving as background fields the scalar and vector fields of Higgs models in two space dimensions. The result is used to count the parameters entering the general static soliton solutions of recently found self-dual Maxwell Chern-Simons systems. We also discuss this finding on the basis of a more explicit representation of the general solution.
Theory of quantum gravity beyond Einstein and space-time dynamics with quantum inflation
NASA Astrophysics Data System (ADS)
Wu, Yue-Liang
2015-10-01
In this talk, I present a theory of quantum gravity beyond Einstein. The theory is established based on spinnic and scaling gauge symmetries by treating the gravitational force on the same footing as the electroweak and strong forces. A bi-frame space-time is initiated to describe the laws of nature. One frame space-time is a globally flat coordinate Minkowski space-time that acts as an inertial reference frame for the motions of fields, the other is a locally flat non-coordinate Gravifield space-time that functions as an interaction representation frame for the degrees of freedom of fields. The Gravifield is sided on both the globally flat coordinate space-time and locally flat non-coordinate space-time and characterizes the gravitational force. Instead of the principle of general coordinate invariance in Einstein theory of general relativity, some underlying principles with the postulates of coordinate independence and gauge invariance are motivated to establish the theory of quantum gravity. When transmuting the Gravifield basis into the coordinate basis in Minkowski space-time, it enables us to obtain equations of motion for all quantum fields and derive basic conservation laws for all symmetries. The gravity equation is found to be governed by the total energy-momentum tensor defined in the flat Minkowski space-time. When the spinnic and scaling gauge symmetries are broken down to a background structure that possesses the global Lorentz and scaling symmetries, we arrive at a Lorentz invariant and conformally flat background Gravifield space-time that is characterized by a cosmic vector with a non-zero cosmological mass scale. We also obtain the massless graviton and massive spinnon. The resulting universe is in general not isotropic in terms of conformal proper time and turns out to be inflationary in light of cosmic proper time. The conformal size of the universe has a singular at the cosmological horizon to which the cosmic proper time must be infinitely
100 years of relativity. Space-time structure: Einstein and beyond
NASA Astrophysics Data System (ADS)
Ashtekar, Abhay
2005-11-01
Thanks to Einstein's relativity theories, our notions of space and time underwent profound revisions about a 100 years ago. The resulting interplay between geometry and physics has dominated all of fundamental physics since then. This volume contains contributions from leading researchers, worldwide, who have thought deeply about the nature and consequences of this interplay. The articles take a long-range view of the subject and distill the most important advances in broad terms, making them easily accessible to non-specialists. The first part is devoted to a summary of how relativity theories were born (J. Stachel). The second part discusses the most dramatic ramifications of general relativity, such as black holes (P. Chrusciel and R. Price), space-time singularities (H. Nicolai and A. Rendall), gravitational waves (P. Laguna and P. Saulson), the large scale structure of the cosmos (T. Padmanabhan); experimental status of this theory (C. Will) as well as its practical application to the GPS system (N. Ashby). The last part looks beyond Einstein and provides glimpses into what is in store for us in the 21st century. Contributions here include summaries of radical changes in the notions of space and time that are emerging from quantum field theory in curved space-times (Ford), string theory (T. Banks), loop quantum gravity (A. Ashtekar), quantum cosmology (M. Bojowald), discrete approaches (Dowker, Gambini and Pullin) and twistor theory (R Penrose).
Einstein--Weyl space-times with geodesic and shear-free neutrino rays: asymptotic behaviour
Kolassis, C.A.; Santos, N.O.
1987-02-15
We consider a neutrino field with geodesic and shear-free rays, in interaction with a gravitational field according to the Einstein--Weyl field equations. Furthermore we suppose that there exists a Killing vector r/sup ..mu../ whose magnitude is almost everywhere bounded at the future and past endpoints of the neutrino rays. The implications of the asymptotic behavior of r/sup ..mu../ on the structure of space-time are investigated and a useful set of reduced equations is obtained. It is found that under these hypothes the space-time cannot be asymptotically flat if the neutrino field is nonvanishing. All the Demianski--Kerr--NUT-like space-times as well as the space-times which admit a covariantly constant null vector are explicity obtained. copyright 1987 Academic Press, Inc.
Plebanski-like action for general relativity and anti-self-dual gravity
NASA Astrophysics Data System (ADS)
Celada, Mariano; González, Diego; Montesinos, Merced
2016-05-01
We present a new B F -type action for complex general relativity with or without a cosmological constant resembling Plebanski's action, which depends on an SO (3 ,C ) connection, a set of 2-forms, a symmetric matrix, and a 4-form. However, it differs from the Plebanski formulation in the way that the symmetric matrix enters into the action. The advantage of this fact is twofold. First, as compared to Plebanski's action, the symmetric matrix can now be integrated out, which leads to a pure B F -type action principle for general relativity; the canonical analysis of the new action then shows that it has the same phase space of the Ashtekar formalism up to a canonical transformation induced by a topological term. Second, a particular choice of the parameters involved in the formulation produces a B F -type action principle describing conformally anti-self-dual gravity. Therefore, the new action unifies both general relativity and anti-self-dual gravity.
NASA Astrophysics Data System (ADS)
Shapiro Key, Joey; Yunes, Nicolas
2013-04-01
The Gravity Group at Montana State University (MSU) hosted Celebrating Einstein, a free public arts and multimedia event celebrating Einstein and his ideas in Bozeman, Montana April 2-6, 2013. The products of our efforts are now available to any party interested in hosting a similar event. Celebrating Einstein is a truly interdisciplinary effort including art, film, dance, music, physics, history, and education. Events included a black hole immersive art installation, a series of public talks by physicists, and Einstein lessons in the public schools leading up to a live free public multimedia performance including a professional dance company, a live interview with a renowned physicist, and an original score composed for the MSU student symphony to be performed with an original film produced by the Science and Natural History film program at MSU. This project is funded by the Montana Space Grant Consortium, Montana State University, and the National Science Foundation.
Quantum tests of the Einstein Equivalence Principle with the STE-QUEST space mission
NASA Astrophysics Data System (ADS)
Altschul, Brett; Bailey, Quentin G.; Blanchet, Luc; Bongs, Kai; Bouyer, Philippe; Cacciapuoti, Luigi; Capozziello, Salvatore; Gaaloul, Naceur; Giulini, Domenico; Hartwig, Jonas; Iess, Luciano; Jetzer, Philippe; Landragin, Arnaud; Rasel, Ernst; Reynaud, Serge; Schiller, Stephan; Schubert, Christian; Sorrentino, Fiodor; Sterr, Uwe; Tasson, Jay D.; Tino, Guglielmo M.; Tuckey, Philip; Wolf, Peter
2015-01-01
We present in detail the scientific objectives in fundamental physics of the Space-Time Explorer and QUantum Equivalence Space Test (STE-QUEST) space mission. STE-QUEST was pre-selected by the European Space Agency together with four other missions for the cosmic vision M3 launch opportunity planned around 2024. It carries out tests of different aspects of the Einstein Equivalence Principle using atomic clocks, matter wave interferometry and long distance time/frequency links, providing fascinating science at the interface between quantum mechanics and gravitation that cannot be achieved, at that level of precision, in ground experiments. We especially emphasize the specific strong interest of performing Equivalence Principle tests in the quantum regime, i.e. using quantum atomic wave interferometry. Although STE-QUEST was finally not selected in early 2014 because of budgetary and technological reasons, its science case was very highly rated. Our aim is to expose that science to a large audience in order to allow future projects and proposals to take advantage of the STE-QUEST experience.
Quantum phase-space picture of Bose-Einstein condensates in a double well
Mahmud, Khan W.; Perry, Heidi; Reinhardt, William P.
2005-02-01
We present a quantum phase-space model of the Bose-Einstein condensate (BEC) in a double-well potential. In a quantum two-mode approximation we examine the eigenvectors and eigenvalues and find that the energy correlation diagram indicates a transition from a delocalized to a fragmented regime. Phase-space information is extracted from the stationary quantum states using the Husimi distribution function. We show that the mean-field phase-space characteristics of a nonrigid physical pendulum arises from the exact quantum states, and that only 4-8 particles per well are needed to reach the semiclassical limit. For a driven double-well BEC, we show that the classical chaotic dynamics is manifest in the dynamics of the quantum states. Phase-space analogy also suggests that a {pi} phase-displaced wave packet put on the unstable fixed point on a separatrix bifurcates to create a superposition of two pendulum rotor states--a macroscopic superposition state of BEC. We show that the choice of initial barrier height and ramping, following a {pi} phase imprinting on the condensate, can be used to generate controlled entangled number states with tunable extremity and sharpness.
Integrability of geodesics and action-angle variables in Sasaki-Einstein space T^{1,1}
NASA Astrophysics Data System (ADS)
Visinescu, Mihai
2016-09-01
We briefly describe the construction of Stäkel-Killing and Killing-Yano tensors on toric Sasaki-Einstein manifolds without working out intricate generalized Killing equations. The integrals of geodesic motions are expressed in terms of Killing vectors and Killing-Yano tensors of the homogeneous Sasaki-Einstein space T^{1,1}. We discuss the integrability of geodesics and construct explicitly the action-angle variables. Two pairs of frequencies of the geodesic motions are resonant giving way to chaotic behavior when the system is perturbed.
Non-linear multi-plane wave solutions of self-dual Yang-Mills theory
NASA Astrophysics Data System (ADS)
de Vega, H. J.
1988-12-01
New solutions of self-dual Yang-Mills (SDYM) equations are constructed in Minkowski space-time for the gauge group SL(2, ℂ). After proposing a Lorentz covariant formulation of Yang's equations, a set of Ansätze for exact non-linear multiplane wave solutions are proposed. The gauge fields are rational functions of e x·ki ( K {/i 2}=0, 1≦ i≦ N) for these Ansätze. At least, three families of multisoliton type solutions are derived explicitly. Their asymptotic behaviour shows that non-linear waves scatter non-trivially in Minkowski SDYM.
The kinematic algebra from the self-dual sector
NASA Astrophysics Data System (ADS)
Monteiro, Ricardo; O'Connell, Donal
2011-07-01
We identify a diffeomorphism Lie algebra in the self-dual sector of Yang-Mills theory, and show that it determines the kinematic numerators of tree-level MHV amplitudes in the full theory. These amplitudes can be computed off-shell from Feynman diagrams with only cubic vertices, which are dressed with the structure constants of both the Yang-Mills colour algebra and the diffeomorphism algebra. Therefore, the latter algebra is the dual of the colour algebra, in the sense suggested by the work of Bern, Carrasco and Johansson. We further study perturbative gravity, both in the self-dual and in the MHV sectors, finding that the kinematic numerators of the theory are the BCJ squares of the Yang-Mills numerators.
Quantum tunneling radiation from self-dual black holes
NASA Astrophysics Data System (ADS)
Silva, C. A. S.; Brito, F. A.
2013-10-01
Black holes are considered as objects that can reveal quantum aspects of spacetime. Loop Quantum Gravity (LQG) is a theory that propose a way to model the quantum spacetime behavior revealed by a black hole. One recent prediction of this theory is the existence of sub-Planckian black holes, which have the interesting property of self-duality. This property removes the black hole singularity and replaces it with another asymptotically flat region. In this work, we obtain the thermodynamical properties of this kind of black holes, called self-dual black holes, using the Hamilton-Jacobi version of the tunneling formalism. Moreover, using the tools of the tunneling approach, we investigate the emission spectrum of self-dual black holes, and investigate if some information about the black hole initial state can be recovered during the evaporation process. Back-reaction effects are included.
NASA Astrophysics Data System (ADS)
Hacyan, Shahen
2006-11-01
Since the famous Einstein-Podolsky-Rosen (EPR) paper, it is clear that there is a serious incompatibility between local realism and quantum mechanics. Einstein believed that a complete quantum theory should be free of what he once called "spooky actions at distance". However, all experiments in quantum optics and atomic physics performed in the last two decades confirm the existence of quantum correlations that seem to contradict local realism. According to Bohr, the apparent contradictions disclose only the inadequacy of our customary concepts for the description of the quantum world. Are space and time such customary concepts? In this presentation, I argue that the Copenhagen interpretation is compatible with Kant's transcendental idealism and that, in particular, EPR type paradoxes are consistent with Kant's transcendental aesthetics, according to which space and time have no objective reality but are pure forms of sensible intuition.
Local existence of symmetric spinor potentials for symmetric (3,1)-spinors in Einstein space-times
NASA Astrophysics Data System (ADS)
Andersson, F.; Edgar, S. B.
2001-03-01
We investigate the possibility of existence of a symmetric potential HABA' B' = H( AB)( A' B') for a symmetric (3,1)-spinor LABCA' , e.g., a Lanczos potential of the Weyl spinor, as defined by the equation LABCA' =∇ ( AB' HBC) A' B' . We prove that in all Einstein space-times such a symmetric potential HABA' B' exists. Potentials of this type have been found earlier in investigations of some very special spinors in restricted classes of space-times. A tensor version of this result is also given. We apply similar ideas and results by Illge to Maxwell's equations in a curved space-time.
The Adolescence of Relativity: Einstein, Minkowski, and the Philosophy of Space and Time
NASA Astrophysics Data System (ADS)
Dieks, Dennis
An often repeated account of the genesis of special relativity tells us that relativity theory was to a considerable extent the fruit of an operationalist philosophy of science. Indeed, Einstein's 1905 paper stresses the importance of rods and clocks for giving concrete physical content to spatial and temporal notions. I argue, however, that it would be a mistake to read too much into this. Einstein's operationalist remarks should be seen as serving rhetoric purposes rather than as attempts to promulgate a particular philosophical position - in fact, Einstein never came close to operationalism in any of his philosophical writings. By focussing on what could actually be measured with rods and clocks Einstein shed doubt on the empirical status of a number of pre-relativistic concepts, with the intention to persuade his readers that the applicability of these concepts was not obvious. This rhetoric manoeuvre has not always been rightly appreciated in the philosophy of physics. Thus, the influence of operationalist misinterpretations, according to which associated operations strictly define what a concept means, can still be felt in present-day discussions about the conventionality of simultaneity.The standard story continues by pointing out that Minkowski in 1908 supplanted Einstein's approach with a realist spacetime account that has no room for a foundational role of rods and clocks: relativity theory became a description of a four-dimensional "absolute world." As it turns out, however, it is not at all clear that Minkowski was proposing a substantivalist position with respect to spacetime. On the contrary, it seems that from a philosophical point of view Minkowski's general position was not very unlike the one in the back of Einstein's mind. However, in Minkowski's formulation of special relativity it becomes more explicit that the content of spatiotemporal concepts relates to considerations about the form of physical laws. If accepted, this position has important
Criticality in self-dual sine-Gordon models
NASA Astrophysics Data System (ADS)
Lecheminant, P.; Gogolin, Alexander O.; Nersesyan, Alexander A.
2002-09-01
We discuss the nature of criticality in the β2=2 πN self-dual extension of the sine-Gordon model. This field theory is related to the two-dimensional classical XY model with a N-fold degenerate symmetry-breaking field. We briefly overview the already studied cases N=2,4 and analyze in detail the case N=3 where a single phase transition in the three-state Potts universality class is expected to occur. The Z3 infrared critical properties of the β2=6 π self-dual sine-Gordon model are derived using two non-perturbative approaches. On one hand, we map the model onto an integrable deformation of the Z4 parafermion theory. The latter is known to flow to a massless Z3 infrared fixed point. Another route is based on the connection with a chirally asymmetric, su(2) 4⊗su(2) 1 Wess-Zumino-Novikov-Witten model with anisotropic current-current interaction, where we explore the existence of a decoupling (Toulouse) point.
ERIC Educational Resources Information Center
Range, Shannon K'doah; Mullins, Jennifer
This teaching guide introduces a relativity gyroscope experiment aiming to test two unverified predictions of Albert Einstein's general theory of relativity. An introduction to the theory includes the following sections: (1) "Spacetime, Curved Spacetime, and Frame-Dragging"; (2) "'Seeing' Spacetime with Gyroscopes"; (3) "The Gravity Probe B…
Phase space theory of Bose-Einstein condensates and time-dependent modes
Dalton, B.J.
2012-10-15
A phase space theory approach for treating dynamical behaviour of Bose-Einstein condensates applicable to situations such as interferometry with BEC in time-dependent double well potentials is presented. Time-dependent mode functions are used, chosen so that one, two, Horizontal-Ellipsis highly occupied modes describe well the physics of interacting condensate bosons in time dependent potentials at well below the transition temperature. Time dependent mode annihilation, creation operators are represented by time dependent phase variables, but time independent total field annihilation, creation operators are represented by time independent field functions. Two situations are treated, one (mode theory) is where specific mode annihilation, creation operators and their related phase variables and distribution functions are dealt with, the other (field theory) is where only field creation, annihilation operators and their related field functions and distribution functionals are involved. The field theory treatment is more suitable when large boson numbers are involved. The paper focuses on the hybrid approach, where the modes are divided up between condensate (highly occupied) modes and non-condensate (sparsely occupied) modes. It is found that there are extra terms in the Ito stochastic equations both for the stochastic phases and stochastic fields, involving coupling coefficients defined via overlap integrals between mode functions and their time derivatives. For the hybrid approach both the Fokker-Planck and functional Fokker-Planck equations differ from those derived via the correspondence rules, the drift vectors are unchanged but the diffusion matrices contain additional terms involving the coupling coefficients. Results are also presented for the combined approach where all the modes are treated as one set. Here both the Fokker-Planck and functional Fokker-Planck equations are exactly the same as those derived via the correspondence rules. However, although the
NASA Technical Reports Server (NTRS)
Penin, A. N.; Reutova, T. A.; Sergienko, A. V.
1992-01-01
An experiment on one-photon state localization in space using a correlation technique in Spontaneous Parametric Down Conversion (SPDC) process is discussed. Results of measurements demonstrate an idea of the Einstein-Podolsky-Rosen (EPR) paradox for coordinate and momentum variables of photon states. Results of the experiment can be explained with the help of an advanced wave technique. The experiment is based on the idea that two-photon states of optical electromagnetic fields arising in the nonlinear process of the spontaneous parametric down conversion (spontaneous parametric light scattering) can be explained by quantum mechanical theory with the help of a single wave function.
NASA Astrophysics Data System (ADS)
Hertz, P.
2003-03-01
The Structure and Evolution of the Universe (SEU) theme within NASA's Office of Space Science seeks to explore and understand the dynamic transformations of energy in the Universe - the entire web of biological and physical interactions that determine the evolution of our cosmic habitat. This search for understanding will enrich the human spirit and inspire a new generation of explorers, scientists, and engineers. To that end, NASA's strategic planning process has generated a new Roadmap to enable those goals. Called "Beyond Einstein", this Roadmap identifies three science objectives for the SEU theme: (1) Find out what powered the Big Bang; (2) Observe how black holes manipulate space, time, and matter; and (3) Identify the mysterious dark energy pullingthe Universe apart. These objectives can be realized through a combination of large observatories (Constellation-X, LISA), moderate sized, PI-led missions (the Einstein Probes), and a contuinuing program of technology development, research and analysis, and education/public outreach. In this presentation, NASA's proposed Beyond Einstein Program will be described. The full Roadmap is available at http://universe.nasa.gov/.
Quantum-corrected self-dual black hole entropy in tunneling formalism with GUP
NASA Astrophysics Data System (ADS)
Anacleto, M. A.; Brito, F. A.; Passos, E.
2015-10-01
In this paper we focus on the Hamilton-Jacobi method to determine the entropy of a self-dual black hole by using linear and quadratic GUPs (generalized uncertainty principles). We have obtained the Bekenstein-Hawking entropy of self-dual black holes and its quantum corrections that are logarithm and also of several other types.
Self-dual strings of six-dimensional SCFTs
NASA Astrophysics Data System (ADS)
Lockhart, Guglielmo Paul
In this thesis we aim to characterize the self-dual strings of six-dimensional superconformal field theories (SCFTs) and develop a variety of techniques to compute their elliptic genera, which provide information about their spectra. All known N = (1, 0) supersymmetric SCFTs in 6d can be obtained by compactifying F-theory on an elliptic Calabi-Yau threefold with singular, noncompact base B. Resolving the singularity in B and wrapping D3 branes on the exceptional curves leads to strings on the tensor branch of the SCFT. The strings become tensionless at the superconformal fixed point and appear to play an important role in the dynamics of the SCFT. For a number of SCFTs we identify two-dimensional N = (0, 4) quiver gauge theories describing bound states of self-dual strings and obtain their elliptic genera by localization. We achieve this for 6d SCFTs describing M5 or D5 branes at a singularity, as well as n M5 branes probing an M9 plane (corresponding to n small E8 instantons). More generally, we relate the elliptic genera of strings of 6d SCFTs to the counting of supersymmetric (BPS) particles that arise upon compactification to 5d. This enables us to compute elliptic genera by topological string techniques. Following this approach we obtain information about the strings associated to SCFTs with a single tensor multiplet and minimal gauge group. Additionally, for SCFTs whose strings arise from M2 branes suspended between M5 or M9 branes we find a quantum mechanical picture in which M5 branes or M9 planes are represented by domain wall operators or states; in this context, elliptic genera are expressed in terms of suitable correlators which we compute. Finally, we find a non-perturbative completion of the topological string partition function that can be employed to compute five-sphere partition functions of 5d SCFTs and superconformal indices of 6d SCFTs. In the latter case, we argue that the superconformal index can be written in terms of elliptic genera of the
Stability of anti-de sitter space in Einstein-Gauss-Bonnet gravity.
Deppe, Nils; Kolly, Allison; Frey, Andrew; Kunstatter, Gabor
2015-02-20
Recently it has been argued that in Einstein gravity anti-de Sitter spacetime is unstable against the formation of black holes for a large class of arbitrarily small perturbations. We examine the effects of including a Gauss-Bonnet term. In five dimensions, spherically symmetric Einstein-Gauss-Bonnet gravity has two key features: Choptuik scaling exhibits a radius gap, and the mass function goes to a finite value as the horizon radius vanishes. These suggest that black holes will not form dynamically if the total mass-energy content of the spacetime is too small, thereby restoring the stability of anti-de Sitter spacetime in this context. We support this claim with numerical simulations and uncover a rich structure in horizon radii and formation times as a function of perturbation amplitude. PMID:25763946
Stability of anti-de sitter space in Einstein-Gauss-Bonnet gravity.
Deppe, Nils; Kolly, Allison; Frey, Andrew; Kunstatter, Gabor
2015-02-20
Recently it has been argued that in Einstein gravity anti-de Sitter spacetime is unstable against the formation of black holes for a large class of arbitrarily small perturbations. We examine the effects of including a Gauss-Bonnet term. In five dimensions, spherically symmetric Einstein-Gauss-Bonnet gravity has two key features: Choptuik scaling exhibits a radius gap, and the mass function goes to a finite value as the horizon radius vanishes. These suggest that black holes will not form dynamically if the total mass-energy content of the spacetime is too small, thereby restoring the stability of anti-de Sitter spacetime in this context. We support this claim with numerical simulations and uncover a rich structure in horizon radii and formation times as a function of perturbation amplitude.
Static properties of Bose-Einstein condensate mixtures in semi-infinite space
NASA Astrophysics Data System (ADS)
Thu, Nguyen Van
2016-08-01
Using double-parabola approximation (DPA) applied to Gross-Pitaevskii theory, the interfacial tension of Bose-Einstein condensate mixtures in semi-infinite system is obtained and shows that it is not vanishing at demix state K = 1, its value exactly coincides to wall tension of second component. A new kind of wetting phase transition (Antonov transition) is also considered within DPA and phase transition is first-order. Antonov line is thoroughly proved, too.
Iterative Self-Dual Reconstruction on Radar Image Recovery
Martins, Charles; Medeiros, Fatima; Ushizima, Daniela; Bezerra, Francisco; Marques, Regis; Mascarenhas, Nelson
2010-05-21
Imaging systems as ultrasound, sonar, laser and synthetic aperture radar (SAR) are subjected to speckle noise during image acquisition. Before analyzing these images, it is often necessary to remove the speckle noise using filters. We combine properties of two mathematical morphology filters with speckle statistics to propose a signal-dependent noise filter to multiplicative noise. We describe a multiscale scheme that preserves sharp edges while it smooths homogeneous areas, by combining local statistics with two mathematical morphology filters: the alternating sequential and the self-dual reconstruction algorithms. The experimental results show that the proposed approach is less sensitive to varying window sizes when applied to simulated and real SAR images in comparison with standard filters.
Self-dual Maxwell field in 3D gravity with torsion
Blagojevic, M.; Cvetkovic, B.
2008-08-15
We study the system of a self-dual Maxwell field coupled to 3D gravity with torsion, with the Maxwell field modified by a topological mass term. General structure of the field equations reveals a new, dynamical role of the classical central charges, and gives a simple correspondence between self-dual solutions with torsion and their Riemannian counterparts. We construct two exact self-dual solutions, corresponding to the sectors with a massless and massive Maxwell field, and calculate their conserved charges.
NASA Astrophysics Data System (ADS)
Nematollahi, Delaram; Zhang, Qimin; Altermatt, Joseph; Zhong, Shan; Goodman, Matthew; Bhagat, Anita; Schwettmann, Arne
2016-05-01
We present our apparatus designed to study matter-wave quantum optics in spin space, including our recently finished vacuum system and laser systems. Microwave-dressed spin-exchange collisions in a sodium spinor Bose-Einstein condensate provide a precisely controllable nonlinear interaction that generates squeezing and acts as a source of entanglement. As a consequence of this entanglement between atoms with magnetic quantum numbers m = +1 and m = -1, the noise of population measurements can be reduced below the shot noise. Versatile microwave pulse sequences will be used to implement an interferometer, a phase-sensitive amplifier and other devices. With an added ion detector to detect Rydberg atoms via pulsed-field ionization, we plan to study the effect of Rydberg excitations on the spin evolution of the ultracold gas.
Large N topologically twisted index: necklace quivers, dualities, and Sasaki-Einstein spaces
NASA Astrophysics Data System (ADS)
Hosseini, Seyed Morteza; Mekareeya, Noppadol
2016-08-01
In this paper, we calculate the topological free energy for a number of {N} ≥ 2 Yang-Mills-Chern-Simons-matter theories at large N and fixed Chern-Simons levels. The topological free energy is defined as the logarithm of the partition function of the theory on S 2 × S 1 with a topological A-twist along S 2 and can be reduced to a matrix integral by exploiting the localization technique. The theories of our interest are dual to a variety of Calabi-Yau four-fold singularities, including a product of two asymptotically locally Euclidean singularities and the cone over various well-known homogeneous Sasaki-Einstein seven-manifolds, N 0,1,0, V 5,2, and Q 1,1,1. We check that the large N topological free energy can be matched for theories which are related by dualities, including mirror symmetry and SL(2,{Z}) duality.
Topological self-dual configurations in a Lorentz-violating gauged O (3 ) sigma model
NASA Astrophysics Data System (ADS)
Casana, R.; Farias, C. F.; Ferreira, M. M.
2015-12-01
We have studied the existence of topological Bogomol'nyi-Prasad-Sommerfield or self-dual configurations in a Lorentz-violating gauged O (3 ) nonlinear sigma model, where C P T -even Lorentz-violating (LV) terms were introduced in both the gauge and σ -field sectors. As happens in the usual gauged σ model, purely magnetic self-dual configurations are allowed, maintaining some qualitative features of the standard ones. In a more involved configuration, Lorentz violation provides new self-dual magnetic solutions carrying an electric field but a null total electric charge. In both cases, the total energy of the self-dual configurations turns out to be proportional to the topological charge of the model and to the LV parameters introduced in the σ sector. It is shown that the LV terms yield magnetic flux reversion as well.
Reductions of self-dual Yang-Mills fields and classical systems
NASA Astrophysics Data System (ADS)
Chakravarty, S.; Ablowitz, M. J.; Clarkson, P. A.
1990-08-01
One-dimensional reductions of the self-dual Yang-Mills equations yield various classical systems depending on the choice of the Lie algebra associated with the self-dual fields. Included are the Euler-Arnold equations for rigid bodies in n dimensions, the Kovalevskaya top, and a generalization of the Nahm equation which is related to a classical third-order differential equation possessing a movable natural boundary in the complex plane.
Yao, Yu-Qin; Li, Ji; Han, Wei; Wang, Deng-Shan; Liu, Wu-Ming
2016-01-01
The intrinsic nonlinearity is the most remarkable characteristic of the Bose-Einstein condensates (BECs) systems. Many studies have been done on atomic BECs with time- and space- modulated nonlinearities, while there is few work considering the atomic-molecular BECs with space-modulated nonlinearities. Here, we obtain two kinds of Jacobi elliptic solutions and a family of rational solutions of the atomic-molecular BECs with trapping potential and space-modulated nonlinearity and consider the effect of three-body interaction on the localized matter wave solutions. The topological properties of the localized nonlinear matter wave for no coupling are analysed: the parity of nonlinear matter wave functions depends only on the principal quantum number n, and the numbers of the density packets for each quantum state depend on both the principal quantum number n and the secondary quantum number l. When the coupling is not zero, the localized nonlinear matter waves given by the rational function, their topological properties are independent of the principal quantum number n, only depend on the secondary quantum number l. The Raman detuning and the chemical potential can change the number and the shape of the density packets. The stability of the Jacobi elliptic solutions depends on the principal quantum number n, while the stability of the rational solutions depends on the chemical potential and Raman detuning.
Yao, Yu-Qin; Li, Ji; Han, Wei; Wang, Deng-Shan; Liu, Wu-Ming
2016-01-01
The intrinsic nonlinearity is the most remarkable characteristic of the Bose-Einstein condensates (BECs) systems. Many studies have been done on atomic BECs with time- and space- modulated nonlinearities, while there is few work considering the atomic-molecular BECs with space-modulated nonlinearities. Here, we obtain two kinds of Jacobi elliptic solutions and a family of rational solutions of the atomic-molecular BECs with trapping potential and space-modulated nonlinearity and consider the effect of three-body interaction on the localized matter wave solutions. The topological properties of the localized nonlinear matter wave for no coupling are analysed: the parity of nonlinear matter wave functions depends only on the principal quantum number n, and the numbers of the density packets for each quantum state depend on both the principal quantum number n and the secondary quantum number l. When the coupling is not zero, the localized nonlinear matter waves given by the rational function, their topological properties are independent of the principal quantum number n, only depend on the secondary quantum number l. The Raman detuning and the chemical potential can change the number and the shape of the density packets. The stability of the Jacobi elliptic solutions depends on the principal quantum number n, while the stability of the rational solutions depends on the chemical potential and Raman detuning. PMID:27403634
Atom interferometry using Bose-Einstein condensates on Earth and in space
NASA Astrophysics Data System (ADS)
Sackett, C. A.; Leonard, R. H.; Fallon, A.
2015-03-01
The Cold Atom Laboratory is a multipurpose ultracold gas experiment currently being developed for operation on the international space station. It will have the ability to demonstrate proof-of-principle atom interferometry experiments in space. By using microgravity, atom interferometry has the potential to achieve extremely good performance in sensing and navigation applications. Terrestrial experiments can be used to explore potential challenges and prior to launch. One issue of concern is the release of cold atoms from a magnetic trap into free space. Although the atoms will not fall, they can acquire relatively large velocities due to technical limitations such as stray magnetic fields. This can limit the time available for measurements and thus the atom interferometer performance.
Coset spaces and Einstein manifolds with l-conformal Galilei symmetry
NASA Astrophysics Data System (ADS)
Chernyavsky, Dmitry
2016-10-01
The group theoretic construction is applied to construct a novel dynamical realization of the l-conformal Galilei group in terms of geodesic equations on the coset space. A peculiar feature of the geodesics is that all their integrals of motion, including the accelerations, are functionally independent. The analysis in the recent work [Chernyavsky and Galajinsky (2016) [35
Einstein-Weyl field equations in a Bianchi type-IX space-time
Kolassis, C.A.; Le Denmat, G.
1984-07-15
It is proved that there exists no solution of the combined gravitational-neutrino field equations in general relativity if the space-time metric admits a group of isometries of Bianchi type IX and the neutrino field has geodesic and shearfree rays.
NASA Technical Reports Server (NTRS)
Shih, Y. H.; Sergienko, A. V.; Rubin, M. H.
1993-01-01
A pair of correlated photons generated from parametric down conversion was sent to two independent Michelson interferometers. Second order interference was studied by means of a coincidence measurement between the outputs of two interferometers. The reported experiment and analysis studied this second order interference phenomena from the point of view of Einstein-Podolsky-Rosen paradox. The experiment was done in two steps. The first step of the experiment used 50 psec and 3 nsec coincidence time windows simultaneously. The 50 psec window was able to distinguish a 1.5 cm optical path difference in the interferometers. The interference visibility was measured to be 38 percent and 21 percent for the 50 psec time window and 22 percent and 7 percent for the 3 nsec time window, when the optical path difference of the interferometers were 2 cm and 4 cm, respectively. By comparing the visibilities between these two windows, the experiment showed the non-classical effect which resulted from an E.P.R. state. The second step of the experiment used a 20 psec coincidence time window, which was able to distinguish a 6 mm optical path difference in the interferometers. The interference visibilities were measured to be 59 percent for an optical path difference of 7 mm. This is the first observation of visibility greater than 50 percent for a two interferometer E.P.R. experiment which demonstrates nonclassical correlation of space-time variables.
ADHM construction of (anti-)self-dual instantons in eight dimensions
NASA Astrophysics Data System (ADS)
Nakamula, Atsushi; Sasaki, Shin; Takesue, Koki
2016-09-01
We study the ADHM construction of (anti-)self-dual instantons in eight dimensions. We propose a general scheme to construct the (anti-)self-dual gauge field configurations F ∧ F = ±*8 F ∧ F whose finite topological charges are given by the fourth Chern number. We show that our construction reproduces the known SO (8) one-instanton solution. We also construct multi-instanton solutions of the 't Hooft and the Jackiw-Nohl-Rebbi (JNR) types in the dilute instanton gas approximation. The well-separated configurations of multi-instantons reproduce the correct topological charges with high accuracy. We also show that our construction is generalized to (anti-)self-dual instantons in 4n (n = 3 , 4 , …) dimensions.
Einstein Toolkit for Relativistic Astrophysics
NASA Astrophysics Data System (ADS)
Collaborative Effort
2011-02-01
The Einstein Toolkit is a collection of software components and tools for simulating and analyzing general relativistic astrophysical systems. Such systems include gravitational wave space-times, collisions of compact objects such as black holes or neutron stars, accretion onto compact objects, core collapse supernovae and Gamma-Ray Bursts. The Einstein Toolkit builds on numerous software efforts in the numerical relativity community including CactusEinstein, Whisky, and Carpet. The Einstein Toolkit currently uses the Cactus Framework as the underlying computational infrastructure that provides large-scale parallelization, general computational components, and a model for collaborative, portable code development.
Spin-connection generalized Yang-Mills fields on double-dual generalized Einstein-Cartan backgrounds
NASA Astrophysics Data System (ADS)
O'Brien, G. M.; Tchrakian, D. H.
1988-05-01
In every even dimension, a modification of the generalized Yang-Mills systems (modGYM) is introduced. It is shown that spin-connection modGYM fields, which are self-dual on a double-self-dual background of generalized Einstein-Cartan (GEC) gravity, can be constructed—this generalizes the constructions of Charap and Duff [Phys. Lett. B 69, 445 (1977)] in four dimensions, to all even dimensions. Additional duality constraints are also given that must be satisfied by the gravitational fields, if these constructions are to apply also to the full GYM systems. Applications to compactification, as well as relevant physical criteria, are briefly discussed.
Maxwell-Higgs self-dual solitons on an infinite cylinder
NASA Astrophysics Data System (ADS)
Casana, Rodolfo; Sourrouille, Lucas
2015-07-01
We have studied the Maxwell-Higgs model on the surface of an infinite cylinder. In particular, we show that this model supports self-dual topological soliton solutions on the infinite tube. Finally, the Bogomol’nyi-type equations are studied from theoretical and numerical point of view.
ERIC Educational Resources Information Center
Ryder, L. H.
1987-01-01
Discusses the history of scientific thought in terms of the theories of inertia and absolute space, relativity and gravitation. Describes how Sir Isaac Newton used the work of earlier scholars in his theories and how Albert Einstein used Newton's theories in his. (CW)
ERIC Educational Resources Information Center
Carlson, Eric; Wald, Robert
1979-01-01
Presents a guide to be used by students and teachers in conjunction with a television program about Einstein. Provides general information about special and general relativity, and the universe. Includes questions for discussion after each section and a bibliography. (MA)
None
2016-07-12
CommÃ©moration de A.Einstein avec 4 orateurs pour honnorer sa mÃ©moire: le prof.Weisskopf parlera de l'homme de science engagÃ©, Daniel Amati du climat de la physique aux annÃ©es 1920, Sergio Fubini de l'heure scientifique d'A.Einstein et le prof.Berob(?)
NASA Astrophysics Data System (ADS)
Lomnitz, C.
2007-05-01
What does Einstein have to do with subduction? Good question. Peaceful Lake Budi, lying at the heart of an Indian reservation in the Deep South of Chile, had subsided by two meters in the 1960 mega-thrust earthquake. This unique South American salt lake was hiding an awful secret: it was actually an oxbow, not a lake. But Einstein had realized in 1926 that meanders are natural freaks. Rivers will not flow uphill, yet - he claimed - they don't flow down the path of steepest descent either. This anomaly was put at the doorstep of a weak Coriolis Force. Thus Einstein problematized the dilemma of the earth sciences. How can a non-force produce margin-parallel compression in a convergent margin where extension is expected? In fact, where does the energy for meander formation come from? Good question . . . Even Wikipedia knows that Coriolis is not a “force” but an “effect”. So is the obliquity of plate convergence in subduction. Where did Einstein err, and where was he a pioneer? Coastal ablation plus alternating subsidence and emergence in giant earthquakes may yield an answer. Einstein, A. (1926). Die Ursache der Maeanderbildung der Flusslaeufe und das sogenannte Baersche Gesetz, Naturwissenschaften, 14, fascicle II.
Fedichev, Petr O; Fischer, Uwe R
2003-12-12
We propose an experimental scheme to observe the Gibbons-Hawking effect in the acoustic analog of a (1+1)-dimensional de Sitter universe, produced in an expanding, cigar-shaped Bose-Einstein condensate. It is shown that a two-level system created at the center of the trap, an atomic quantum dot interacting with phonons, observes a thermal Bose distribution at the de Sitter temperature.
Fedichev, Petr O; Fischer, Uwe R
2003-12-12
We propose an experimental scheme to observe the Gibbons-Hawking effect in the acoustic analog of a (1+1)-dimensional de Sitter universe, produced in an expanding, cigar-shaped Bose-Einstein condensate. It is shown that a two-level system created at the center of the trap, an atomic quantum dot interacting with phonons, observes a thermal Bose distribution at the de Sitter temperature. PMID:14683099
Solutions to Yang—Mills equations that are not self-dual
Sibner, L. M.; Sibner, R. J.; Uhlenbeck, K.
1989-01-01
The Yang—Mills functional for connections on principle SU(2) bundles over S4 is studied. Critical points of the functional satisfy a system of second-order partial differential equations, the Yang—Mills equations. If, in particular, the critical point is a minimum, it satisfies a first-order system, the self-dual or anti-self-dual equations. Here, we exhibit an infinite number of finite-action nonminimal unstable critical points. They are obtained by constructing a topologically nontrivial loop of connections to which min—max theory is applied. The construction exploits the fundamental relationship between certain invariant instantons on S4 and magnetic monopoles on H3. This result settles a question in gauge field theory that has been open for many years. PMID:16594082
Vortex dynamics in self-dual Chern-Simons-Higgs systems
Kim, Y. ); Lee, K. )
1994-02-15
We consider vortex dynamics in self-dual Chern-Simons-Higgs systems. We show that the naive Aharonov-Bohm phase is the inverse of the statistical phase expected from the vortex spin, and that the self-dual configurations of vortices are degenerate in energy but not in angular momentum. We also use the path integral formalism to derive the dual formulation of Chern-Simons-Higgs systems in which vortices appear as charged particles. We argue that in addition to the electromagnetic interaction, there is an additional interaction between vortices, the so-called Magnus force, and that these forces can be put together into a single dual electromagnetic'' interaction. This dual electromagnetic interaction leads to the right statistical phase. We also derive and study the effective action for slowly moving vortices, which contains terms both linear and quadratic in the vortex velocity. We show that vortices can be bounded to each other by the Magnus force.
Nonlinear periodic waves solutions of the nonlinear self-dual network equations
Laptev, Denis V. Bogdan, Mikhail M.
2014-04-15
The new classes of periodic solutions of nonlinear self-dual network equations describing the breather and soliton lattices, expressed in terms of the Jacobi elliptic functions have been obtained. The dependences of the frequencies on energy have been found. Numerical simulations of soliton lattice demonstrate their stability in the ideal lattice and the breather lattice instability in the dissipative lattice. However, the lifetime of such structures in the dissipative lattice can be extended through the application of ac driving terms.
ERIC Educational Resources Information Center
Fine, Leonard
2005-01-01
A brief description on the work and life of the great physicist scientist Albert Einstein is presented. The photoelectric paper written by him in 1905 led him to the study of fluctuations in the energy density of radiation and from there to the incomplete nature of the equipartition theorem of classical mechanics, which failed to account for…
ERIC Educational Resources Information Center
Gjurchinovski, Aleksandar; Skeparovski, Aleksandar
2008-01-01
Reflection of light from a plane mirror in uniform rectilinear motion is a century-old problem, intimately related to the foundations of special relativity. The problem was first investigated by Einstein in his famous 1905 paper by using the Lorentz transformations to switch from the mirror's rest frame to the frame where the mirror moves at a…
The NASA Beyond Einstein Program
NASA Technical Reports Server (NTRS)
White, Nicholas E.
2004-01-01
The Laser Interferometer Space Antenna (LISA) mission is part of NASA s Beyond Einstein program. This program seeks to answer the questions What Powered the Big Bang?, What happens at the edge of a Black Hole?, and What is Dark Energy?. LISA IS the first mission to be launched in this new program. This paper will give an overview of the Beyond Einstein program, its current status and where LISA fits in.
The NASA Beyond Einstein Program
NASA Technical Reports Server (NTRS)
White, Nicholas E.
2006-01-01
Einstein's legacy is incomplete, his theory of General relativity raises -- but cannot answer --three profound questions: What powered the big bang? What happens to space, time, and matter at the edge of a black hole? and What is the mysterious dark energy pulling the Universe apart? The Beyond Einstein program within NASA's Office of Space Science aims to answer these questions, employing a series of missions linked by powerful new technologies and complementary approaches towards shared science goals. The Beyond Einstein program has three linked elements which advance science and technology towards two visions; to detect directly gravitational wave signals from the earliest possible moments of the BIg Bang, and to image the event horizon of a black hole. The central element is a pair of Einstein Great Observatories, Constellation-X and LISA. Constellation-X is a powerful new X-ray observatory dedicated to X-Ray Spectroscopy. LISA is the first spaced based gravitational wave detector. These powerful facilities will blaze new paths to the questions about black holes, the Big Bang and dark energy. The second element is a series of competitively selected Einstein Probes, each focused on one of the science questions and includes a mission dedicated resolving the Dark Energy mystery. The third element is a program of technology development, theoretical studies and education. The Beyond Einstein program is a new element in the proposed NASA budget for 2004. This talk will give an overview of the program and the missions contained within it.
NASA Astrophysics Data System (ADS)
Hendi, S. H.; Tad, R. Moradi; Armanfard, Z.; Talezadeh, M. S.
2016-05-01
Motivated by a thermodynamic analogy of black holes and Van der Waals liquid/gas systems, in this paper, we study P- V criticality of both dilatonic Born-Infeld black holes and their conformal solutions, Brans-Dicke-Born-Infeld solutions. Due to the conformal constraint, we have to neglect the old Lagrangian of dilatonic Born-Infeld theory and its black hole solutions, and introduce a new one. We obtain spherically symmetric nonlinearly charged black hole solutions in both Einstein and Jordan frames and then we calculate the related conserved and thermodynamic quantities. After that, we extend the phase space by considering the proportionality of the cosmological constant and thermodynamical pressure. We obtain critical values of the thermodynamic coordinates through numerical methods and plot the relevant P- V and G- T diagrams. Investigation of the mentioned diagrams helps us to study the thermodynamical phase transition. We also analyze the effects of varying different parameters on the phase transition of black holes.
Piecewise linear manifolds: Einstein metrics and Ricci flows
NASA Astrophysics Data System (ADS)
Schrader, Robert
2016-05-01
This article provides an attempt to extend concepts from the theory of Riemannian manifolds to piecewise linear (p.l.) spaces. In particular we propose an analogue of the Ricci tensor, which we give the name of an Einstein vector field. On a given set of p.l. spaces we define and discuss (normalized) Einstein flows. p.l. Einstein metrics are defined and examples are provided. Criteria for flows to approach Einstein metrics are formulated. Second variations of the total scalar curvature at a specific Einstein space are calculated. Dedicated to Ludwig Faddeev on the occasion of his 80th birthday.
NASA Astrophysics Data System (ADS)
Miller, Arthur I.
2004-11-01
How the 20th century’s most important scientist—Albert Einstein—and its most important artist—Pablo Picasso—made their greatest discoveries at almost the same time is a remarkable story: Einstein's relativity theory in 1905 and Picasso's Les Demoiselles d'Avignon two years later. A scientist and an artist confronted the same problem—the nature of time and simultaneity—and resolved it after realizing a new aesthetic. At the nascent moment of creativity boundaries dissolve between disciplines. This article explores the similarities in the early work of two of the greatest icons of Art and Science of the last century.
Spherically symmetric black holes in minimally modified self-dual gravity
NASA Astrophysics Data System (ADS)
Ishibashi, Akihiro; Speziale, Simone
2009-09-01
We discuss spherically symmetric black holes in the modified self-dual theory of gravity recently studied by Krasnov, obtained by adding a Weyl curvature- dependent 'cosmological term' to the Plebanski lagrangian for general relativity. This type of modified gravity admits two different types of singularities: one is a true singularity for the theory where the fundamental fields of the theory, as well as the (auxiliary) spacetime metric, become singular, and the other one is a milder 'non-metric singularity' where the metric description of the spacetime breaks down but the fundamental fields themselves are regular. We first generalize this modified self-dual gravity to include Maxwell's field and then study the basic features of spherically symmetric, charged black holes, with particular focus on whether these two types of singularities are hidden or naked. We restrict our attention to minimal forms of the modification, and find that the theory exhibits 'screening' effects of the electric charge (or 'anti-screening', depending upon the sign of the modification term), in the sense that it leads to the possibility of charging the black hole more (or less) than it would be possible in general relativity without exposing a naked singularity. We also find that for any (even arbitrarily large) value of charge, true singularities of the theory appear to be either achronal (non-timelike) covered by the hypersurface of a harmless non-metric singularity or simply hidden inside at least one Killing horizon.
NASA Astrophysics Data System (ADS)
Mišković, Olivera; Olea, Rodrigo
2011-01-01
Motivated by possible applications within the framework of anti-de Sitter gravity/conformal field theory correspondence, charged black holes with AdS asymptotics, which are solutions to Einstein-Gauss-Bonnet gravity in D dimensions, and whose electric field is described by nonlinear electrodynamics are studied. For a topological static black hole ansatz, the field equations are exactly solved in terms of the electromagnetic stress tensor for an arbitrary nonlinear electrodynamic Lagrangian in any dimension D and for arbitrary positive values of Gauss-Bonnet coupling. In particular, this procedure reproduces the black hole metric in Born-Infeld and conformally invariant electrodynamics previously found in the literature. Altogether, it extends to D>4 the four-dimensional solution obtained by Soleng in logarithmic electrodynamics, which comes from vacuum polarization effects. Falloff conditions for the electromagnetic field that ensure the finiteness of the electric charge are also discussed. The black hole mass and vacuum energy as conserved quantities associated to an asymptotic timelike Killing vector are computed using a background-independent regularization of the gravitational action based on the addition of counterterms which are a given polynomial in the intrinsic and extrinsic curvatures.
Iyer, Ramakrishnan; Mukhopadhyay, Ayan
2010-04-15
The AdS/CFT correspondence defines a sector with universal strongly coupled dynamics in the field theory as the dual of pure gravity in AdS described by Einstein's equation with a negative cosmological constant. We explain here, from the field-theoretic viewpoint how the dynamics in this sector gets determined by the expectation value of the energy-momentum tensor alone. We first show that the Boltzmann equation has very special solutions which could be functionally completely determined in terms of the energy-momentum tensor alone. We call these solutions conservative solutions. We indicate why conservative solutions should also exist when we refine this kinetic description to go closer to the exact microscopic theory or even move away from the regime of weak coupling so that no kinetic description could be employed. We argue that these conservative solutions form the universal sector dual to pure gravity at strong coupling and large N. Based on this observation, we propose a regularity condition on the energy-momentum tensor so that the dual solution in pure gravity has a smooth future horizon. We also study if irreversibility emerges only at long time scales of observation, unlike the case of the Boltzmann equation.
Miskovic, Olivera; Olea, Rodrigo
2011-01-15
Motivated by possible applications within the framework of anti-de Sitter gravity/conformal field theory correspondence, charged black holes with AdS asymptotics, which are solutions to Einstein-Gauss-Bonnet gravity in D dimensions, and whose electric field is described by nonlinear electrodynamics are studied. For a topological static black hole ansatz, the field equations are exactly solved in terms of the electromagnetic stress tensor for an arbitrary nonlinear electrodynamic Lagrangian in any dimension D and for arbitrary positive values of Gauss-Bonnet coupling. In particular, this procedure reproduces the black hole metric in Born-Infeld and conformally invariant electrodynamics previously found in the literature. Altogether, it extends to D>4 the four-dimensional solution obtained by Soleng in logarithmic electrodynamics, which comes from vacuum polarization effects. Falloff conditions for the electromagnetic field that ensure the finiteness of the electric charge are also discussed. The black hole mass and vacuum energy as conserved quantities associated to an asymptotic timelike Killing vector are computed using a background-independent regularization of the gravitational action based on the addition of counterterms which are a given polynomial in the intrinsic and extrinsic curvatures.
Sakaguchi, Hidetsugu; Li, Ben; Malomed, Boris A
2014-03-01
It is commonly known that two-dimensional mean-field models of optical and matter waves with cubic self-attraction cannot produce stable solitons in free space because of the occurrence of collapse in the same setting. By means of numerical analysis and variational approximation, we demonstrate that the two-component model of the Bose-Einstein condensate with the spin-orbit Rashba coupling and cubic attractive interactions gives rise to solitary-vortex complexes of two types: semivortices (SVs, with a vortex in one component and a fundamental soliton in the other), and mixed modes (MMs, with topological charges 0 and ±1 mixed in both components). These two-dimensional composite modes can be created using the trapping harmonic-oscillator (HO) potential, but remain stable in free space, if the trap is gradually removed. The SVs and MMs realize the ground state of the system, provided that the self-attraction in the two components is, respectively, stronger or weaker than the cross attraction between them. The SVs and MMs which are not the ground states are subject to a drift instability. In free space (in the absence of the HO trap), modes of both types degenerate into unstable Townes solitons when their norms attain the respective critical values, while there is no lower existence threshold for the stable modes. Moving free-space stable solitons are also found in the present non-Galilean-invariant system, up to a critical velocity. Collisions between two moving solitons lead to their merger into a single one.
Spherically symmetric self-dual Yang-Mills instantons on curved backgrounds in all even dimensions
Radu, Eugen; Tchrakian, D. H.; Yang Yisong
2008-02-15
We present several different classes of self-dual Yang-Mills instantons in all even d-dimensional backgrounds with Euclidean signature. In d=4p+2 the only solutions we found are on constant curvature dS (de Sitter) and AdS (anti-de Sitter) backgrounds and are evaluated in closed form. In d=4p an interesting class of instantons are given on black hole backgrounds. One class of solutions are (Euclidean) time-independent and spherically symmetric in d-1 dimensions, and the other class are spherically symmetric in all d dimensions. Some of the solutions in the former class are evaluated numerically, all the rest being given in closed form. Analytic proofs of existence covering all numerically evaluated solutions are given. All instantons studied have finite action and vanishing energy momentum tensor and do not disturb the geometry.
NASA Astrophysics Data System (ADS)
Bellac, Michel Le
2014-11-01
The final form of quantum physics, in the particular case of wave mechanics, was established in the years 1925-1927 by Heisenberg, Schrödinger, Born and others, but the synthesis was the work of Bohr who gave an epistemological interpretation of all the technicalities built up over those years; this interpretation will be examined briefly in Chapter 10. Although Einstein acknowledged the success of quantum mechanics in atomic, molecular and solid state physics, he disagreed deeply with Bohr's interpretation. For many years, he tried to find flaws in the formulation of quantum theory as it had been more or less accepted by a large majority of physicists, but his objections were brushed away by Bohr. However, in an article published in 1935 with Podolsky and Rosen, universally known under the acronym EPR, Einstein thought he had identified a difficulty in the by then standard interpretation. Bohr's obscure, and in part beyond the point, answer showed that Einstein had hit a sensitive target. Nevertheless, until 1964, the so-called Bohr-Einstein debate stayed uniquely on a philosophical level, and it was actually forgotten by most physicists, as the few of them aware of it thought it had no practical implication. In 1964, the Northern Irish physicist John Bell realized that the assumptions contained in the EPR article could be tested experimentally. These assumptions led to inequalities, the Bell inequalities, which were in contradiction with quantum mechanical predictions: as we shall see later on, it is extremely likely that the assumptions of the EPR article are not consistent with experiment, which, on the contrary, vindicates the predictions of quantum physics. In Section 3.2, the origin of Bell's inequalities will be explained with an intuitive example, then they will be compared with the predictions of quantum theory in Section 3.3, and finally their experimental status will be reviewed in Section 3.4. The debate between Bohr and Einstein goes much beyond a
NASA Astrophysics Data System (ADS)
Graev, M. M.
2007-04-01
To every homogeneous space M=G/H of a Lie group G with a compact isotropy group H, where the isotropy representation consists of d irreducible components of multiplicity 1, we assign a compact convex polytope P=P_M in \\mathbb R^{d-1}, namely, the Newton polytope of the rational function s(t) defined to be the scalar curvature of the invariant metric t on M. If G is a compact semisimple group, then the ratio of the volume of P to the volume of the standard (d-1)-simplex is a positive integer \
Posing Einstein's Question: Questioning Einstein's Pose.
ERIC Educational Resources Information Center
Topper, David; Vincent, Dwight E.
2000-01-01
Discusses the events surrounding a famous picture of Albert Einstein in which he poses near a blackboard containing a tensor form of his 10 field equations for pure gravity with a question mark after it. Speculates as to the content of Einstein's lecture and the questions he might have had about the equation. (Contains over 30 references.) (WRM)
Schwinger's Approach to Einstein's Gravity
NASA Astrophysics Data System (ADS)
Milton, Kim
2012-05-01
Albert Einstein was one of Julian Schwinger's heroes, and Schwinger was greatly honored when he received the first Einstein Prize (together with Kurt Godel) for his work on quantum electrodynamics. Schwinger contributed greatly to the development of a quantum version of gravitational theory, and his work led directly to the important work of (his students) Arnowitt, Deser, and DeWitt on the subject. Later in the 1960's and 1970's Schwinger developed a new formulation of quantum field theory, which he dubbed Source Theory, in an attempt to get closer contact to phenomena. In this formulation, he revisited gravity, and in books and papers showed how Einstein's theory of General Relativity emerged naturally from one physical assumption: that the carrier of the gravitational force is a massless, helicity-2 particle, the graviton. (There has been a minor dispute whether gravitational theory can be considered as the massless limit of a massive spin-2 theory; Schwinger believed that was the case, while Van Dam and Veltman concluded the opposite.) In the process, he showed how all of the tests of General Relativity could be explained simply, without using the full machinery of the theory and without the extraneous concept of curved space, including such effects as geodetic precession and the Lense-Thirring effect. (These effects have now been verified by the Gravity Probe B experiment.) This did not mean that he did not accept Einstein's equations, and in his book and full article on the subject, he showed how those emerge essentially uniquely from the assumption of the graviton. So to speak of Schwinger versus Einstein is misleading, although it is true that Schwinger saw no necessity to talk of curved spacetime. In this talk I will lay out Schwinger's approach, and the connection to Einstein's theory.
ERIC Educational Resources Information Center
Caulley, Darrel N.
1982-01-01
Like any other person, Albert Einstein was an informal evaluator, engaged in placing value on various aspects of his life, work, and the world. Based on Einstein's own statements, this paper speculates about what Einstein would have been like as a connoisseur evaluator, a conceptual evaluator, or a responsive evaluator. (Author/BW)
Self-dual black holes in loop quantum gravity: Theory and phenomenology
Modesto, Leonardo; Premont-Schwarz, Isabeau
2009-09-15
In this paper we have recalled the semiclassical metric obtained from a classical analysis of the loop quantum black hole (LQBH). We show that the regular Reissner-Nordstroem-like metric is self-dual in the sense of T-duality: the form of the metric obtained in loop quantum gravity is invariant under the exchange r{yields}a{sub 0}/r where a{sub 0} is proportional to the minimum area in loop quantum gravity and r is the standard Schwarzschild radial coordinate at asymptotic infinity. Of particular interest, the symmetry imposes that if an observer in r{yields}+{infinity} sees a black hole of mass m an observer in the other asymptotic infinity beyond the horizon (at r{approx_equal}0) sees a dual mass m{sub P}/m. We then show that small LQBH are stable and could be a component of dark matter. Ultralight LQBHs created shortly after the big bang would now have a mass of approximately 10{sup -5}m{sub P} and emit radiation with a typical energy of about 10{sup 13}-10{sup 14} eV but they would also emit cosmic rays of much higher energies, albeit few of them. If these small LQBHs form a majority of the dark matter of the Milky Way's Halo, the production rate of ultra-high-energy-cosmic-rays (UHECR) by these ultralight black holes would be compatible with the observed rate of the Auger detector.
Einstein's Biggest Blunder: A Cosmic Mystery Story
Krauss, Lawrence
2016-07-12
The standard model of cosmology built up over 20 years is no longer accepted as accurate. New data suggest that most of the energy density of the universe may be contained in empty space. Remarkably, this is exactly what would be expected if Einstein's cosmological constant really exists. If it does, its origin is the biggest mystery in physics and presents huge challenges for the fundamental theories of elementary particles and fields. Krauss explains Einstein's concept and describes its possible implications.
The existence of self-dual vortices in a non-Abelian {Phi}{sup 2} Chern-Simons theory
Chen Shouxin; Wang Ying
2010-09-15
Applying the dynamic shooting method, we proved the existence of nontopological radially symmetric n-vortex solutions to the self-dual equation in non-Abelian Chern-Simons gauge theory with a {Phi}{sup 2}-type potential. Moreover, we obtained all possible radially symmetric nontopological bare (or 0-vortex) solutions in the non-Abelian Chern-Simons model. Meanwhile, we established the asymptotic behavior for the solutions as |x|{yields}{infinity}.
Wang, L. C.
1980-01-01
Bäecklund Transformations (BT) and the derivation of local conservation laws are first reviewed in the classic case of the Sine-Gordon equation. The BT, conservation laws (local and nonlocal), and the inverse-scattering formulation are discussed for the chiral and the self-dual Yang-Mills fields. Their possible applications to the loop formulation for the Yang-Mills fields are mentioned. 55 references, 1 figure.
Universal behavior of the Shannon mutual information in nonintegrable self-dual quantum chains
NASA Astrophysics Data System (ADS)
Alcaraz, F. C.
2016-09-01
An existing conjecture states that the Shannon mutual information contained in the ground-state wave function of conformally invariant quantum chains, on periodic lattices, has a leading finite-size scaling behavior that, similarly as the von Neumann entanglement entropy, depends on the value of the central charge of the underlying conformal field theory describing the physical properties. This conjecture applies whenever the ground-state wave function is expressed in some special basis (conformal basis). Its formulation comes mainly from numerical evidences on exactly integrable quantum chains. In this paper, the above conjecture was tested for several general nonintegrable quantum chains. We introduce new families of self-dual Z (Q ) symmetric quantum chains (Q =2 ,3 ,... ). These quantum chains contain nearest-neighbor as well next-nearest-neighbor interactions (coupling constant p ). In the cases Q =2 and Q =3 , they are extensions of the standard quantum Ising and three-state Potts chains, respectively. For Q =4 and Q ≥5 , they are extensions of the Ashkin-Teller and Z (Q ) parafermionic quantum chains. Our studies indicate that these models are interesting on their own. They are critical, conformally invariant, and share the same universality class in a continuous critical line. Moreover, our numerical analysis for Q =2 -8 indicate that the Shannon mutual information exhibits the conjectured behavior irrespective if the conformally invariant quantum chain is exactly integrable or not. For completeness we also calculated, for these new families of quantum chains, the two existing generalizations of the Shannon mutual information, which are based on the Rényi entropy and on the Rényi divergence.
NASA Astrophysics Data System (ADS)
Werner, M. C.; An, J.; Evans, N. W.
2008-12-01
A number of recent surveys for gravitational lenses have found examples of double Einstein rings. Here, we analytically investigate the occurrence of multiple Einstein rings. We prove, under very general assumptions, that at the most one Einstein ring can arise from a mass distribution in a single plane lensing a single background source. Two or more Einstein rings can therefore only occur in multiplane lensing. Surprisingly, we show that it is possible for a single source to produce more than one Einstein ring. If two point masses, or two isothermal spheres, in different planes are aligned with observer and source on the optical axis, we show that there are up to three Einstein rings. We also discuss the image morphologies for these two models if axisymmetry is broken, and give the first instances of magnification invariants in the case of two-lens planes.
Neuromythology of Einstein's brain.
Hines, Terence
2014-07-01
The idea that the brain of the great physicist Albert Einstein is different from "average" brains in both cellular structure and external shape is widespread. This belief is based on several studies examining Einstein's brain both histologically and morphologically. This paper reviews these studies and finds them wanting. Their results do not, in fact, provide support for the claim that the structure of Einstein's brain reflects his intellectual abilities.
Unifying Einstein and Palatini gravities
Amendola, Luca; Enqvist, Kari; Koivisto, Tomi
2011-02-15
We consider a novel class of f(R) gravity theories where the connection is related to the conformally scaled metric g{sub {mu}{nu}=}C(R)g{sub {mu}{nu}} with a scaling that depends on the scalar curvature R only. We call them C theories and show that the Einstein and Palatini gravities can be obtained as special limits. In addition, C theories include completely new physically distinct gravity theories even when f(R)=R. With nonlinear f(R), C theories interpolate and extrapolate the Einstein and Palatini cases and may avoid some of their conceptual and observational problems. We further show that C theories have a scalar-tensor formulation, which in some special cases reduces to simple Brans-Dicke-type gravity. If matter fields couple to the connection, the conservation laws in C theories are modified. The stability of perturbations about flat space is determined by a simple condition on the Lagrangian.
Static spacetimes with Einstein surfaces in 4d Einstein-Maxwell-Higgs theory with general couplings
NASA Astrophysics Data System (ADS)
Gunara, Bobby Eka
2015-04-01
Static spacetimes of four dimensional Einstein-Maxwell-Higgs theory with general couplings can be thought of as static black holes and static domain walls. In this paper, we study a static spacetime where the two-surface is in general to be Einstein. In particular, if the scalars are frozen everywhere in the spacetime which can be viewed as the critical points of the black hole and the scalar potentials, then the geometries are of a constant scalar curvature which in general are not Einstein describing charged black holes. Whereas, in the case of charged domain walls the scalars are frozen in the asymptotic region describing spaces of constant scalar curvature.
BOOK REVIEW: Once Upon Einstein
NASA Astrophysics Data System (ADS)
Giannetto, E.
2007-07-01
(pp 17--21, 48--52 and related endnotes): had Henri Poincaré constructed a special relativistic dynamics before Einstein? There is a long debate on this subject in the literature. Damour's answer is negative and his conclusions seem related to the conservation of a myth of Einstein, that is, the rise of special relativity is considered as a creatio ex nihilo within Einstein's mind and Einstein is considered as the only genius able to conceive the relativity of time. Poincaré's texts are undervalued and misunderstood by Damour's cutting quotations from their context. Damour never quotes La Science et l'Hypothèse (1902): we know it was read by Einstein and here Poincaré first (within chapters already published as separate papers in 1900) stated the relativity of time and of simultaneity. Damour never quotes Poincaré's paper published on 5 June 1905, La dynamique de l'èlectron, which presents the first relativistic dynamics, invariant by Lorentz transformations. Poincaré's (July 1905) introduction of a quadrimensional space-time is considered by Damour only a mathematical artifice (p 51) and Damour never said that Minkowski took this idea from Poincaré! Poincaré's interpretation of relativistic time implies that it is not an illusion but a complex net of different real flows related to different processes. Poincaré and Einstein had different conceptions of Nature at the root of special relativity: respectively an electromagnetic conception (Poincaré) and a semi-mechanist one (Einstein). Thus, the (philosophical) meaning of relativity can be very different from the one presented by Damour. Furthermore, Damour accepts Kantian philosophy as a key to understanding relativity and quantum theories. This perspective seems to me very anachronistic and based on a misunderstanding: an interpretation of 20th century physical theories (relativity and quantum physics) is given within the framework of an 18th century philosophical perspective, created to give a foundation
Generating solutions to the Einstein field equations
NASA Astrophysics Data System (ADS)
Contopoulos, I. G.; Esposito, F. P.; Kleidis, K.; Papadopoulos, D. B.; Witten, L.
2016-11-01
Exact solutions to the Einstein field equations may be generated from already existing ones (seed solutions), that admit at least one Killing vector. In this framework, a space of potentials is introduced. By the use of symmetries in this space, the set of potentials associated to a known solution is transformed into a new set, either by continuous transformations or by discrete transformations. In view of this method, and upon consideration of continuous transformations, we arrive at some exact, stationary axisymmetric solutions to the Einstein field equations in vacuum, that may be of geometrical or/and physical interest.
Piccioni, Robert
2010-10-05
Young Einstein was a rebel who seemed doomed to fail. How did he overcome rejection to become the most famous scientist in history? We will discuss and explain all his theories in plain English and without math, and we will discover how Einstein's achievements impact our lives through DVDs, GPS, iPods, computers and green energy.
NASA Astrophysics Data System (ADS)
Klein, Martin J.
2005-03-01
After Paul Ehrenfest's untimely death, Albert Einstein wrote about their first meeting more than twenty years earlier. ``Within a few hours we were true friends as though our dreams and aspirations were meant for each other.'' In fact, this warm friendship with a fellow theoretical physicist of his own age was unique in Einstein's life. I shall try to characterize it in this talk.
Piccioni, Robert
2016-07-12
Young Einstein was a rebel who seemed doomed to fail. How did he overcome rejection to become the most famous scientist in history? We will discuss and explain all his theories in plain English and without math, and we will discover how Einstein's achievements impact our lives through DVDs, GPS, iPods, computers and green energy.
ERIC Educational Resources Information Center
Science Scope, 2006
2006-01-01
This article deals with a pale blue sculpture entitled "A New World View", as an homage to the most famous scientist in modern history, Albert Einstein. It has 32 bas-relief squares composed of glass and steel that represent one aspect of the life and legacy of Albert Einstein. Images of children's faces peer out from behind the glass squares,…
NASA Astrophysics Data System (ADS)
Lisle, John
2016-01-01
Albert Einstein's biographers have not explained why he developed the abdominal aortic aneurysm that led to his death. Early conjectures proposed that it was caused by syphilis, without accurate evidence. The present article gives evidence to the contrary, and argues that the principal cause of Einstein's death was smoking.
NASA Astrophysics Data System (ADS)
Bond, P.; Murdin, P.
2002-04-01
The second in the series of HIGH ENERGY ASTROPHYSICAL OBSERVATORIES was launched by an Atlas-Centaur rocket on 13 November 1978. Soon after its insertion into a 470 km circular orbit inclined at 23.5° to the equator, HEAO-2 was named the Einstein Observatory, in celebration of the centenary of Albert Einstein's birth....
Einstein, Mach, and the Fortunes of Gravity
NASA Astrophysics Data System (ADS)
Kaiser, David
2005-04-01
Early in his life, Albert Einstein considered himself a devoted student of the physicist and philosopher Ernst Mach. Mach's famous critiques of Newton's absolute space and time -- most notably Mach's explanation of Newton's bucket experiment -- held a strong sway over Einstein as he struggled to formulate general relativity. Einstein was convinced that his emerging theory of gravity should be consistent with Mach's principle, which states that local inertial effects arise due to gravitational interactions with distant matter. Once completed, Einstein's general relativity enjoyed two decades of worldwide attention, only to fall out of physicists' interest during the 1930s and 1940s, when topics like nuclear physics claimed center stage. Gravity began to return to the limelight during the 1950s and especially the 1960s, and once again Mach proved to be a major spur: Princeton physicists Carl Brans and Robert Dicke introduced a rival theory of gravity in 1961 which they argued satisfied Mach's principle better than Einstein's general relativity did. The Brans-Dicke theory, and the new generation of experiments designed to test its predictions against those of general relativity, played a major role in bringing Einstein's beloved topic back to the center of physics.
Einstein metrics and Brans-Dicke superfields
Marques, S.
1988-01-01
It is obtained here a space conformal to the Einstein space-time, making the transition from an internal bosonic space, constructed with the Majorana constant spinors in the Majorana representation, to a bosonic ''superspace,'' through the use of Einstein vierbeins. These spaces are related to a Grassmann space constructed with the Majorana spinors referred to above, where the ''metric'' is a function of internal bosonic coordinates. The conformal function is a scale factor in the zone of gravitational radiation. A conformal function dependent on space-time coordinates can be constructed in that region when we introduce Majorana spinors which are functions of those coordinates. With this we obtain a scalar field of Brans-Dicke type. 11 refs.
Beyond Einstein: scientific goals and missions
NASA Astrophysics Data System (ADS)
White, Nicholas E.
A century ago, Albert Einstein began creating his theory of relativity, the ideas we use to understand space, time, and gravity, and he took some of the first steps towards the theory of quantum mechanics, the ideas we use to understand matter and energy. Time magazine named Einstein the “Person of the Century” because his ideas transformed civilization. But his work is not finished: spacetime is not yet reconciled with the quantum. Einstein’s general theory of relativity opened possibilities for the formation and structure of the Universe that seemed unbelievable even to Einstein himself but which have all been subsequently confirmed: that the whole Universe began in a hot, dense Big Bang from which all of space expanded; that dense matter could tie spacetime into tangled knots called black holes; and that “empty” space might contain energy with repulsive gravity. Despite these discoveries, we still do not understand conditions at the beginning of the Universe, how space and time behave at the edge of a black hole, or why distant galaxies are accelerating away from us. These phenomena represent the most extreme interactions of matter and energy with space and time. They are the places to look for clues to the next fundamental revolution in understanding - Beyond Einstein.
NASA Astrophysics Data System (ADS)
Heilbron, John
2005-03-01
As an editor of the Annalen der Physik, Max Planck published Einstein's early papers on thermodynamics and on special relativity, which Planck probably was the first major physicist to appreciate. They respected one another not only as physicists but also, for their inspired creation of world pictures, as artists. Planck helped to establish Einstein in a sinecure at the center of German physics, Berlin. Despite their differences in scientific style, social life, politics, and religion, they became fast friends. Their mutual admiration survived World War I, during which Einstein advocated pacifism and Planck signed the infamous Manifesto of the 93 Intellectuals supporting the German invasion of Belgium. It also survived the Weimar Republic, which Einstein favored and Planck disliked. Physics drew them together, as both opposed the Copenhagen Interpretation; so did common decency, as Planck helped to protect Einstein from anti-semitic attacks. Their friendship did not survive the Nazis. As a standing secretary of the Berlin Academy, Planck had to advise Einstein to resign from it before his colleagues, outraged at his criticism of the new Germany from the safety of California, expelled him. Einstein never forgave his old friend and former fellow artist for not protesting publicly against his expulsion and denigration, and other enormities of National Socialism. .
NASA Astrophysics Data System (ADS)
Erwin, Charlotte
2005-03-01
Albert Einstein traveled to America by boat during the great depression to consult with scientists at the California Institute of Technology. He was a theoretical physicist, a Nobel Prize winner, and a 20th century folk hero. Few members of the general public understood his theories, but they idolized him all the same. The invitation came from physicist Robert Millikan, who had initiated a visiting-scholars program at Caltech shortly after he became head of the school in 1921. Einstein's visits to the campus in 1931, 1932, and 1933 capped Millikan's campaign to make Caltech one of the physics capitals of the world. Mount Wilson astronomer Edwin Hubble's discovery that redshifts are proportional to their distances from the observer challenged Einstein's cosmological picture of a static universe. The big question at Caltech in 1931 was whether Einstein would give up his cosmological constant and accept the idea of an expanding universe. By day, Einstein discussed his theory and its interpretation at length with Richard Tolman, Hubble, and the other scientists on the campus. By night, Einstein filled his travel diary with his personal impressions. During his third visit, Einstein sidestepped as long as possible the question of whether conditions in Germany might prevent his return there. After the January 30 announcement that Hitler had become chancellor of Germany, the question could no longer be evaded. He postponed his return trip for a few weeks and then went to Belgium for several months instead of to Berlin. In the fall of 1933, Albert Einstein returned to the United States as an emigre and became a charter member of Abraham Flexner's new Institute for Advanced Study in Princeton, New Jersey. Why did Einstein go to Princeton and not Pasadena?
Albert Einstein:. Opportunity and Perception
NASA Astrophysics Data System (ADS)
Yang, Chen Ning
2013-05-01
The year 1905 has been called Albert Einstein's "Annus Mirabilis." It was during that year that he caused revolutionary changes in man's primordial concepts about the physical world: space, time, energy, light and matter. How could a 26-year-old clerk, previously unknown, cause such profound conceptual changes, and thereby open the door to the era of modern scientific technological world? No one, of course, can answer that question. But one can, perhaps, analyze some factors that were essential to his stepping into such a historic role...
NASA Astrophysics Data System (ADS)
Rigden, John
2005-05-01
From March 17 to September 29, 1905, just over six months, Einstein wrote five papers that shifted the tectonic foundations of physics and changed the face of Nature. Three of these papers, the March paper presenting the particle of light, the May paper on Brownian motion, and the June paper on the Special Theory of Relativity are universally recognized as fundamental; however, the Brownian motion paper cannot be divorced from Einstein's April paper, A New Determination of the Dimensions of Molecules, and the September paper that gave the world its most famous equation, E = mc^2, cannot be separated from the June paper. These five papers reveal characteristics of Einstein's approach to physics.
Einstein: A Historical Perspective
NASA Astrophysics Data System (ADS)
Kormos-Buchwald, Diana
2015-04-01
In late 1915, Albert Einstein (1879-1955) completed as series of papers on a generalized theory of gravitation that were to constitute a major conceptual change in the history of modern physics and the crowning achievement of his scientific career. But this accomplishment came after a decade of intense intellectual struggle and was received with muted enthusiasm. Einstein's previously unpublished writings and massive correspondence, edited by the Einstein Papers Project, provide vivid insights into the historical, personal, and scientific context of the formulation, completion, and reception of GR during the first decades of the 20th century.
NASA Astrophysics Data System (ADS)
Nishino, Hitoshi; Rajpoot, Subhash
2016-05-01
We present electric-magnetic (EM)-duality formulations for non-Abelian gauge groups with N =1 supersymmetry in D =3 +3 and 5 +5 space-time dimensions. We show that these systems generate self-dual N =1 supersymmetric Yang-Mills (SDSYM) theory in D =2 +2 . For a N =2 supersymmetric EM-dual system in D =3 +3 , we have the Yang-Mills multiplet (Aμ I,λA I) and a Hodge-dual multiplet (Bμν ρ I,χA I) , with an auxiliary tensors Cμν ρ σ I and Kμ ν. Here, I is the adjoint index, while A is for the doublet of S p (1 ). The EM-duality conditions are Fμν I=(1 /4 !)ɛμν ρ σ τ λGρσ τ λ I with its superpartner duality condition λA I=-χA I . Upon appropriate dimensional reduction, this system generates SDSYM in D =2 +2 . This system is further generalized to D =5 +5 with the EM-duality condition Fμν I=(1 /8 !)ɛμν ρ1⋯ρ8Gρ1⋯ρ8 I with its superpartner condition λI=-χI . Upon appropriate dimensional reduction, this theory also generates SDSYM in D =2 +2 . As long as we maintain Lorentz covariance, D =5 +5 dimensions seems to be the maximal space-time dimensions that generate SDSYM in D =2 +2 . Namely, EM-dual system in D =5 +5 serves as the Master Theory of all supersymmetric integrable models in dimensions 1 ≤D ≤3 .
ERIC Educational Resources Information Center
Elliot, Ian
1996-01-01
Describes "Einstein's Adventurarium," a science center housed in an empty shopping mall in Gillette, Wyoming, created through school, business, and city-county government partnership. Describes how interactive exhibits allow exploration of life sciences, physics, and paleontology. (KDFB)
Hypermass generalization of Einstein's gravitation theory
NASA Technical Reports Server (NTRS)
Edmonds, J. D., Jr.
1973-01-01
The curvilinear invariant quaternion formalism is examined for curved space time. Einstein's gravitation equation is shown to have a simple and natural form in this notation. The hypermass generalization of particle mass, which was generated in our studies of the Dirac equation, is incorporated in gravitation by generalizing Einstein's equation. Covariance requires that the gravitational constant be generalized to an invariant quaternion when the mass is. The modification appears minor and of no importance cosmologically, unless one begins considering time and mass dependence of G.
Einstein equation at singularities
NASA Astrophysics Data System (ADS)
Stoica, Ovidiu-Cristinel
2014-02-01
Einstein's equation is rewritten in an equivalent form, which remains valid at the singularities in some major cases. These cases include the Schwarzschild singularity, the Friedmann-Lemaître-Robertson-Walker Big Bang singularity, isotropic singularities, and a class of warped product singularities. This equation is constructed in terms of the Ricci part of the Riemann curvature (as the Kulkarni-Nomizu product between Einstein's equation and the metric tensor).
NASA Astrophysics Data System (ADS)
2010-02-01
NASA has announced the selection of the 2010 Einstein Fellows who will conduct research related to NASA's Physics of the Cosmos program, which aims to expand our knowledge of the origin, evolution, and fate of the Universe. The Einstein Fellowship provides support to the awardees for three years, and the Fellows may pursue their research at a host university or research center of their choosing in the United States. The new Fellows will begin their programs in the fall of 2010. The new Einstein Fellows and their host institutions are listed below: * Simona Giacintucci (Smithsonian Astrophysical Observatory, Cambridge, Mass.) * Boaz Katz (Institute for Advanced Studies, Princeton, N.J.) * Matthew Kerr (Stanford University, Palo Alto, Calif.) * Matthew Kistler (California Institute of Technology, Pasadena) * Emily Levesque (University of Colorado, Boulder) * Xin Liu (Harvard, Cambridge, Mass.) * Tony Mroczkowski (University of Pennsylvania, Philadelphia) * Ryan O'Leary (University of California at Berkeley) * Dov Poznanski (Lawrence Berkeley National Laboratory. Berkeley, Calif.) * Nicolas Yunes (Massachusetts Institute of Technology, Cambridge, Mass.) The Einstein Fellowships are administered for NASA by the Chandra X-ray Center in Cambridge, Mass. Along with the Hubble and Sagan Fellowships, the Einstein Fellowships are made possible by the Astrophysics Division within NASA's Science Mission Directorate. More information on the Einstein Fellowships can be found at: http://cxc.harvard.edu/fellows/CfPfellow.2009.html
NASA Astrophysics Data System (ADS)
Balashov, Yuri; Vizgin, Vladimir
This volume presents a selection of the best contributions by Russian scholars - historians and philosophers of science - to the Einstein Studies industry, broadly construed. Many of the papers were first published in Russian, in the Einshteinovskiy Sbornik series (Einstein Studies) initiated by I. Tamm in 1966. This book explores the historical and foundational issues in general relativity and relativistic cosmology, Einstein's contributions to quantum theory of radiation, and the rise of Dirac's quantum electrodynamics. It also includes a detailed description of the physics colloquium Einstein established and coordinated in 1912- 1914 in Zürich. The contributors draw extensively on documentation previously unavailable to most scholars. Materials from various Russian archives shed new light on the famous exchange (regarding the first evolutionary cosmological models) between Einstein and Alexander Friedmann in the early 1920's and on the role of Boris Podolsky and Vladimir Fock in the emergence of quantum electrodynamics. The little-known correspondence between Einstein and a famous German pilot Paul Erhardt suggests that during World War I, the former was involved with aero- and hydrodynamics research and ways of improving airplane design. Other articles introduce new approaches to important foundational questions in general relativity and cosmology. Historians, philosophers, and sociologists of science will find much new and unexpected material in this engaging volume presenting the best of recent Russian scholarship in the field. The book is also very accessible to the general reader.
Bose-Einstein condensation in microgravity.
van Zoest, T; Gaaloul, N; Singh, Y; Ahlers, H; Herr, W; Seidel, S T; Ertmer, W; Rasel, E; Eckart, M; Kajari, E; Arnold, S; Nandi, G; Schleich, W P; Walser, R; Vogel, A; Sengstock, K; Bongs, K; Lewoczko-Adamczyk, W; Schiemangk, M; Schuldt, T; Peters, A; Könemann, T; Müntinga, H; Lämmerzahl, C; Dittus, H; Steinmetz, T; Hänsch, T W; Reichel, J
2010-06-18
Albert Einstein's insight that it is impossible to distinguish a local experiment in a "freely falling elevator" from one in free space led to the development of the theory of general relativity. The wave nature of matter manifests itself in a striking way in Bose-Einstein condensates, where millions of atoms lose their identity and can be described by a single macroscopic wave function. We combine these two topics and report the preparation and observation of a Bose-Einstein condensate during free fall in a 146-meter-tall evacuated drop tower. During the expansion over 1 second, the atoms form a giant coherent matter wave that is delocalized on a millimeter scale, which represents a promising source for matter-wave interferometry to test the universality of free fall with quantum matter.
Bose-Einstein condensation in microgravity.
van Zoest, T; Gaaloul, N; Singh, Y; Ahlers, H; Herr, W; Seidel, S T; Ertmer, W; Rasel, E; Eckart, M; Kajari, E; Arnold, S; Nandi, G; Schleich, W P; Walser, R; Vogel, A; Sengstock, K; Bongs, K; Lewoczko-Adamczyk, W; Schiemangk, M; Schuldt, T; Peters, A; Könemann, T; Müntinga, H; Lämmerzahl, C; Dittus, H; Steinmetz, T; Hänsch, T W; Reichel, J
2010-06-18
Albert Einstein's insight that it is impossible to distinguish a local experiment in a "freely falling elevator" from one in free space led to the development of the theory of general relativity. The wave nature of matter manifests itself in a striking way in Bose-Einstein condensates, where millions of atoms lose their identity and can be described by a single macroscopic wave function. We combine these two topics and report the preparation and observation of a Bose-Einstein condensate during free fall in a 146-meter-tall evacuated drop tower. During the expansion over 1 second, the atoms form a giant coherent matter wave that is delocalized on a millimeter scale, which represents a promising source for matter-wave interferometry to test the universality of free fall with quantum matter. PMID:20558713
NASA Astrophysics Data System (ADS)
Schemmel, Matthias
In contrast to most of his collegues in astronomy and physics, the German astronomer Karl Schwarzschild immediately recognized the significance of general relativity for physics and astronomy, and played a pioneering role in its early development. In this contribution, it is argued that the clue for understanding Schwarzschild's exceptional reaction to general relativity lies in the study of his prerelativistic work. Long before the rise of general relativity, Schwarzschild occupied himself with foundational problems on the borderline of physics, astronomy, and mathematics that, from today's perspective, belong to the field of problems of that theory. In this contribution, the example of Schwarzschild's early speculations about the non-Euclidean nature of physical space on cosmological scales is presented and their reflection in his reception of general relativity is discussed.
Conversations With Albert Einstein. II
ERIC Educational Resources Information Center
Shankland, R. S.
1973-01-01
Discusses Einstein's views on the role of Michelson-Morley, Fizeau, and Miller experiments in the development of relativity and his attitude toward the theories of new quantum mechanics. Indicates that Einstein's opposition to quantum mechanics is beyond dispute. (CC)
NASA Astrophysics Data System (ADS)
Lindner, R. P.
2002-12-01
Wallace Campbell's later Lick Observatory solar eclipse expeditions included observations intended to test Albert Einstein's predicted bending of starlight passing near the sun. Heber D. Curtis, who had written about Einstein's theory of special relativity already before World War I, spent a great deal of time and effort measuring one set of plates, but he became director of Allegheny Observatory before satisfactorily completing the work. For the rest of his career, Curtis was part of the ``reception" of general relativity in the U.S., and for some years he taught the theory to graduate students. Curtis never accepted the theory and argued against it with students and colleagues, in seminars, meetings, and in print. His arguments are fascinating in terms of Curtis's desire to master the theoretical arguments, disturbing in personal terms. Here I examine the development of Curtis's views and his influence against the background of Einstein's success among the younger generation of astronomers and in the community of midwestern physicists.
Gravitational Lensing: Einstein's unfinished symphony
NASA Astrophysics Data System (ADS)
Treu, Tommaso; Ellis, Richard S.
2015-01-01
Gravitational lensing - the deflection of light rays by gravitating matter - has become a major tool in the armoury of the modern cosmologist. Proposed nearly a hundred years ago as a key feature of Einstein's theory of general relativity, we trace the historical development since its verification at a solar eclipse in 1919. Einstein was apparently cautious about its practical utility and the subject lay dormant observationally for nearly 60 years. Nonetheless there has been rapid progress over the past twenty years. The technique allows astronomers to chart the distribution of dark matter on large and small scales thereby testing predictions of the standard cosmological model which assumes dark matter comprises a massive weakly-interacting particle. By measuring the distances and tracing the growth of dark matter structure over cosmic time, gravitational lensing also holds great promise in determining whether the dark energy, postulated to explain the accelerated cosmic expansion, is a vacuum energy density or a failure of general relativity on large scales. We illustrate the wide range of applications which harness the power of gravitational lensing, from searches for the earliest galaxies magnified by massive clusters to those for extrasolar planets which temporarily brighten a background star. We summarise the future prospects with dedicated ground and space-based facilities designed to exploit this remarkable physical phenomenon.
NASA Astrophysics Data System (ADS)
2011-03-01
ASA has announced the selection of the 2011 Einstein Fellows who will conduct research related to NASA's Physics of the Cosmos program, which aims to expand our knowledge of the origin, evolution, and fate of the Universe. The Einstein Fellowship provides support to the awardees for three years, and the Fellows may pursue their research at a host university or research center of their choosing in the United States. The new Fellows will begin their programs in the fall of 2011. The new Einstein Fellows and their host institutions are listed below: * Akos Bogdan (Smithsonian Astrophysical Observatory, Cambridge, Mass.) * Samuel Gralla (University of Maryland, College Park, Md.) * Philip Hopkins (University of California at Berkeley) * Matthew Kunz (Princeton University, Princeton, N.J.) * Laura Lopez (Massachusetts Institute of Technology, Cambridge, Mass.) * Amy Reines (National Radio Astronomy Observatory, Charlottesville, Virg.) * Rubens Reis (University of Michigan, Ann Arbor) * Ken Shen (Lawrence Berkeley National Laboratory, Berkeley, Calif.) * Jennifer Siegal-Gaskins (California Institute of Technology, Pasadena) * Lorenzo Sironi (Harvard University, Cambridge, Mass.) NASA has two other astrophysics theme-based fellowship programs: the Sagan Fellowship Program, which supports research into exoplanet exploration, and the Hubble Fellowship Program, which supports research into cosmic origins. More information on the Einstein Fellowships can be found at: http://cxc.harvard.edu/fellows/
Examining the Enigmatic Einstein
ERIC Educational Resources Information Center
Khoon, Koh Aik
2007-01-01
Albert Einstein is the icon of scientific genius. His is one the most recognizable faces in the history of mankind. This paper takes a cursory look at the man who is commonly perceived to be the epitome of eccentricity. We manage to sum up his salient traits which are associated with his name. The traits are based on anecdotal evidence. This…
NASA Astrophysics Data System (ADS)
Löffler, Frank
2012-03-01
The Einstein Toolkit Consortium is developing and supporting open software for relativistic astrophysics. Its aim is to provide the core computational tools that can enable new science, broaden our community, facilitate interdisciplinary research and take advantage of petascale computers and advanced cyberinfrastructure. The Einstein Toolkit currently consists of an open set of over 100 modules for the Cactus framework, primarily for computational relativity along with associated tools for simulation management and visualization. The toolkit includes solvers for vacuum spacetimes as well as relativistic magneto-hydrodynamics, along with modules for initial data, analysis and computational infrastructure. These modules have been developed and improved over many years by many different researchers. The Einstein Toolkit is supported by a distributed model, combining core support of software, tools, and documentation in its own repositories and through partnerships with other developers who contribute open software and coordinate together on development. As of January 2012 it has 68 registered members from 30 research groups world-wide. This talk will present the current capabilities of the Einstein Toolkit and will point to information how to leverage it for future research.
Albert Einstein - Chief Engineer of the Universe: 100 Authors for Einstein Essays
NASA Astrophysics Data System (ADS)
Renn, Jürgen
2005-09-01
In 1905, Albert Einstein published five scientific articles that fundamentally changed the world-view of physics: The Special Theory of Reativity revolutionized our concept of space and time, E=mcÂ² became the best-known equation in physics. On the occasion of the 100th aniversary of his "annus mirabilis" 1905, the UNESCO declared the year 2005 the "World Year of Physics", in order to draw attention to the impact of physics. The Max Planck Institute for the history of science dedicates an exhibition in the Kronprinzenpalais in Berlin to the probably most important scientist of the 20th century. In this book, 100 authors explain the historical background of Einstein's life and work, shed light on many different aspects of his biography, and on the scientific fields and topics that are connected to Einstein's work. The authors are some of the most renowned Einstein researchers in the world, such as Jürgen Ehlers, Peter Galison, Zeev Rosenkranz, John Stachel and Robert Schulmann. The essays form a bridge between scientific and cultural history, opening up a perspective on Einstein's biography which goes beyond the traditional picture of the exceptional science genius.
Symmetries of the 4D self-dual Yang-Mills equation and the reduction to the 2D KdV equation
HoSeong La )
1992-04-01
The Lie-point and the Lie-Baecklund symmetries of 4D self-dual Yang-Mills equation are investigated as those of differential equations. The Lie-point symmetry is nothing but the gauge symmetry at the level of field equation, but the Lie-Baecklund symmetries are new. In particular, by the symmetry reduction to KdV equation in 2D the corresponding Lie-Baecklund symmetries which reduce to the isospectral symmetries or to the nonisospectral symmetries are identified. Some speculations on the existence of the self-dual Yang-Mills hierarchy as well as the derivation of the 4D analogue of the string equation of the nonperturbative 2D quantum gravity are given.
Treska, V
2003-02-01
Untreated rupture of an aneurysm of the abdominal aorta is fatal in almost 100% of the patients. In the majority of cases the assessment of a correct, early diagnosis is simple (hypotension, backache, abdominal pain, pulsating resistance in the abdomen) and makes a prompt surgical or endovascular operation possible. In some instances however rupture of aneurysms of the abdominal aorta simulates other clinical conditions (acute cholecystitis, acute diverculitis of the sigmoid) which may delay the correct diagnosis and reduce the patient's chance of survival. The author describes, based on historical documents, the treacherous course of the disease in the scientific genius Albert Einstein where rupture of an aneurysm simulated acute cholecystitis, and in the world literature this symptomatology was subsequently described as Einstein's sign.
Einstein's Real "biggest Blunder"
NASA Astrophysics Data System (ADS)
Ellis, Homer G.
2012-10-01
Albert Einstein's real "biggest blunder" was not the 1917 introduction into his gravitational field equations of a cosmological constant term Λ, rather was his failure in 1916 to distinguish between the entirely different concepts of active gravitational mass and passive gravitational mass. Had he made the distinction, and followed David Hilbert's lead in deriving field equations from a variational principle, he might have discovered a true (not a cut and paste) Einstein-Rosen bridge and a cosmological model that would have allowed him to predict, long before such phenomena were imagined by others, inflation, a big bounce (not a big bang), an accelerating expansion of the universe, dark matter, and the existence of cosmic voids, walls, filaments and nodes.
Einstein and a century of time
NASA Astrophysics Data System (ADS)
Raine, D. J.
2005-09-01
In a world overabundant in information, a subject is defined by its iconography. Physics is the falling apple, the planetary atom, the laser, the mushroom cloud and the image of the later Einstein - images that represent, respectively, gravity, atomic theory, quantum theory, mass-energy and the scientist who had a hand in all four. It is therefore appropriate that World Year of Physics is called Einstein Year in the UK. Of course one can argue that progress in science depends on the contributions of many people; that there are other geniuses in physics, even some colourful personalities. Nevertheless there are fundamental reasons why Einstein's early achievements stand out even in their company. When at last the thought came to him that 'time itself was suspect', Einstein had found a new insight into the nature of the physical universe. It is this: that the universal properties of material objects tell us about the nature of space and time, and it is through these properties, not philosophical logic or common sense, that we discover the structure of spacetime. The later Einstein turned this successful formula on its head and sought to use the properties of spacetime to define those of material objects, thereby seeking to abolish matter entirely in favour of geometry. Before I introduce this special feature of European Journal of Physics I will say a few words about what is not here. Like all great geniuses Einstein can be seen as the climax of what went before him and the initiation of what was to follow. Looking back we can see the influence of Mach's positivism, according to which the role of science is to relate observations to other observations; hence only observations can tell us what is 'real'. But Einstein also grew up with the family electromechanical businesses, which testifies to the reality of the Maxwellian electromagnetic fields: thus only theory can tell us what is real! As is well known, Einstein himself refused to accept the full consequences of
El-Sherbini, Th.M.
2005-03-17
This article gives a brief review of Bose-Einstein condensation. It is an exotic quantum phenomenon that was observed in dilute atomic gases for the first time in 1995. It exhibits a new state of matter in which a group of atoms behaves as a single particle. Experiments on this form of matter are relevant to many different areas of physics- from atomic clocks and quantum computing to super fluidity, superconductivity and quantum phase transition.
Einstein's Years in Switzerland
NASA Astrophysics Data System (ADS)
Plendl, Hans S.
2005-11-01
Albert Einstein left Germany, the country of his birth, in 1894 and moved to Switzerland in 1895. He studied, worked and taught there, except for a year's stay in Prague, until1914. That year he returned to Germany, where he lived until his emigration to the United States in 1933. In 1905, while living with his wife Mileva and their first son Hans Albert in Bern and working as a technical expert at the Swiss Patent Office, he published his dissertation on the determination of molecular dimensions, his papers on Brownian Motion that helped to establish the Kinetic Theory of Heat and on the Photo-Electric Effect that validated the Quantum Theory of Light, and the two papers introducing the Special Theory of Relativity. How the young Einstein could help to lay the foundations of these theories while still working on his dissertation, holding a full-time job and helping to raise a family has evoked much discussion among his biographers. In this contribution, the extent to which living within Swiss society and culture could have made this feat possible will be examined. Old and recent photos of places in Switzerland where Einstein has lived and worked will be shown.
Einstein's Jury: Trial by Telescope
NASA Astrophysics Data System (ADS)
Crelinsten, Jeffrey
2007-03-01
While Einstein's theory of relativity ultimately laid the foundation for modern studies of the universe, it took a long time to be accepted. Between 1905 and 1930, relativity was poorly understood and Einstein worked hard to try to make it more accessible to scientists and scientifically literate laypeople. Its acceptance was largely due to the astronomy community, which undertook precise measurements to test Einstein's astronomical predictions. The well-known 1919 British eclipse expeditions that made Einstein famous did not convince most scientists to accept relativity. The 1920s saw numerous attempts to measure light-bending, as well as solar line displacements and even ether-drift. How astronomers approached the ``Einstein problem'' in these early years before and after the First World War, and how the public reacted to what they reported, helped to shape attitudes we hold today about Einstein and his ideas.
NASA Astrophysics Data System (ADS)
Modi, Kavan
2008-03-01
Pathologist Thomas Stoltz Harvey performed an autopsy on Einstein after his death in 1955. During the autopsy Harvey removed Einstein's brain, took pictures of it and then cut it into several pieces. A lot of scientific attention has been devoted to Einstein' brain, and it still comes up once in a while. We've all heard something or other about Einstein's brain, as it has become somewhat of a folk lore. What is less known is that Harvey in actuality did not have the permission to remove the brain. Only later Harvey convinced Einstein's Hans Albert Einstein son that this was for a good purpose. The brain would only be used for scientific purpose, which will be published reputable journals. I will try to describe in some detail the long journey this brain has taken in last fifty two years.
NASA Astrophysics Data System (ADS)
Zhang, Yong-Chang; Zhou, Zheng-Wei; Malomed, Boris A.; Pu, Han
2015-12-01
By means of variational methods and systematic numerical analysis, we demonstrate the existence of metastable solitons in three dimensional (3D) free space, in the context of binary atomic condensates combining contact self-attraction and spin-orbit coupling, which can be engineered by available experimental techniques. Depending on the relative strength of the intra- and intercomponent attraction, the stable solitons feature a semivortex or mixed-mode structure. In spite of the fact that the local cubic self-attraction gives rise to the supercritical collapse in 3D, and hence the setting produces no true ground state, the solitons are stable against small perturbations, motion, and collisions.
Zhang, Yong-Chang; Zhou, Zheng-Wei; Malomed, Boris A; Pu, Han
2015-12-18
By means of variational methods and systematic numerical analysis, we demonstrate the existence of metastable solitons in three dimensional (3D) free space, in the context of binary atomic condensates combining contact self-attraction and spin-orbit coupling, which can be engineered by available experimental techniques. Depending on the relative strength of the intra- and intercomponent attraction, the stable solitons feature a semivortex or mixed-mode structure. In spite of the fact that the local cubic self-attraction gives rise to the supercritical collapse in 3D, and hence the setting produces no true ground state, the solitons are stable against small perturbations, motion, and collisions. PMID:26722921
NASA Astrophysics Data System (ADS)
Norton, John D.
2016-08-01
What powered Einstein's discoveries? Was it asking naïve questions, stubbornly? Was it a mischievous urge to break rules? Was it the destructive power of operational thinking? It was none of these. Rather, Einstein made his discoveries through lengthy, mundane investigations, pursued with tenacity and discipline. We have been led to think otherwise in part through Einstein's brilliance at recounting in beguilingly simple terms a few brief moments of transcendent insight, and in part through our need to find a simple trick underlying his achievements. These ideas are illustrated with the examples of Einstein's 1905 discoveries of special relativity and the light quantum.
NASA Astrophysics Data System (ADS)
Stachel, John
Einstein from 'B' to 'Z' is a unique collection of 37 published and unpublished papers on Albert Einstein that have been written by John Stachel, a physicist and historian of science. Stachel has written about Einstein - the man, his philosophy, and his work - for more than 40 years. The articles included in this volume will present a coherent picture of the new view of Einstein which is emerging from recent detailed documentation and studies of activities and work during Einstein's formative years about which so many old and new myths abound. Stachel's special introduction to the collection will explicitly tie together the themes implicit in the papers. This work will be of particular interest to historians of 20th century science, students and practitioners of physics, and the apparently large section of the general reading public that continues to be fascinated with Einstein. It will serve as an excellent reference text. The essays are grouped thematically into the following areas: 1. The human side. 2. Editing the Einstein papers. 3. Surveys of Einstein's work. 4. Special relativity. 5. General relativity. 6. Quantum theory. 7. Einstein and others. 8. Book reviews.
NASA Astrophysics Data System (ADS)
Norton, John D.
2016-09-01
What powered Einstein's discoveries? Was it asking naïve questions, stubbornly? Was it a mischievous urge to break rules? Was it the destructive power of operational thinking? It was none of these. Rather, Einstein made his discoveries through lengthy, mundane investigations, pursued with tenacity and discipline. We have been led to think otherwise in part through Einstein's brilliance at recounting in beguilingly simple terms a few brief moments of transcendent insight, and in part through our need to find a simple trick underlying his achievements. These ideas are illustrated with the examples of Einstein's 1905 discoveries of special relativity and the light quantum.
Bose-Einstein Condensation in Microgravity
NASA Astrophysics Data System (ADS)
van Zoest, T.; Gaaloul, N.; Singh, Y.; Ahlers, H.; Herr, W.; Seidel, S. T.; Ertmer, W.; Rasel, E.; Eckart, M.; Kajari, E.; Arnold, S.; Nandi, G.; Schleich, W. P.; Walser, R.; Vogel, A.; Sengstock, K.; Bongs, K.; Lewoczko-Adamczyk, W.; Schiemangk, M.; Schuldt, T.; Peters, A.; Könemann, T.; Müntinga, H.; Lämmerzahl, C.; Dittus, H.; Steinmetz, T.; Hänsch, T. W.; Reichel, J.
2010-06-01
Albert Einstein’s insight that it is impossible to distinguish a local experiment in a “freely falling elevator” from one in free space led to the development of the theory of general relativity. The wave nature of matter manifests itself in a striking way in Bose-Einstein condensates, where millions of atoms lose their identity and can be described by a single macroscopic wave function. We combine these two topics and report the preparation and observation of a Bose-Einstein condensate during free fall in a 146-meter-tall evacuated drop tower. During the expansion over 1 second, the atoms form a giant coherent matter wave that is delocalized on a millimeter scale, which represents a promising source for matter-wave interferometry to test the universality of free fall with quantum matter.
NASA Astrophysics Data System (ADS)
Grundmann, Siegfried
In 1919 the Prussian Ministry of Science, Arts and Culture opened a dossier on "Einstein's Theory of Relativity." It was rediscovered by the author in 1961 and is used in conjunction with numerous other subsequently identified 'Einstein' files as the basis of this fascinating book. In particular, the author carefully scrutinizes Einstein's FBI file from 1950-55 against mostly unpublished material from European including Soviet sources and presents hitherto unknown documentation on Einstein's alleged contacts with the German Communist Party and the Comintern.
de Sitter group and Einstein-Hilbert Lagrangian
Mahato, Prasanta
2004-12-15
Axial-vector torsion in the Einstein-Cartan space U{sub 4} is considered here. By picking a particular term from the SO(4,1) Pontryagin density and then modifying it in a SO(3,1) invariant way, we get a Lagrangian density with Lagrange multipliers. Then considering torsion and torsionless connection as independent fields, it has been found that {kappa} and {lambda} of Einstein-Hilbert Lagrangian, appear as integration constants in such a way that {kappa} has been found to be linked with the topological Nieh-Yan density of U{sub 4} space.
Einstein and a century of time
NASA Astrophysics Data System (ADS)
Raine, D. J.
2005-09-01
In a world overabundant in information, a subject is defined by its iconography. Physics is the falling apple, the planetary atom, the laser, the mushroom cloud and the image of the later Einstein - images that represent, respectively, gravity, atomic theory, quantum theory, mass-energy and the scientist who had a hand in all four. It is therefore appropriate that World Year of Physics is called Einstein Year in the UK. Of course one can argue that progress in science depends on the contributions of many people; that there are other geniuses in physics, even some colourful personalities. Nevertheless there are fundamental reasons why Einstein's early achievements stand out even in their company. When at last the thought came to him that 'time itself was suspect', Einstein had found a new insight into the nature of the physical universe. It is this: that the universal properties of material objects tell us about the nature of space and time, and it is through these properties, not philosophical logic or common sense, that we discover the structure of spacetime. The later Einstein turned this successful formula on its head and sought to use the properties of spacetime to define those of material objects, thereby seeking to abolish matter entirely in favour of geometry. Before I introduce this special feature of European Journal of Physics I will say a few words about what is not here. Like all great geniuses Einstein can be seen as the climax of what went before him and the initiation of what was to follow. Looking back we can see the influence of Mach's positivism, according to which the role of science is to relate observations to other observations; hence only observations can tell us what is 'real'. But Einstein also grew up with the family electromechanical businesses, which testifies to the reality of the Maxwellian electromagnetic fields: thus only theory can tell us what is real! As is well known, Einstein himself refused to accept the full consequences of
ERIC Educational Resources Information Center
Physics Today, 1979
1979-01-01
Celebrates the centennial of Einstein's birth with an eight-page pictorial biography and two special articles: (1) Einstein the catalyst; and (2) Unitary field theories. His special and general theories of relativity and his contributions to quantum physics and other topics are also presented. (HM)
Einstein Inflationary Probe (EIP)
NASA Technical Reports Server (NTRS)
Hinshaw, Gary
2004-01-01
I will discuss plans to develop a concept for the Einstein Inflation Probe: a mission to detect gravity waves from inflation via the unique signature they impart to the cosmic microwave background (CMB) polarization. A sensitive CMB polarization satellite may be the only way to probe physics at the grand-unified theory (GUT) scale, exceeding by 12 orders of magnitude the energies studied at the Large Hadron Collider. A detection of gravity waves would represent a remarkable confirmation of the inflationary paradigm and set the energy scale at which inflation occurred when the universe was a fraction of a second old. Even a strong upper limit to the gravity wave amplitude would be significant, ruling out many common models of inflation, and pointing to inflation occurring at much lower energy, if at all. Measuring gravity waves via the CMB polarization will be challenging. We will undertake a comprehensive study to identify the critical scientific requirements for the mission and their derived instrumental performance requirements. At the core of the study will be an assessment of what is scientifically and experimentally optimal within the scope and purpose of the Einstein Inflation Probe.
Einstein, Entropy and Anomalies
NASA Astrophysics Data System (ADS)
Sirtes, Daniel; Oberheim, Eric
2006-11-01
This paper strengthens and defends the pluralistic implications of Einstein's successful, quantitative predictions of Brownian motion for a philosophical dispute about the nature of scientific advance that began between two prominent philosophers of science in the second half of the twentieth century (Thomas Kuhn and Paul Feyerabend). Kuhn promoted a monistic phase-model of scientific advance, according to which a paradigm driven `normal science' gives rise to its own anomalies, which then lead to a crisis and eventually a scientific revolution. Feyerabend stressed the importance of pluralism for scientific progress. He rejected Kuhn's model arguing that it fails to recognize the role that alternative theories can play in identifying exactly which phenomena are anomalous in the first place. On Feyerabend's account, Einstein's predictions allow for a crucial experiment between two incommensurable theories, and are an example of an anomaly that could refute the reigning paradigm only after the development of a competitor. Using Kuhn's specification of a disciplinary matrix to illustrate the incommensurability between the two paradigms, we examine the different research strategies available in this peculiar case. On the basis of our reconstruction, we conclude by rebutting some critics of Feyerabend's argument.
Quantum Deformations of Einstein's Relativistic Symmetries
Lukierski, Jerzy
2006-11-03
We shall outline two ways of introducing the modification of Einstein's relativistic symmetries of special relativity theory -- the Poincare symmetries. The most complete way of introducing the modifications is via the noncocommutative Hopf-algebraic structure describing quantum symmetries. Two types of quantum relativistic symmetries are described, one with constant commutator of quantum Minkowski space coordinates ({theta}{mu}{nu}-deformation) and second with Lie-algebraic structure of quantum space-time, introducing so-called {kappa}-deformation. The third fundamental constant of Nature - fundamental mass {kappa} or length {lambda} - appears naturally in proposed quantum relativistic symmetry scheme. The deformed Minkowski space is described as the representation space (Hopf-module) of deformed Poincare algebra. Some possible perspectives of quantum-deformed relativistic symmetries will be outlined.
Finding solutions to the Einstein equations
NASA Astrophysics Data System (ADS)
Millward, Robert Steven
2004-07-01
This dissertation is a description of a variety of methods of solving the Einstein equations describing the gravitational interaction in different mathematical and astrophysical settings. We begin by discussing a numerical study of the Einstein-Yang-Mills-Higgs system in spherical symmetry. The equations are presented along with boundary and initial conditions. An explanation of the numerical scheme is then given. This is followed by a discussion of the solutions obtained together with an interpretation in the context of gravitational collapse and critical phenomena at the threshold of black hole formation. Following this, we generalize the same system to axisymmetry. The full, gravitational equations are presented along with a short discussion of the problems we encountered in trying to solve these. As a first step we consider evolving the matter fields in flat space. The simplified equations are given and the numerical scheme implemented to solve them discussed. We then consider some analytic techniques to understanding the Einstein equations and the gravitating systems they should describe. One such is to change the spacetime dimension. This we do in considering magnetic solutions to the (2 + 1) Einstein-Maxwell-Dilaton system with nonzero cosmological constant. The solutions are investigated to determine whether these correspond to “soliton”-like solutions or black holes. As another example of this general approach, we introduce an extra timelike coordinate into the spherically symmetric vacuum system, and attempt to find a solution comparing the result to the more well known Schwarzschild solution. Finally, we give a short description of some preliminary work which will combine some of these numerical and analytical techniques. This approach simply takes the matter fields as weak and propagates them on a fixed spacetime background. In our particular case, we intend to study the evolution of Maxwell fields in the Schwarzschild geometry. We provide
Diquark Bose-Einstein condensation
Nawa, K.; Nakano, E.; Yabu, H.
2006-08-01
Bose-Einstein condensation of composite diquarks in quark matter (the color superconductor phase) is discussed using the quasichemical equilibrium theory at a relatively low-density region near the deconfinement phase transition, where dynamical quark-pair fluctuations are assumed to be described as bosonic degrees of freedom (diquarks). A general formulation is given for the diquark formation and particle-antiparticle pair-creation processes in the relativistic framework, and some interesting properties are shown, which are characteristic for the relativistic many-body system. Behaviors of transition temperature and phase diagram of the quark-diquark matter are generally presented in model parameter space, and their asymptotic behaviors are also discussed. As an application to the color superconductivity, the transition temperatures and the quark and diquark density profiles are calculated in case with constituent/current quarks, where the diquark is in the bound/resonant state. We obtained T{sub C}{approx}60-80 MeV for constituent quarks and T{sub C}{approx}130 MeV for current quarks at a moderate density ({rho}{sub b}{approx}3{rho}{sub 0}). The method is also developed to include interdiquark interactions into the quasichemical equilibrium theory within a mean-field approximation, and it is found that a possible repulsive diquark-diquark interaction lowers the transition temperature by {approx}50%.
Beyond Einstein: From the Big Bang to Black Holes
NASA Technical Reports Server (NTRS)
2005-01-01
How did the Universe begin? Does time have a beginning and an end? Does space have edges? The questions are clear and simple. They are as old as human curiosity. But the answers have always seemed beyond the reach of science. Until now. In their attempts to understand how space, time, and matter are connected, Einstein and his successors made three predictions. First, space is expanding from a Big Bang; second, space and time can tie themselves into contorted knots called black holes where time actually comes to a halt; third, space itself contains some kind of energy that is pull- ing the Universe apart. Each of these three predictions seemed so fantastic when it was made that everyone, including Einstein himself, regarded them as unlikely. Incredibly, all three have turned out to be true. Yet Einstein's legacy is one of deep mystery, because his theories are silent on three questions raised by his fantastic predictions: (1) What powered the Big Bang? (2) What happens to space, time, and matter at the edge of a black hole? (3) What is the mysterious dark energy pulling the Universe apart? The answers to these questions-which lie at the crux of where our current theories fail us-will lead to a profound, new understanding of the nature of time and space. To find answers, however, we must venture beyond Einstein. The answers require new theories, such as the inflationary Universe and new insights in high-energy particle theory. Like Einstein s theories, these make fantastic predictions that seem hard to believe: unseen dimensions and entire universes beyond our own. We must find facts to confront and guide these new theories. Powerful new technologies now make this possible. And NASA and its partners are developing an armada of space-based observatories to chart the path to discovery. Here is where the Beyond Einstein story begins. By exploring the three questions that are Einstein s legacy, we begin the next revolution in understanding our Universe. We plot our way
Uniqueness and nonuniqueness in the Einstein constraints.
Pfeiffer, Harald P; York, James W
2005-08-26
The conformal thin-sandwich (CTS) equations are a set of four of the Einstein equations, which generalize the Laplace-Poisson equation of Newton's theory. We examine numerically solutions of the CTS equations describing perturbed Minkowski space, and find only one solution. However, we find two distinct solutions, one even containing a black hole, when the lapse is determined by a fifth elliptic equation through specification of the mean curvature. While the relationship of the two systems and their solutions is a fundamental property of general relativity, this fairly simple example of an elliptic system with nonunique solutions is also of broader interest. PMID:16197202
Einstein's Theory Fights off Challengers
NASA Astrophysics Data System (ADS)
2010-04-01
Two new and independent studies have put Einstein's General Theory of Relativity to the test like never before. These results, made using NASA's Chandra X-ray Observatory, show Einstein's theory is still the best game in town. Each team of scientists took advantage of extensive Chandra observations of galaxy clusters, the largest objects in the Universe bound together by gravity. One result undercuts a rival gravity model to General Relativity, while the other shows that Einstein's theory works over a vast range of times and distances across the cosmos. The first finding significantly weakens a competitor to General Relativity known as "f(R) gravity". "If General Relativity were the heavyweight boxing champion, this other theory was hoping to be the upstart contender," said Fabian Schmidt of the California Institute of Technology in Pasadena, who led the study. "Our work shows that the chances of its upsetting the champ are very slim." In recent years, physicists have turned their attention to competing theories to General Relativity as a possible explanation for the accelerated expansion of the universe. Currently, the most popular explanation for the acceleration is the so-called cosmological constant, which can be understood as energy that exists in empty space. This energy is referred to as dark energy to emphasize that it cannot be directly detected. In the f(R) theory, the cosmic acceleration comes not from an exotic form of energy but from a modification of the gravitational force. The modified force also affects the rate at which small enhancements of matter can grow over the eons to become massive clusters of galaxies, opening up the possibility of a sensitive test of the theory. Schmidt and colleagues used mass estimates of 49 galaxy clusters in the local universe from Chandra observations, and compared them with theoretical model predictions and studies of supernovas, the cosmic microwave background, and the large-scale distribution of galaxies. They
Einstein: The Gourmet of Creativity.
ERIC Educational Resources Information Center
Greenberg, Joel
1979-01-01
Reports a psychiatrist's analysis of Einstein's personal account of how he developed the theory of relativity. The psychiatrist cites Janusian thinking, actively conceiving two or more opposite concepts simultaneously, as a characteristic of much creative thought in general. (MA)
Quantum and thermal fluctuations of trapped Bose-Einstein condensates
Kruglov, V.I.; Collett, M.J.; Olsen, M.K.
2005-09-15
We quantize a semiclassical system defined by the Hamiltonian obtained from the asymptotic self-similar solution of the Gross-Pitaevskii equation for a trapped Bose-Einstein condensate with a linear gain term. On the basis of a Schroedinger equation derived in a space of ellipsoidal parameters, we analytically calculate the quantum mechanical and thermal variance in the ellipsoidal parameters for Bose-Einstein condensates in various shapes of trap. We show that, except for temperatures close to zero, dimensionless dispersions do not depend on the frequencies of the trap and they have the same dependence on dimensionless temperatures.
Einstein, the Universe, and All That: An Introduction to Relativity
NASA Technical Reports Server (NTRS)
Prescod-Weinstein, Chandra
2011-01-01
Black holes) an expanding universe) space and time inextricably tied together) GPS ... What was this Einstein guy thinking?!? In this tutorial) I'll give an overview of Einstein's theories of relativity and the wild things they say about our Universe. What really happens when a particle crosses an event horizon? What is the future of the Universe? And how can we know it? Wh I'll try to touch on these questions and in so doing) give the talks in the Cosmology) Gravitation and Relativity sessions some context.
Euclidean wormhole solutions of Einstein-Yang-Mills theory in diverse dimensions
Yoshida, K.; Hirenzaki, S. ); Shiraishi, K. )
1990-09-15
We solve the Euclidean Einstein equations with non-Abelian gauge fields of sufficiently large symmetry in various dimensions. In higher-dimensional spaces, we find the solutions which are similar to so-called scalar wormholes. In four-dimensional space-time, we find singular wormhole solutions with infinite Euclidean action. Wormhole solutions in the three-dimensional Einstein-Yang-Mills theory with a Chern-Simons term are also constructed.
Implications of Einstein-Weyl Causality on Quantum Mechanics
NASA Astrophysics Data System (ADS)
Bendaniel, David
A fundamental physical principle that has consequences for the topology of space-time is the principle of Einstein-Weyl causality. This also has quantum mechanical manifestations. Borchers and Sen have rigorously investigated the mathematical implications of Einstein-Weyl causality and shown the denumerable space-time Q2 would be implied. They were left with important philosophical paradoxes regarding the nature of the physical real line E, e.g., whether E = R, the real line of mathematics. In order to remove these paradoxes an investigation into a constructible foundation is suggested. We have pursued such a program and find it indeed provides a dense, denumerable space-time and, moreover, an interesting connection with quantum mechanics. We first show that this constructible theory contains polynomial functions which are locally homeomorphic with a dense, denumerable metric space R* and are inherently quantized. Eigenfunctions governing fields can then be effectively obtained by computational iteration. Postulating a Lagrangian for fields in a compactified space-time, we get a general description of which the Schrodinger equation is a special case. From these results we can then also show that this denumerable space-time is relational (in the sense that space is not infinitesimally small if and only if it contains a quantized field) and, since Q2 is imbedded in R*2, it directly fulfills the strict topological requirements for Einstein-Weyl causality. Therefore, the theory predicts that E = R*.
Minimal extension of Einstein's theory: The quartic gravity
NASA Astrophysics Data System (ADS)
Karasu, Atalay; Kenar, Esin; Tekin, Bayram
2016-04-01
We study structure of solutions of the recently constructed minimal extensions of Einstein's gravity in four dimensions at the quartic curvature level. The extended higher derivative theory, just like Einstein's gravity, has only a massless spin-two graviton about its unique maximally symmetric vacuum. The extended theory does not admit the Schwarzschild or Kerr metrics as exact solutions, hence there is no issue of Schwarzschild type singularity but, approximately, outside a source, spherically symmetric metric with the correct Newtonian limit is recovered. We also show that for all Einstein space-times, the square of the Riemann tensor (the Kretschmann scalar or the Gauss-Bonnet invariant) obeys a nonlinear scalar Klein-Gordon equation.
NASA Technical Reports Server (NTRS)
Elvis, Martin; Plummer, David; Schachter, Jonathan; Fabbiano, G.
1992-01-01
A catalog of 819 sources detected in the Einstein IPC Slew Survey of the X-ray sky is presented; 313 of the sources were not previously known as X-ray sources. Typical count rates are 0.1 IPC count/s, roughly equivalent to a flux of 3 x 10 exp -12 ergs/sq cm s. The sources have positional uncertainties of 1.2 arcmin (90 percent confidence) radius, based on a subset of 452 sources identified with previously known pointlike X-ray sources (i.e., extent less than 3 arcmin). Identifications based on a number of existing catalogs of X-ray and optical objects are proposed for 637 of the sources, 78 percent of the survey (within a 3-arcmin error radius) including 133 identifications of new X-ray sources. A public identification data base for the Slew Survey sources will be maintained at CfA, and contributions to this data base are invited.
Breakdown criteria for nonvacuum Einstein equations
NASA Astrophysics Data System (ADS)
Shao, Arick
We generalize a recent "breakdown criterion" result of S. Klainerman and I. Rodnianski, which states roughly that an Einstein vacuum spacetime, given as a CMC foliation, can be extended if the second fundamental form and the derivative of the lapse of the foliation are uniformly bounded. We adapt this theorem and its proof to Einstein-scalar and Einstein-Maxwell spacetimes. In particular, we deal with additional issues resulting from nontrivial Ricci curvature and the coupling between the Einstein and the field equations. The results we prove can be directly extended to Einstein-Klein-Gordon and Einstein-Yang-Mills spacetimes.
Einstein's Radiation Formula and Modifications to the Einstein Equation
NASA Astrophysics Data System (ADS)
Lo, C. Y.
1995-12-01
Einstein's radiation formula is supported by the Taylor-Hulse experiment, but its derivation is not self-consistent. Furthermore, as discovered by Einstein, his radiation formula is not compatible with his field equation. As suggested by Einstein's own remark, modifications to the source tensor are necessary. Based on the Taylor-Hulse experiment, in this paper a theory is developed within the theoretical framework of general relativity within which the radiation formula remains the same for binary stars. Concurrently, it is determined that, because of radiation, the source tensor is not zero in a vacuum. Antigravity coupling, suggested by Pauli as a possibility, is a necessary feature. In addition, it is shown that the current theory of linearized gravity is not valid for radiation.
NASA Astrophysics Data System (ADS)
Romer, Robert H.
2005-03-01
"So you're studying at Princeton. Would you like to meet Einstein?" That question, during a brief two-body collision at a cocktail party, a collision that was over before I could think of an appropriate response, led—over a year later—to one of the more memorable half hours of my life. It was an elastic collision, we drifted apart, and I thought it had simply been a casual remark until a few days later when the mail brought me a carbon copy [sic] of a letter (dated "25.XII.52") from the speaker, Dr. Tilly Edinger, to Albert Einstein. Accompanying the letter to Einstein was a card that Dr. Edinger advised me to send around to Einstein's home on Mercer Street to request a meeting. (What is perhaps most truly astonishing in connection with this event is that not only do I still have that carbon copy—and the eventual letter from Mercer Street that invited me to Einstein's home—but that I was able to find both documents in my attic!)
Einstein Session of the Pontifical Academy.
ERIC Educational Resources Information Center
Science, 1980
1980-01-01
The texts of four speeches, given at the 1979 Einstein Session of the Pontifical Academy held in Rome, are presented. Each address relates to some aspect of the life and times of Albert Einstein. (SA)
NASA Astrophysics Data System (ADS)
Hecht, Eugene
2009-09-01
This paper explores the evolution of Einstein's understanding of mass and energy. Early on, Einstein embraced the idea of a speed-dependent mass but changed his mind in 1906 and thereafter carefully avoided that notion entirely. He shunned, and explicitly rejected, what later came to be known as "relativistic mass." Nonetheless many textbooks and articles credit him with the relation E =mc2, where E is the total energy, m is the relativistic mass, and c is the vacuum speed of light. Einstein never derived this relation, at least not with that understanding of the meaning of its terms. He consistently related the "rest energy" of a system to its invariant inertial mass.
From Petrov-Einstein to Navier-Stokes
NASA Astrophysics Data System (ADS)
Lysov, Vyacheslav
The fluid/gravity correspondence relates solutions of the incompressible Navier-Stokes equation to metrics which solve the Einstein equations. We propose propose two possible approaches to establish this correspondence: perturbative expansion for shear modes and large mean curvature expansion for algebraically special metrics. We show by explicit construction that for every solution of the incompressible Navier-Stokes equation in p+1 dimensions, there is an associated "dual" solution of the vacuum Einstein equations in p+2 dimensions. The dual geometry has an intrinsically flat time-like boundary segment whose extrinsic curvature is given by the stress tensor of the Navier-Stokes fluid. We consider a "near-horizon" limit in which hypersurface becomes highly accelerated. The near-horizon expansion in gravity is shown to be mathematically equivalent to the hydrodynamic expansion in fluid dynamics, and the Einstein equation reduces to the incompressible Navier-Stokes equation. It is shown that imposing a Petrov type I condition on the hypersurface geometry reduces the degrees of freedom in the extrinsic curvature to those of a fluid. Moreover, expanding around a limit in which the mean curvature of the embedding diverges, the leading-order Einstein constraint equations on hypersurface are shown to reduce to the non-linear incompressible Navier-Stokes equation for a fluid moving in hypersurface. We extend the fluid/gravity correspondence to include the magnetohydrodynamics/gravity correspondence, which translates solutions of the equations of magnetohydrodynamics (describing charged fluids) into geometries that satisfy the Einstein-Maxwell equations. We present an explicit example of this new correspondence in the context of flat Minkowski space. We show that a perturbative deformation of the Rindler wedge satisfies the Einstein-Maxwell equations provided that the parameters appearing in the expansion, which we interpret as fluid fields, satisfy the
Einstein for Schools and the General Public
ERIC Educational Resources Information Center
Johansson, K. E.; Kozma, C; Nilsson, Ch
2006-01-01
In April 2005 the World Year of Physics (Einstein Year in the UK and Ireland) was celebrated with an Einstein week in Stockholm House of Science. Seven experiments illustrated Einstein's remarkable work in 1905 on Brownian motion, the photoelectric effect and special relativity. Thirteen school classes with 260 pupils, 30 teachers and 25 members…
Dutch museum marks Einstein anniversary
NASA Astrophysics Data System (ADS)
van Calmthout, Matijn
2016-01-01
A new painting of Albert Einstein's field equation from his 1915 general theory of relativity was unveiled in a ceremony in November 2015 by the Dutch physicist Robbert Dijkgraaf, who is director of the Princeton Institute for Advanced Study in the US.
Approaching Bose-Einstein Condensation
ERIC Educational Resources Information Center
Ferrari, Loris
2011-01-01
Bose-Einstein condensation (BEC) is discussed at the level of an advanced course of statistical thermodynamics, clarifying some formal and physical aspects that are usually not covered by the standard pedagogical literature. The non-conventional approach adopted starts by showing that the continuum limit, in certain cases, cancels out the crucial…
MONOPOLES AND DYONS IN THE PURE EINSTEIN YANG MILLS THEORY
HOSOTANI,Y.; BJORAKER,J.
1999-08-16
In the pure Einstein-Yang-Mills theory in four dimensions there exist monopole and dyon solutions. The spectrum of the solutions is discrete in asymptotically flat or de Sitter space, whereas it is continuous in asymptotically anti-de Sitter space. The solutions are regular everywhere and specified with their mass, and non-Abelian electric and magnetic charges. In asymptotically anti-de Sitter space a class of monopole solutions have no node in non-Abelian magnetic fields, and are stable against spherically symmetric perturbations.
Quantum Einstein Gravity and Asymptotic Safety
NASA Astrophysics Data System (ADS)
Forgács, Péter
2006-06-01
I review some of the salient points of the construction of a perturbative quantum theory of the dimensionally reduced pure Einstein gravity from 4 to 2 dimensions assuming that the 4 dimensional (4D) metrics admit two commuting Killing vectors. The dimensionally reduced theory corresponds to an O(1,2) symmetric σ-model coupled to two scalar fields in flat spacetime. It inherits the lack of standard perturbative renormalizability from 4D gravity, however, it turns out that strict cutoff independence can be achieved to all loop orders in a space of Lagrangians differing only by a field dependent conformal factor. The renormalization group flow possesses a unique non-Gaussian fixed point at which the trace anomaly vanishes. The existence of this non-Gaussian fixed point is compatible with Weinberg's "asymptotic safety" scenario.
Charged Particle Tunnels from the Einstein-Maxwell Black Hole
NASA Astrophysics Data System (ADS)
Chen, Deyou; Yang, Shuzheng
Considering the self-gravitation interaction and the unfixed background space-time, we study the Hawking radiation of the Einstein-Maxwell-Dilaton-Axion (EMDA) black hole by the radial geodesic method and the Hamilton-Jacobi method. Both sets of results agree with Parikh and Wilczek's and show that the actual radiation spectrum deviates from the purely thermal one and the tunneling probability is related to the change of Bekenstein-Hawking entropy, which satisfies an underlying unitary theory.
Einstein's equations and a cosmology with finite matter
NASA Astrophysics Data System (ADS)
Clavelli, L.; Goldstein, Gary R.
2015-04-01
We discuss various space-time metrics which are compatible with Einstein's equations and a previously suggested cosmology with a finite total mass.1 In this alternative cosmology, the matter density was postulated to be a spatial delta function at the time of the big bang thereafter diffusing outward with constant total mass. This proposal explores a departure from standard assumptions that the big bang occurred everywhere at once or was just one of an infinite number of previous and later transitions.
HST image of Gravitational Lens G2237 + 305 or 'Einstein Cross'
NASA Technical Reports Server (NTRS)
1990-01-01
European Space Agency (ESA) Faint Object Camera (FOC) science image was taken from the Hubble Space Telescope (HST) of Gravitational Lens G2237 + 305 or 'Einstein Cross'. The gravitational lens G2237 + 305 or 'Einstein Cross' shows four images of a very distant quasar which has been multiple-imaged by a relatively nearby galaxy acting as a gravitational lens. The angular separation between the upper and lower images is 1.6 arc seconds. Photo was released from Goddard Space Flight Center (GSFC) 09-12-90.
Parameterized Beyond-Einstein Growth
Linder, Eric; Linder, Eric V.; Cahn, Robert N.
2007-09-17
A single parameter, the gravitational growth index gamma, succeeds in characterizing the growth of density perturbations in the linear regime separately from the effects of the cosmic expansion. The parameter is restricted to a very narrow range for models of dark energy obeying the laws of general relativity but can take on distinctly different values in models of beyond-Einstein gravity. Motivated by the parameterized post-Newtonian (PPN) formalism for testing gravity, we analytically derive and extend the gravitational growth index, or Minimal Modified Gravity, approach to parameterizing beyond-Einstein cosmology. The analytic formalism demonstrates how to apply the growth index parameter to early dark energy, time-varying gravity, DGP braneworld gravity, and some scalar-tensor gravity.
Could we now convince Einstein?
NASA Astrophysics Data System (ADS)
Accardi, Luigi
2006-01-01
The present conference takes place in the same year that celebrates the centenary of Albert Einstein. Hence it is a good occasion to reflect on those problems which have been at the core of Einstein's intellectual activity. Undoubtedly the foundation of quantum mechanics (QM) is one of these problems. It is known that Einstein was never convinced by the interpretation of quantum mechanics accepted, in his times and still now, by the majority of physicists. The fact that he was sharing this skepticism with people like Schrödinger and, most of all, the fact that no convincing answer, to the doubts of these people, had emerged in a more than half a century old debate, helped in keeping alive the attention of a growing number of people on this problem. The crucial issue is that the standard interpretation of QM has some physical implications which are experimentally verifiable and which, for several years, have been thought to be incompatible with relativity theory (the so-called "quantum nonlocality"). On the other hand alternative, more intuitive, interpretations (such as the ensemble interpretation) seemed to be ruled out from very well confirmed experimental data. The way out from this impasse has required a deep analysis of the connections between mathematics and physics as well as the emergence of new ideas both in mathematics (non-Kolmogorovian probabilities) and in physics (the theory of adaptive systems). The Einstein centenary is a good occasion for a short survey of these developments with the goal of answering the intriguing question posed in the title of the present paper.
Analysis of regularizing properties of nonlinear electrodynamics in the Einstein-Born-Infeld theory
Denisov, V. I. Sokolov, V. A.
2011-12-15
New regularizing manifestations of the Einstein-Born-Infeld theory for a massive charged force center in the space-time are considered. The properties of isotropic geodesics in this space are analyzed. It is shown that the charge may exceed the maximum possible charge in the Reissner-Nordstroem solution; the possibility of eliminating one of the metric horizons is also noted.
Scientific productivity of Einstein, Freud and Landsteiner.
Kantha, S S
1996-05-01
The scientific productivity of Albert Einstein was compared to that of designated controls Karl Landsteiner (an experimental scientist) and Sigmund Freud (an eminent theorist). Three assumptions made for this comparison were (1) that Einstein and his designated controls had equal scientific stature; (2) that their publications were produced in a similar, if not identical, sociocultural milieu; and (3) the number of publications is directly proportional to scientific productivity. At the end of their illustrious careers, Einstein, Freud and Landsteiner accumulated 315, 320 and 345 scientific publications respectively. Einstein was the sole author in 88% of his publications, which validates the third assumption. Thus, one can conclude that quantitative comparison of Einstein's total scientific publications with that of appropriate controls such as Landsteiner and Freud shows that Einstein's chronic ill health did not influence his scientific productivity.
Einstein as a Missionary of Science
NASA Astrophysics Data System (ADS)
Renn, Jürgen
2013-10-01
The paper reviews Einstein's engagement as a mediator and popularizer of science. It discusses the formative role of popular scientific literature for the young Einstein, showing that not only his broad scientific outlook but also his internationalist political views were shaped by these readings. Then, on the basis of recent detailed studies, Einstein's travels and their impact on the dissemination of relativity theory are examined. These activities as well as Einstein's own popular writings are interpreted in the context of his understanding of science as part of human culture.
Polymer quantization of the Einstein-Rosen wormhole throat
Kunstatter, Gabor; Peltola, Ari; Louko, Jorma
2010-01-15
We present a polymer quantization of spherically symmetric Einstein gravity in which the polymerized variable is the area of the Einstein-Rosen wormhole throat. In the classical polymer theory, the singularity is replaced by a bounce at a radius that depends on the polymerization scale. In the polymer quantum theory, we show numerically that the area spectrum is evenly spaced and in agreement with a Bohr-Sommerfeld semiclassical estimate, and this spectrum is not qualitatively sensitive to issues of factor ordering or boundary conditions except in the lowest few eigenvalues. In the limit of small polymerization scale we recover, within the numerical accuracy, the area spectrum obtained from a Schroedinger quantization of the wormhole throat dynamics. The prospects of recovering from the polymer throat theory a full quantum-corrected spacetime are discussed.
Second post-Newtonian approximation of Einstein-aether theory
Xie Yi; Huang Tianyi
2008-06-15
In this paper, second post-Newtonian approximation of Einstein-aether theory is obtained by Chandrasekhar's approach. Five parametrized post-Newtonian parameters in first post-Newtonian approximation are presented after a time transformation and they are identical with previous works, in which {gamma}=1, {beta}=1, and two preferred-frame parameters remain. Meanwhile, in second post-Newtonian approximation, a parameter, which represents third order nonlinearity for gravity, is zero--the same as in general relativity. For an application for future deep space laser ranging missions, we reduce the metric coefficients for light propagation in a case of N point masses as a simplified model of the Solar System. The resulting light deflection angle in second post-Newtonian approximation poses another constraint on the Einstein-aether theory.
Interferometry with Bose-Einstein condensates in microgravity.
Müntinga, H; Ahlers, H; Krutzik, M; Wenzlawski, A; Arnold, S; Becker, D; Bongs, K; Dittus, H; Duncker, H; Gaaloul, N; Gherasim, C; Giese, E; Grzeschik, C; Hänsch, T W; Hellmig, O; Herr, W; Herrmann, S; Kajari, E; Kleinert, S; Lämmerzahl, C; Lewoczko-Adamczyk, W; Malcolm, J; Meyer, N; Nolte, R; Peters, A; Popp, M; Reichel, J; Roura, A; Rudolph, J; Schiemangk, M; Schneider, M; Seidel, S T; Sengstock, K; Tamma, V; Valenzuela, T; Vogel, A; Walser, R; Wendrich, T; Windpassinger, P; Zeller, W; van Zoest, T; Ertmer, W; Schleich, W P; Rasel, E M
2013-03-01
Atom interferometers covering macroscopic domains of space-time are a spectacular manifestation of the wave nature of matter. Because of their unique coherence properties, Bose-Einstein condensates are ideal sources for an atom interferometer in extended free fall. In this Letter we report on the realization of an asymmetric Mach-Zehnder interferometer operated with a Bose-Einstein condensate in microgravity. The resulting interference pattern is similar to the one in the far field of a double slit and shows a linear scaling with the time the wave packets expand. We employ delta-kick cooling in order to enhance the signal and extend our atom interferometer. Our experiments demonstrate the high potential of interferometers operated with quantum gases for probing the fundamental concepts of quantum mechanics and general relativity. PMID:23496709
Einstein as a Missionary of Science
ERIC Educational Resources Information Center
Renn, Jürgen
2013-01-01
The paper reviews Einstein's engagement as a mediator and popularizer of science. It discusses the formative role of popular scientific literature for the young Einstein, showing that not only his broad scientific outlook but also his internationalist political views were shaped by these readings. Then, on the basis of recent detailed…
What Einstein Can Teach Us about Education
ERIC Educational Resources Information Center
Hayes, Denis
2007-01-01
People are more likely to associate Einstein with complex scientific theories and mathematical calculations than with education theory. In fact, Einstein's own experiences of schooling and his reflections on the meaning of life and the significance of education are profound and oddly relevant to the situation that pertains in England today. It is…
Books on Einstein--Collectors' Delight
ERIC Educational Resources Information Center
Khoon, Koh Aik; Jalal, Azman; Abd-Shukor, R.; Yatim, Baharudin; Talib, Ibrahim Abu; Daud, Abdul Razak; Samat, Supian
2009-01-01
A survey of thirteen books on Einstein is presented. Its gives an idea on how much is written about the man and how frequent are the publications. The year 2005 saw the most publications. It is the centenary for the Miraculous Year. Interestingly some books can just sustain their readers' interest with just words. Einstein comes alive with the…
People Interview: Continuing Einstein's great work
NASA Astrophysics Data System (ADS)
2009-09-01
INTERVIEW Continuing Einstein's great work Dr Michio Kaku is a theoretical physicist, bestselling author and popularizer of science. He is the co-founder of string field theory (a branch of string theory) and continues Einstein's search to unite the four fundamental forces of nature into one unified theory. David Smith speaks to him about inspiration and education.
Albert Einstein's Magic Mountain: An Aarau Education*
NASA Astrophysics Data System (ADS)
Hunziker, Herbert
2015-03-01
For economic reasons, the electrotechnical factory J. Einstein & Cie. (co-owned by Albert Einstein's father Hermann) had to be closed in the summer of 1894. While Albert's parents emigrated to Italy to build a new existence, he remained in Munich to complete his studies at the Gymnasium. Left behind, however, he had a difficult time with what he considered the rigid educational practices at the Munich Luitpold-Gymnasium and quit without a diploma. The present article discusses Einstein's richly winding path to the Aargau Cantonal School (Switzerland), especially its history and educational philosophy during the time of his stay in Aarau. There, Einstein met some outstanding teachers, who could serve him as models of scholars and human beings. In spite of Einstein's distinct independence of mind, these personalities may well have had a significant influence on the alignment of his inner compass.
Astrophysical observations: lensing and eclipsing Einstein's theories.
Bennett, Charles L
2005-02-11
Albert Einstein postulated the equivalence of energy and mass, developed the theory of special relativity, explained the photoelectric effect, and described Brownian motion in five papers, all published in 1905, 100 years ago. With these papers, Einstein provided the framework for understanding modern astrophysical phenomena. Conversely, astrophysical observations provide one of the most effective means for testing Einstein's theories. Here, I review astrophysical advances precipitated by Einstein's insights, including gravitational redshifts, gravitational lensing, gravitational waves, the Lense-Thirring effect, and modern cosmology. A complete understanding of cosmology, from the earliest moments to the ultimate fate of the universe, will require developments in physics beyond Einstein, to a unified theory of gravity and quantum physics. PMID:15705841
Astrophysical Observations: Lensing and Eclipsing Einstein's Theories
NASA Astrophysics Data System (ADS)
Bennett, Charles L.
2005-02-01
Albert Einstein postulated the equivalence of energy and mass, developed the theory of special relativity, explained the photoelectric effect, and described Brownian motion in five papers, all published in 1905, 100 years ago. With these papers, Einstein provided the framework for understanding modern astrophysical phenomena. Conversely, astrophysical observations provide one of the most effective means for testing Einstein's theories. Here, I review astrophysical advances precipitated by Einstein's insights, including gravitational redshifts, gravitational lensing, gravitational waves, the Lense-Thirring effect, and modern cosmology. A complete understanding of cosmology, from the earliest moments to the ultimate fate of the universe, will require developments in physics beyond Einstein, to a unified theory of gravity and quantum physics.
Einstein Ring in Distant Universe
NASA Astrophysics Data System (ADS)
2005-06-01
Using ESO's Very Large Telescope, Rémi Cabanac and his European colleagues have discovered an amazing cosmic mirage, known to scientists as an Einstein Ring. This cosmic mirage, dubbed FOR J0332-3557, is seen towards the southern constellation Fornax (the Furnace), and is remarkable on at least two counts. First, it is a bright, almost complete Einstein ring. Second, it is the farthest ever found. ESO PR Photo 20a/05 ESO PR Photo 20a/05 Deep Image of a Region in Fornax (FORS/VLT) [Preview - JPEG: 400 x 434 pix - 60k] [Normal - JPEG: 800 x 867 pix - 276k] [Full Res - JPEG: 1859 x 2015 pix - 3.8M] ESO PR Photo 20b/05 ESO PR Photo 20b/05 Zoom-in on the Newly Found Einstein Ring (FORS/VLT) [Preview - JPEG: 400 x 575 pix - 168k] [Normal - JPEG: 630 x 906 pix - 880k] Caption: ESO PR Photo 20a/05 is a composite image taken in two bands (B and R) with VLT/FORS1 of a small portion of the sky (field-of-view 7x7' or 1/15th of the area of the full moon). The faintest object seen in the image has a magnitude 26, that is, it is 100 million times fainter than what can be observed with the unaided eye. The bright elliptical galaxy on the lower-left quadrant is a dwarf galaxy part of a large nearby cluster in the Fornax constellation. As for all deep images of the sky, this field shows a variety of objects, the brightest ponctual sources being stars from our Galaxy. By far the field is dominated by thousands of faint background galaxies the colours of which are related to the age of their dominant stellar population, their dust content and their distance. The newly found Einstein ring is visible in the top right part of the image. ESO PR Photo 20b/05 zooms-in on the position of the newly found cosmic mirage. ESO PR Photo 20c/05 ESO PR Photo 20c/05 Einstein Ring in Distant Universe (FORS/VLT) [Preview - JPEG: 400 x 584 pix - 104k] [Normal - JPEG: 800 x 1168 pix - 292k] [Full Res - JPEG: 1502 x 2192 pix - 684k] Caption of ESO PR Photo 20c/05: The left image is magnified and centred
The Media of Relativity: Einstein and Telecommunications Technologies.
Canales, Jimena
2015-07-01
How are fundamental constants, such as "c" for the speed of light, related to the technological environments that produce them? Relativistic cosmology, developed first by Albert Einstein, depended on military and commercial innovations in telecommunications. Prominent physicists (Hans Reichenbach, Max Born, Paul Langevin, Louis de Broglie, and Léon Brillouin, among others) worked in radio units during WWI and incorporated battlefield lessons into their research. Relativity physicists, working at the intersection of physics and optics by investigating light and electricity, responded to new challenges by developing a novel scientific framework. Ideas about lengths and solid bodies were overhauled because the old Newtonian mechanics assumed the possibility of "instantaneous signaling at a distance." Einstein's universe, where time and space dilated, where the shortest path between two points was often curved and non-Euclidean, followed the rules of electromagnetic "signal" transmission. For these scientists, light's constant speed in the absence of a gravitational field-a fundamental tenet of Einstein's theory-was a lesson derived from communication technologies.
The Media of Relativity: Einstein and Telecommunications Technologies.
Canales, Jimena
2015-07-01
How are fundamental constants, such as "c" for the speed of light, related to the technological environments that produce them? Relativistic cosmology, developed first by Albert Einstein, depended on military and commercial innovations in telecommunications. Prominent physicists (Hans Reichenbach, Max Born, Paul Langevin, Louis de Broglie, and Léon Brillouin, among others) worked in radio units during WWI and incorporated battlefield lessons into their research. Relativity physicists, working at the intersection of physics and optics by investigating light and electricity, responded to new challenges by developing a novel scientific framework. Ideas about lengths and solid bodies were overhauled because the old Newtonian mechanics assumed the possibility of "instantaneous signaling at a distance." Einstein's universe, where time and space dilated, where the shortest path between two points was often curved and non-Euclidean, followed the rules of electromagnetic "signal" transmission. For these scientists, light's constant speed in the absence of a gravitational field-a fundamental tenet of Einstein's theory-was a lesson derived from communication technologies. PMID:26387524
The Canarias Einstein ring: a newly discovered optical Einstein ring
NASA Astrophysics Data System (ADS)
Bettinelli, M.; Simioni, M.; Aparicio, A.; Hidalgo, S. L.; Cassisi, S.; Walker, A. R.; Piotto, G.; Valdes, F.
2016-09-01
We report the discovery of an optical Einstein ring in the Sculptor constellation, IAC J010127-334319, in the vicinity of the Sculptor dwarf spheroidal galaxy. It is an almost complete ring (˜300°) with a diameter of ˜4.5 arcsec. The discovery was made serendipitously from inspecting Dark Energy Camera (DECam) archive imaging data. Confirmation of the object nature has been obtained by deriving spectroscopic redshifts for both components, lens and source, from observations at the 10.4 m Gran Telescopio CANARIAS (GTC) with the spectrograph OSIRIS. The lens, a massive early-type galaxy, has a redshift of z = 0.581, while the source is a starburst galaxy with redshift of z = 1.165. The total enclosed mass that produces the lensing effect has been estimated to be Mtot = (1.86 ± 0.23) × 1012 M⊙.
Gravity Probe B: Testing Einstein with Gyroscopes
NASA Technical Reports Server (NTRS)
Geveden, Rex D.; May, Todd
2003-01-01
Some 40 years in the making, NASA' s historic Gravity Probe B (GP-B) mission is scheduled to launch aboard a Delta II in 2003. GP-B will test two extraordinary predictions from Einstein's General Relativity: geodetic precession and the Lense-Thirring effect (frame-dragging). Employing tiny, ultra-precise gyroscopes, GP-B features a measurement accuracy of 0.5 milli-arc-seconds per year. The extraordinary measurement precision is made possible by a host of breakthrough technologies, including electro-statically suspended, super-conducting quartz gyroscopes; virtual elimination of magnetic flux; a solid quartz star tracking telescope; helium microthrusters for drag-free control of the spacecraft; and a 2400 liter superfluid helium dewar. This paper will provide an overview of the science, key technologies, flight hardware, integration and test, and flight operations of the GP-B space vehicle. It will also examine some of the technical management challenges of a large-scale, technology-driven, Principal Investigator-led mission.
Gravity Probe B: Testing Einstein with Gyroscopes
NASA Technical Reports Server (NTRS)
Geveden, Rex D.; May, Todd
2003-01-01
Some 40 years in the making, NASA s historic Gravity Probe B (GP-B) mission is scheduled to launch aboard a Delta I1 in 2003. GP-B will test two extraordinary predictions from Einstein s General Relativity: geodetic precession and the Lense-Thirring effect (frame-dragging). Employing tiny, ultra-precise gyroscopes, GP-B features a measurement accuracy of 0.5 milli-arc-seconds per year. The extraordinary measurement precision is made possible by a host of breakthrough technologies, including electro-statically suspended, super-conducting quartz gyroscopes; virtual elimination of magnetic flux; a solid quartz star- tracking telescope; helium microthrusters for drag-free control of the spacecraft; and a 2400 liter superfluid helium dewar. This paper will provide an overview of the science, key technologies, flight hardware, integration and test, and flight operations of the GP-B space vehicle. It will also examine some of the technical management challenges of a large-scale, technology-driven, Principal Investigator-led mission.
BOOK REVIEW: Einstein's Jury: The Race to Test Relativity
NASA Astrophysics Data System (ADS)
Ehlers, Jürgen
2007-10-01
'I know very well that my theory rests on a shaky foundation. What attracts me to it is that it leads to consequences that seem to be accessible to experiment, and it provides a starting point for the theoretical understanding of gravitation', wrote Einstein in 1911. Einstein's Jury by Jeffrey Crelinsten—well documented, well written, and fascinating to read—describes how, from 1909 on, Einstein's two theories of relativity became known to astronomers, and how the predictions made between 1907 and 1915 were received as challenges to observers. The author gives a non-technical account of the efforts made until 1930 to test these predictions; he focuses on two of the three classical tests, namely gravitational redshift and bending of light; the 'jury' consists mainly of American observers—Adams, Campbell, Curtis, Hale, Perrin, St John, Trumpler and others—working with newly built large telescopes, and the Britons Eddington and Evershed. The major steps which, after a long struggle, convinced the majority of astronomers that Einstein was right, are narrated chronologically in rather great detail, especially the work at Lick Observatory, before and after the famous British observation of 1919, on solar eclipses, and the work at Mount Wilson and the Indian Kodaikanal Observatories to extract the gravitational redshift from the complicated spectrum of the sun. The account of the eclipse work which was carried out between 1918 and 1923 by Lick astronomers corrects the impression suggested by many historical accounts that the British expedition alone settled the light-bending question. Apart from these main topics, the anomalous perihelion advance of Mercury and the ether problem are covered. By concentrating on astronomy rather than on physics this book complements the rich but repetitive literature on Einstein and relativity which appeared in connection with the commemoration of Einstein's annus mirabilis, 2005. The well told stories include curiosities such as
From Newton's laws to Einstein's theory of relativity.
NASA Astrophysics Data System (ADS)
Fang, L.; Chu, Y.
Contents: 1. From Aristotle to Newton. 2. Space, time and motion. 3. From the classical composition of velocities to the constant speed of light. 4. From Galileo's principle of relativity to the special theory of relativity. 5. The relativity and absoluteness ofa rod and a clock. 6. Dynamic problems. 7. From the leaning tower of Pisa to the general theory of relativity. 8. From Newton to post-Newton. 9. From classical gravitational collapse to the black hole. 10. Theconfirmation of gravitational waves. 11. From Newton's universe to the expanding universe. 12. After Einstein.
Static solutions in D = 3 Einstein-Maxwell theory
NASA Technical Reports Server (NTRS)
Deser, S.; Mazur, P. O.
1985-01-01
The spacetime generated by a massive point charge in Einstein-Maxwell theory at three spacetime dimensions is obtained. Some of its properties include infinite total energy due to the slow fall off of the electric field, and necessary vanishing of the particle's charge if its mechanical mass is sufficient to close up space. Although g sub 00 vanishes on a coordinate circle, there is no event (but only a Killing) horizon and the curvature invariants are finite except at the source and at infinity. There are no static multi-charge solutions.
Composite nature of hadrons and Bose-Einstein correlations
NASA Astrophysics Data System (ADS)
Bialas, A.
2016-07-01
I am reporting results of two papers, written together with W.Florkowski and K.Zalewski [1, 2], discussing the consequences of the observation [3] that, due to their composite nature and thus finite size, hadrons observed in the HBT measurements must be correlated in space-time. Using the blast-wave model [4] adjusted [1] to ALICE data on the measured HBT radii in pp collisions at 7 TeV [5], the full Bose-Einstein correlation functions in three direction (out, side, long) are evaluated. The results are presented together with some additional comments.
The global Utiyama theorem in Einstein-Cartan theory
NASA Astrophysics Data System (ADS)
Bruzzo, Ugo
1987-09-01
A global formulation of Utiyama's theorem for Einstein-Cartan-type gravitational theories regarded as gauge theories of the group of space-time diffeomorphisms is given. The local conditions for the Lagrangian to be gauge invariant coincide with those found by other authors [A. Pérez-Rendón Collantes, ``Utiyama type theorems,'' in Poincaré Gauge Approach to Gravity. I, Proceedings Journées Relativistes 1984; A. Pérez-Rendón and J. J. Seisdedos, ``Utiyama type theorems in Poincaré gauge approach to gravity. II, '' Preprints de Mathematicas, Universidad de Salamanca, 1986] in Kibble's and Hehl's approaches.
Entanglement Equilibrium and the Einstein Equation.
Jacobson, Ted
2016-05-20
A link between the semiclassical Einstein equation and a maximal vacuum entanglement hypothesis is established. The hypothesis asserts that entanglement entropy in small geodesic balls is maximized at fixed volume in a locally maximally symmetric vacuum state of geometry and quantum fields. A qualitative argument suggests that the Einstein equation implies the validity of the hypothesis. A more precise argument shows that, for first-order variations of the local vacuum state of conformal quantum fields, the vacuum entanglement is stationary if and only if the Einstein equation holds. For nonconformal fields, the same conclusion follows modulo a conjecture about the variation of entanglement entropy.
Entanglement Equilibrium and the Einstein Equation
NASA Astrophysics Data System (ADS)
Jacobson, Ted
2016-05-01
A link between the semiclassical Einstein equation and a maximal vacuum entanglement hypothesis is established. The hypothesis asserts that entanglement entropy in small geodesic balls is maximized at fixed volume in a locally maximally symmetric vacuum state of geometry and quantum fields. A qualitative argument suggests that the Einstein equation implies the validity of the hypothesis. A more precise argument shows that, for first-order variations of the local vacuum state of conformal quantum fields, the vacuum entanglement is stationary if and only if the Einstein equation holds. For nonconformal fields, the same conclusion follows modulo a conjecture about the variation of entanglement entropy.
Oberheim, Eric
2016-06-01
Thomas Kuhn and Paul Feyerabend promote incommensurability as a central component of their conflicting accounts of the nature of science. This paper argues that in so doing, they both develop Albert Einstein's views, albeit in different directions. Einstein describes scientific revolutions as conceptual replacements, not mere revisions, endorsing 'Kant-on-wheels' metaphysics in light of 'world change'. Einstein emphasizes underdetermination of theory by evidence, rational disagreement in theory choice, and the non-neutrality of empirical evidence. Einstein even uses the term 'incommensurable' specifically to apply to challenges posed to comparatively evaluating scientific theories in 1949, more than a decade before Kuhn and Feyerabend. This analysis shows how Einstein anticipates substantial components of Kuhn and Feyerabend's views, and suggests that there are strong reasons to suspect that Kuhn and Feyerabend were directly inspired by Einstein's use of the term 'incommensurable', as well as his more general methodological and philosophical reflections.
Oberheim, Eric
2016-06-01
Thomas Kuhn and Paul Feyerabend promote incommensurability as a central component of their conflicting accounts of the nature of science. This paper argues that in so doing, they both develop Albert Einstein's views, albeit in different directions. Einstein describes scientific revolutions as conceptual replacements, not mere revisions, endorsing 'Kant-on-wheels' metaphysics in light of 'world change'. Einstein emphasizes underdetermination of theory by evidence, rational disagreement in theory choice, and the non-neutrality of empirical evidence. Einstein even uses the term 'incommensurable' specifically to apply to challenges posed to comparatively evaluating scientific theories in 1949, more than a decade before Kuhn and Feyerabend. This analysis shows how Einstein anticipates substantial components of Kuhn and Feyerabend's views, and suggests that there are strong reasons to suspect that Kuhn and Feyerabend were directly inspired by Einstein's use of the term 'incommensurable', as well as his more general methodological and philosophical reflections. PMID:27269260
Atom Interferometry on Sounding Rockets with Bose-Einstein Condensates
NASA Astrophysics Data System (ADS)
Seidel, Stephan T.; Becker, Dennis; Lachmann, Maike D.; Herr, Waldemar; Rasel, Ernst M.; Quantus Collaboration
2016-05-01
One of the fundamental postulates of our description of nature is the universality of free fall, stating that the force exerted upon an object due to gravity is independent of its constitution. A precise test of this assumption is the comparison of the free fall of two ultra-cold clouds of different atomic species via atom interferometry. Since the sensitivity of the measurement is proportional to the square of the propagation time in the interferometer, it can be increased by performing the experiments in microgravity. In order to fully utilize the potential of the experiments the usage of a Bose-Einstein-Condensate as the initial state is necessary, because it is characterized by a small initial size and a low expansion velocity. As a step towards the transfer of such a system into space three sounding rocket missions with atom interferometers are currently being prepared. The launch of the first mission, aimed at the first demonstration of a Bose-Einstein-Condensate in space and an atom interferometer based on it is planned for 2016 from ESRANGE, Sweden. It will be followed by two more missions that extend the scientific goals to the creation of degenerate mixtures and dual-species atom interferometry. This research is funded by the German Space Agency DLR under Grant Number DLR 50 1131-37.
Geometric properties of the magnetic Laplacian on the Euclidean 4-space
Kazmierowski, Dominique; Zinoun, Azzouz; Intissar, Ahmed
2010-12-15
When the four-dimensional Euclidean space is endowed with a covariant derivative that is either self-dual or antiself-dual and of constant curvature, the corresponding magnetic Laplacian is closely related to the sub-Laplacian of the quaternionic Heisenberg group. Some geometric properties of this operator are studied. In particular, it is proved that there exists a canonical orthogonal complex structure which provides a factorization in the sense of Schroedinger.
Stability of the Einstein static universe in Einstein-Cartan theory
Atazadeh, K.
2014-06-01
The existence and stability of the Einstein static solution have been built in the Einstein-Cartan gravity. We show that this solution in the presence of perfect fluid with spin density satisfying the Weyssenhoff restriction is cyclically stable around a center equilibrium point. Thus, study of this solution is interesting because it supports non-singular emergent cosmological models in which the early universe oscillates indeterminately about an initial Einstein static solution and is thus past eternal.
Observation of phase defects in quasi-two-dimensional Bose-Einstein condensates.
Stock, Sabine; Hadzibabic, Zoran; Battelier, Baptiste; Cheneau, Marc; Dalibard, Jean
2005-11-01
We have observed phase defects in quasi-2D Bose-Einstein condensates close to the condensation temperature. Either a single or several equally spaced condensates are produced by selectively evaporating the sites of a 1D optical lattice. When several clouds are released from the lattice and allowed to overlap, dislocation lines in the interference patterns reveal nontrivial phase defects.
The creativity of Einstein and astronomy
NASA Technical Reports Server (NTRS)
Zeldovich, Y. B.
1980-01-01
A discussion of Einstein's scientific achievements for the 100th anniversary of his birth is presented. His works dealing with thermodynamics are described, along with his quantum theory of radiation. Most of the article discusses his general theory of relativity.
Covariant Conformal Decomposition of Einstein Equations
NASA Astrophysics Data System (ADS)
Gourgoulhon, E.; Novak, J.
It has been shown1,2 that the usual 3+1 form of Einstein's equations may be ill-posed. This result has been previously observed in numerical simulations3,4. We present a 3+1 type formalism inspired by these works to decompose Einstein's equations. This decomposition is motivated by the aim of stable numerical implementation and resolution of the equations. We introduce the conformal 3-``metric'' (scaled by the determinant of the usual 3-metric) which is a tensor density of weight -2/3. The Einstein equations are then derived in terms of this ``metric'', of the conformal extrinsic curvature and in terms of the associated derivative. We also introduce a flat 3-metric (the asymptotic metric for isolated systems) and the associated derivative. Finally, the generalized Dirac gauge (introduced by Smarr and York5) is used in this formalism and some examples of formulation of Einstein's equations are shown.
Recent developments in Bose-Einstein condensation
Kalman, G.
1997-09-22
This paper contains viewgraphs on developments on Bose-Einstein condensation. Some topics covered are: strongly coupled coulomb systems; standard response functions of the first and second kind; dynamical mean field theory; quasi localized charge approximation; and the main equations.
How History Helped Einstein in Special Relativity
NASA Astrophysics Data System (ADS)
Martinez, Alberto
2013-04-01
I will discuss how the German intellectual movement known as ``critical history'' motivated several physicists in the late 1900s to radically analyze the fundamental principles of mechanics, leading eventually to Einstein's special theory of relativity. Eugen Karl Dühring, Johann Bernhard Stallo, Ludwig Lange, and Ernst Mach wrote critical histories of mechanics, some of which emphasized notions of relativity and observation, in opposition to old metaphysical concepts that seemed to infect the foundations of physics. This strand of critical history included the ``genetic method'' of analyzing how concepts develop over time, in our minds, by way of ordinary experiences, which by 1904 was young Albert Einstein's favorite approach for examining fundamental notions. Thus I will discuss how history contributed in Einstein's path to relativity, as well as comment more generally on Einstein's views on history.
Einstein/Roosevelt Letters: A Unit.
ERIC Educational Resources Information Center
Bodle, Walter S.
1985-01-01
The letters in this unit of study intended for secondary students are facsimile reproductions of the correspondence between Albert Einstein and President Roosevelt on the possibility of constructing an atomic bomb. Classroom activities are also suggested. (RM)
General Motors sued for 'denigrating' Einstein's image
NASA Astrophysics Data System (ADS)
Gwynne, Peter
2010-07-01
The US car giant General Motors (GM) has played down the consequences of a lawsuit against it for using the likeness of Albert Einstein in an advertisement for its Terrain sports utility vehicle (SUV).
The happiest thought of Einstein's life.
NASA Astrophysics Data System (ADS)
Heller, M.
It is a commonly told story that Einstein formulated his famous principle of equivalence when thinking about what happens in a freely falling elevator, and that it was an original idea of his genius distinguished by the rare capability to see deep problems in the most ordinary things. In the reading of Einstein's and Ernst Mach's works the author has discovered that it was not a physicist in an elevator which led to the principle of equivalence but rather somebody falling from a roof; moreover, the idea behind the principle was not invented by Einstein himself but rather read by him from the book by Mach entitled The Science of Mechanics. The influence this book had on young Einstein is very well known.
Einstein and General Relativity: Historical Perspectives.
ERIC Educational Resources Information Center
Chandrasekhar, S.
1979-01-01
This paper presented in the 1978 Oppenheimer Memorial Lecture at Los Alamos Scientific Laboratories on August 17, 1978, discusses Einstein's contributions to physics, in particular, his discovery of the general theory of relativity. (HM)
NASA Astrophysics Data System (ADS)
Herrmann, Dieter B.
After Einstein came to Berlin, he gave his first popular lecture in the Archenhold Observatory, in 1915, on the special and the general theories of relativity. From then on, friendly relations grew between Archenhold and Einstein, which led to a permanent connection between the Observatory and Einstein's achievement. This contribution presents the background of the connection between Archenhold and Einstein, and the later activities in popularizing Einstein's work up to the year 2005.
Einstein-First: Changing the Paradigm of School Physics Education
NASA Astrophysics Data System (ADS)
Kaur, Tejinder
2015-08-01
The early years of high school physics are focused on Newtonian physics with little mention of the fundamental conceptual breakthroughs made by Einstein and others in the 20th century that underlie our current description of reality, collectively referred to here as Einsteinian Physics.Students’ conception of the Universe is still defined by Newton’s laws of motion and gravitation based on Euclidian-space. When Einsteinian Physics is eventually encountered, i.e. in university physics, astronomy and astrophysics classrooms, the contradictory concepts are difficult to understand intuitively.The Einstein-First project is investigating methods and strategies for incorporating Einsteinian Physics into the curriculum at a stage where it would comprise students’ first exposure to physics. Concepts fundamental to the modern paradigm such as curved space, warped time, photons and the uncertainty principle are introduced as the primary conceptualization of reality. From these foundations students can make the transition to the Euclidean-Newtonian model, which remains useful for many practical applications.Course programs consist of conceptual content and simple analogy-based activities, which have been developed to bring the relevant topics to life. The course also utilizes astrophysical observations to provide concrete examples of Einsteinian Physics in the Universe. Our telescope facilitates first-hand observations of these phenomenaThe efficacy of these programs has been investigated in multiple pilot studies by administering carefully designed tests, both before the program and after, to students of various levels of ability. Early results have been encouraging.This talk will present an overview of the Einstein-First program, including videos and demonstrations of course content and activities, as well as pilot study results, which suggest it is possible to present this material in a way that students, irrespective of ability and background, are appropriately
Why does a ball fall?: A new visualization for Einstein's model of gravity
NASA Astrophysics Data System (ADS)
Gould, Roy R.
2016-05-01
Many physics teachers seek a simple illustration of Einstein's model of gravity, suitable for the introductory physics classroom. In this article, we show that an ordinary wall map of the world can be used to contrast Newton's and Einstein's explanations for why a ball falls when released. Trajectories on the map are analogous to the trajectories of the ball through spacetime, because the geometry of the map is remarkably similar to the geometry of spacetime near Earth's surface. To aid in the pedagogy, we focus on the concept of scale rather than curvature. We show that, contrary to popular visualizations of Einstein's model, it is primarily the warping of time, not space, that causes a ball to fall, and we address the question of why we do not see the distortion of spacetime around us. Finally, we recover Newton's results for the falling ball from our geometrical treatment.
Noether charges and black hole mechanics in Einstein-aether theory
Foster, Brendan Z.
2006-01-15
The Noether charge method for defining the Hamiltonian of a diffeomorphism-invariant field theory is applied to 'Einstein-aether' theory, in which gravity couples to a dynamical, timelike, unit-norm vector field. Using the method, expressions are obtained for the total energy, momentum, and angular momentum of an Einstein-aether space-time. The method is also used to discuss the mechanics of Einstein-aether black holes. The derivation of Wald, and Iyer and Wald, of the first law of black hole thermodynamics fails for this theory because the unit-vector is necessarily singular at the bifurcation surface of the Killing horizon. A general identity relating variations of energy and angular momentum to a surface integral at the horizon is obtained, but a thermodynamic interpretation, including a definitive expression for the black hole entropy, is not found.
Noether charges and black hole mechanics in Einstein-aether theory
NASA Astrophysics Data System (ADS)
Foster, Brendan Z.
2006-01-01
The Noether charge method for defining the Hamiltonian of a diffeomorphism-invariant field theory is applied to “Einstein-aether” theory, in which gravity couples to a dynamical, timelike, unit-norm vector field. Using the method, expressions are obtained for the total energy, momentum, and angular momentum of an Einstein-aether space-time. The method is also used to discuss the mechanics of Einstein-aether black holes. The derivation of Wald, and Iyer and Wald, of the first law of black hole thermodynamics fails for this theory because the unit-vector is necessarily singular at the bifurcation surface of the Killing horizon. A general identity relating variations of energy and angular momentum to a surface integral at the horizon is obtained, but a thermodynamic interpretation, including a definitive expression for the black hole entropy, is not found.
Thermalization and Bose-Einstein condensation of quantum light in bulk nonlinear media
NASA Astrophysics Data System (ADS)
Chiocchetta, A.; Larré, P.-É.; Carusotto, I.
2016-07-01
We study the thermalization and the Bose-Einstein condensation of a paraxial, spectrally narrow beam of quantum light propagating in a lossless bulk Kerr medium. The spatiotemporal evolution of the quantum optical field is ruled by a Heisenberg equation analogous to the quantum nonlinear Schrödinger equation of dilute atomic Bose gases. Correspondingly, in the weak-nonlinearity regime, the phase-space density evolves according to the Boltzmann equation. Expressions for the thermalization time and for the temperature and the chemical potential of the eventual Bose-Einstein distribution are found. After discussing experimental issues, we introduce an optical setup allowing the evaporative cooling of a guided beam of light towards Bose-Einstein condensation. This might serve as a novel source of coherent light.
Relationship between the Einstein-Laub electromagnetic force and the Lorentz force on free charge
NASA Astrophysics Data System (ADS)
Webb, Kevin J.
2016-08-01
An electromagnetic force density expression that is consistent with a development attributed to Einstein and Laub appears to be able to describe optical force experiments done to date with homogenized media. However, a major question that has persisted for about one century relates to the apparent discrepancy with the usual interpretation of the force description due to Lorentz in magnetized media. Specifically, it had appeared that the Einstein and Laub force density incorporated only the free-space permeability in relation to the force on the electric current density. It is shown here that the Einstein and Laub force density is consistent with the Lorentz picture in the static limit. This resolves a key impediment in establishing a unified force density description for electromagnetic waves interacting with matter.
Classical and quantum dynamics of a model for atomic-molecular Bose-Einstein condensates
Santos, G.; Tonel, A.; Foerster, A.; Links, J.
2006-02-15
We study a model for a two-mode atomic-molecular Bose-Einstein condensate. Starting with a classical analysis we determine the phase space fixed points of the system. It is found that bifurcations of the fixed points naturally separate the coupling parameter space into four regions. The different regions give rise to qualitatively different dynamics. We then show that this classification holds true for the quantum dynamics.
Einstein@Home Finds an Elusive Pulsar
NASA Astrophysics Data System (ADS)
Kohler, Susanna
2015-08-01
Since the release of the second Fermi-LAT catalog in 2012, astronomers have been hunting for 3FGL J1906.6+0720, a gamma-ray source whose association couldn't be identified. Now, personal-computer time volunteered through the Einstein@Home project has resulted in the discovery of a pulsar that has been hiding from observers for years. A Blind Search: Identifying sources detected by Fermi-LAT can be tricky: the instrument's sky resolution is limited, so the position of the source can be hard to pinpoint. The gamma-ray source 3FGL J1906.6+0720 appeared in both the second and third Fermi-LAT source catalogs, but even after years of searching, no associated radio or X-ray source had been found. A team of researchers, led by Colin Clark of the Max Planck Institute for Gravitational Physics, suspected that the source might be a gamma-ray pulsar. To confirm this, however, they needed to detect pulsed emission — something inherently difficult given the low photon count and the uncertain position of the source. The team conducted a blind search for pulsations coming from the general direction of the gamma-ray source. Two things were needed for this search: clever data analysis and a lot of computing power. The data analysis algorithm was designed to be adaptive: it searched a 4-dimensional parameter space that included a safety margin, allowing the algorithm to wander if the source was at the edge of the parameter space. The computing power was contributed by tens of thousands of personal computers volunteered by participants in the Einstein@Home project, making much shorter work out of a search that would have required dozens of years on a single laptop. The sky region around the newly discovered pulsar. The dotted ellipse shows the 3FGL catalog 95% confidence region for the source. The data analysis algorithm was designed to search an area 50% larger (given by the dashed ellipse), but it was allowed to “walk away” within the gray shaded region if the source seemed to
Einstein's Revolutionary Light-Quantum Hypothesis
NASA Astrophysics Data System (ADS)
Stuewer, Roger H.
2005-05-01
The paper in which Albert Einstein proposed his light-quantum hypothesis was the only one of his great papers of 1905 that he himself termed ``revolutionary.'' Contrary to widespread belief, Einstein did not propose his light-quantum hypothesis ``to explain the photoelectric effect.'' Instead, he based his argument for light quanta on the statistical interpretation of the second law of thermodynamics, with the photoelectric effect being only one of three phenomena that he offered as possible experimental support for it. I will discuss Einstein's light-quantum hypothesis of 1905 and his introduction of the wave-particle duality in 1909 and then turn to the reception of his work on light quanta by his contemporaries. We will examine the reasons that prominent physicists advanced to reject Einstein's light-quantum hypothesis in succeeding years. Those physicists included Robert A. Millikan, even though he provided convincing experimental proof of the validity of Einstein's equation of the photoelectric effect in 1915. The turning point came after Arthur Holly Compton discovered the Compton effect in late 1922, but even then Compton's discovery was contested both on experimental and on theoretical grounds. Niels Bohr, in particular, had never accepted the reality of light quanta and now, in 1924, proposed a theory, the Bohr-Kramers-Slater theory, which assumed that energy and momentum were conserved only statistically in microscopic interactions. Only after that theory was disproved experimentally in 1925 was Einstein's revolutionary light-quantum hypothesis generally accepted by physicists---a full two decades after Einstein had proposed it.
Numerical stability for finite difference approximations of Einstein's equations
Calabrese, G. . E-mail: G.Calabrese@soton.ac.uk; Hinder, I.; Husa, S.
2006-11-01
We extend the notion of numerical stability of finite difference approximations to include hyperbolic systems that are first order in time and second order in space, such as those that appear in numerical relativity and, more generally, in Hamiltonian formulations of field theories. By analyzing the symbol of the second order system, we obtain necessary and sufficient conditions for stability in a discrete norm containing one-sided difference operators. We prove stability for certain toy models and the linearized Nagy-Ortiz-Reula formulation of Einstein's equations. We also find that, unlike in the fully first order case, standard discretizations of some well-posed problems lead to unstable schemes and that the Courant limits are not always simply related to the characteristic speeds of the continuum problem. Finally, we propose methods for testing stability for second order in space hyperbolic systems.
Coherence, Abstraction, and Personal Involvement: Albert Einstein, Physicist and Humanist.
ERIC Educational Resources Information Center
Ne'eman, Yuval
1979-01-01
Reviews Einstein's main contributions to physics, and analyzes the importance of a coherent body of theory. Einstein's involvement in nonscientific issues such as nuclear disarmament is also included. (HM)
Albert Einstein - And the Frontiers of Physics
NASA Astrophysics Data System (ADS)
Bernstein, Jeremy
1997-11-01
Albert Einstein did not impress his first teachers. They found him a dreamy child without an especially promising future. But some time in his early years he developed what he called "wonder" about the world. Later in life, he remembered two instances from his childhood--his fascination at age five with a compass and his introduction to the lucidity and certainty of geometry--that may have been the first signs of what was to come. From these ordinary beginnings, Einstein became one of the greatest scientific thinkers of all time. This illuminating biography describes in understandable language the experiments and revolutionary theories that flowed from Einstein's imagination and intellect--from his theory of relativity, which changed our conception of the universe and our place in it, to his search for a unified field theory that would explain all of the forces in the universe.
Einstein, Ethics and the Atomic Bomb
NASA Astrophysics Data System (ADS)
Rife, Patricia
2005-03-01
Einstein voiced his ethical views against war as well as fascism via venues and alliances with a variety of organizations still debated today. In 1939, he signed a letter to President Roosevelt (drafted by younger colleagues Szilard, Wigner and others) warning the U.S.government about the danger of Nazi Germany gaining control of uranium in the Belgian-controlled Congo in order to develop atomic weapons, based on the discovery of fission by Otto Hahn and Lise Meitner. In 1945, he became a member of the Princeton-based ``Emergency Committee for Atomic Scientists'' organized by Bethe, Condon, Bacher, Urey, Szilard and Weisskopf. Rare Einstein slides will illustrate Dr.Rife's presentation on Albert Einstein's philosophic and ethical convictions about peace, and public stance against war (1914-1950).
Classes of exact Einstein Maxwell solutions
NASA Astrophysics Data System (ADS)
Komathiraj, K.; Maharaj, S. D.
2007-12-01
We find new classes of exact solutions to the Einstein Maxwell system of equations for a charged sphere with a particular choice of the electric field intensity and one of the gravitational potentials. The condition of pressure isotropy is reduced to a linear, second order differential equation which can be solved in general. Consequently we can find exact solutions to the Einstein Maxwell field equations corresponding to a static spherically symmetric gravitational potential in terms of hypergeometric functions. It is possible to find exact solutions which can be written explicitly in terms of elementary functions, namely polynomials and product of polynomials and algebraic functions. Uncharged solutions are regainable with our choice of electric field intensity; in particular we generate the Einstein universe for particular parameter values.
Human dynamics: Darwin and Einstein correspondence patterns.
Oliveira, João Gama; Barabási, Albert-László
2005-10-27
In an era when letters were the main means of exchanging scientific ideas and results, Charles Darwin (1809-82) and Albert Einstein (1879-1955) were notably prolific correspondents. But did their patterns of communication differ from those associated with the instant-access e-mail of modern times? Here we show that, although the means have changed, the communication dynamics have not: Darwin's and Einstein's patterns of correspondence and today's electronic exchanges follow the same scaling laws. However, the response times of their surface-mail communication is described by a different scaling exponent from e-mail communication, providing evidence for a new class of phenomena in human dynamics.
Using worksheets to solve the Einstein equation
NASA Astrophysics Data System (ADS)
Moore, Thomas A.
2016-05-01
This article describes how one can use worksheets to guide undergraduate students through the process of finding solutions to specific cases of the Einstein equation of general relativity. The worksheets provide expressions for a metric's Christoffel symbols and Ricci tensor components for fairly general metrics. Students can use a worksheet to adapt these expressions to specific cases where symmetry or other considerations constrain the metric components' dependencies, and then use the worksheet's results to reduce the Einstein equation to a set of simpler differential equations that they can solve. This article illustrates the process for both a diagonal metric and a metric with one off-diagonal element.
Secrets of the Old One: Einstein, 1905
NASA Astrophysics Data System (ADS)
Bernstein, Jeremy
Beginning on the 18th of March, 1905,at approximately eight week intervals, the noted German physics journal Annalen der Physik received three hand-written manuscripts from a relatively unknown patent examiner in Bern. The patent examiner was the twenty-six year old Albert Einstein and the three papers would set the agenda for twentieth century physics. A fourth short paper was received by the journal on the 27th of September. It contained Einstein's derivation of the formula E=mc2. These papers with their many technological ramifications changed our lives in the twentieth century and beyond.
Bose-Einstein condensation of erbium.
Aikawa, K; Frisch, A; Mark, M; Baier, S; Rietzler, A; Grimm, R; Ferlaino, F
2012-05-25
We report on the achievement of Bose-Einstein condensation of erbium atoms and on the observation of magnetic Feshbach resonances at low magnetic fields. By means of evaporative cooling in an optical dipole trap, we produce pure condensates of 168Er, containing up to 7×10(4) atoms. Feshbach spectroscopy reveals an extraordinary rich loss spectrum with six loss resonances already in a narrow magnetic-field range up to 3 G. Finally, we demonstrate the application of a low-field Feshbach resonance to produce a tunable dipolar Bose-Einstein condensate and we observe its characteristic d-wave collapse. PMID:23003221
Beyond Einstein: Exploring the Extreme Universe
NASA Technical Reports Server (NTRS)
Barbier, Louis M.
2005-01-01
This paper will give an overview of the NASA Universe Division Beyond Einstein program. The Beyond Einstein program consists of a series of exploratory missions to investigate some of the most important and pressing problems in modern-day astrophysics - including searches for Dark Energy and studies of the earliest times in the universe, during the inflationary period after the Big Bang. A variety of new technologies are being developed both in the science instrumentation these missions will carry and in the spacecraft that will carry those instruments.
C. N. Yang on Einstein and Newton
NASA Astrophysics Data System (ADS)
2015-11-01
In Professor C. N. Yang’s view, Einstein’s strength was in his ability to distinguish what was truly important and to investigate it. Also, Einstein was unique in that he was able to zoom in as well as zoom out, just like a film which has both close-up and long shots. Many people are only able to have one view, either close-up or from afar, and cannot switch between the two. Professor C. N. Yang feels that, in the history of physics, only Newton can be compared with Einstein. Although Maxwell and Boltzmann were prominent physicists, their influence was not as great as Einstein’s.
Human dynamics: Darwin and Einstein correspondence patterns
NASA Astrophysics Data System (ADS)
Oliveira, João Gama; Barabási, Albert-László
2005-10-01
In an era when letters were the main means of exchanging scientific ideas and results, Charles Darwin (1809-82) and Albert Einstein (1879-1955) were notably prolific correspondents. But did their patterns of communication differ from those associated with the instant-access e-mail of modern times? Here we show that, although the means have changed, the communication dynamics have not: Darwin's and Einstein's patterns of correspondence and today's electronic exchanges follow the same scaling laws. However, the response times of their surface-mail communication is described by a different scaling exponent from e-mail communication, providing evidence for a new class of phenomena in human dynamics.
Bose-Einstein condensation. Twenty years after
Bagnato, V. S.; Frantzeskakis, D. J.; Kevrekidis, P. G.; Malomed, B. A.; Mihalache, D.
2015-02-23
The aim of this introductory article is two-fold. First, we aim to offer a general introduction to the theme of Bose-Einstein condensates, and briefly discuss the evolution of a number of relevant research directions during the last two decades. Second, we introduce and present the articles that appear in this Special Volume of Romanian Reports in Physics celebrating the conclusion of the second decade since the experimental creation of Bose-Einstein condensation in ultracold gases of alkali-metal atoms.
Einstein - Peace Now!: Visions and Ideas
NASA Astrophysics Data System (ADS)
Braun, Reiner; Krieger, David
2005-09-01
Einstein was not only an extraordinary scientist, but also a person who faced his social responsibilities determinedly. The main focus of this book is put on topical articles by Scientific and Peace Nobel Prize laureates, prominent scientists and those committed to peace issues and justice, as well as citizens engagement for peace. Among the contributors are more than 10 Nobel Prize laureates, such as Mikhail Gorbachev, Walter Kohn, Joseph Rotblat, Alexander Ginzburg or Hans Bethe. This unique collection of intellectual thoughts on Einstein's vision of peace addresses a thoughtful, concerned and courageous audience, and was compiled to encourage and envision ways towards a more peaceful society.
Propagating torsion in the Einstein frame
Poplawski, Nikodem J.
2006-11-15
The Einstein-Cartan-Saa theory of torsion modifies the spacetime volume element so that it is compatible with the connection. The condition of connection compatibility gives constraints on torsion, which are also necessary for the consistence of torsion, minimal coupling, and electromagnetic gauge invariance. To solve the problem of positivity of energy associated with the torsionic scalar, we reformulate this theory in the Einstein conformal frame. In the presence of the electromagnetic field, we obtain the Hojman-Rosenbaum-Ryan-Shepley theory of propagating torsion with a different factor in the torsionic kinetic term.
Conceptual Development of Einstein's Mass-Energy Relationship
ERIC Educational Resources Information Center
Wong, Chee Leong; Yap, Kueh Chin
2005-01-01
Einstein's special theory of relativity was published in 1905. It stands as one of the greatest intellectual achievements in the history of human thought. Einstein described the equivalence of mass and energy as "the most important upshot of the special theory of relativity" (Einstein, 1919). In this paper, we will discuss the evolution of the…
Geometric properties of static Einstein-Maxwell dilaton horizons with a Liouville potential
Abdolrahimi, Shohreh; Shoom, Andrey A.
2011-05-15
We study nondegenerate and degenerate (extremal) Killing horizons of arbitrary geometry and topology within the Einstein-Maxwell-dilaton model with a Liouville potential (the EMdL model) in d-dimensional (d{>=}4) static space-times. Using Israel's description of a static space-time, we construct the EMdL equations and the space-time curvature invariants: the Ricci scalar, the square of the Ricci tensor, and the Kretschmann scalar. Assuming that space-time metric functions and the model fields are real analytic functions in the vicinity of a space-time horizon, we study the behavior of the space-time metric and the fields near the horizon and derive relations between the space-time curvature invariants calculated on the horizon and geometric invariants of the horizon surface. The derived relations generalize similar relations known for horizons of static four- and five-dimensional vacuum and four-dimensional electrovacuum space-times. Our analysis shows that all the extremal horizon surfaces are Einstein spaces. We present the necessary conditions for the existence of static extremal horizons within the EMdL model.
BOOK REVIEW: Einstein's Jury: The Race to Test Relativity
NASA Astrophysics Data System (ADS)
Ehlers, Jürgen
2007-10-01
'I know very well that my theory rests on a shaky foundation. What attracts me to it is that it leads to consequences that seem to be accessible to experiment, and it provides a starting point for the theoretical understanding of gravitation', wrote Einstein in 1911. Einstein's Jury by Jeffrey Crelinsten—well documented, well written, and fascinating to read—describes how, from 1909 on, Einstein's two theories of relativity became known to astronomers, and how the predictions made between 1907 and 1915 were received as challenges to observers. The author gives a non-technical account of the efforts made until 1930 to test these predictions; he focuses on two of the three classical tests, namely gravitational redshift and bending of light; the 'jury' consists mainly of American observers—Adams, Campbell, Curtis, Hale, Perrin, St John, Trumpler and others—working with newly built large telescopes, and the Britons Eddington and Evershed. The major steps which, after a long struggle, convinced the majority of astronomers that Einstein was right, are narrated chronologically in rather great detail, especially the work at Lick Observatory, before and after the famous British observation of 1919, on solar eclipses, and the work at Mount Wilson and the Indian Kodaikanal Observatories to extract the gravitational redshift from the complicated spectrum of the sun. The account of the eclipse work which was carried out between 1918 and 1923 by Lick astronomers corrects the impression suggested by many historical accounts that the British expedition alone settled the light-bending question. Apart from these main topics, the anomalous perihelion advance of Mercury and the ether problem are covered. By concentrating on astronomy rather than on physics this book complements the rich but repetitive literature on Einstein and relativity which appeared in connection with the commemoration of Einstein's annus mirabilis, 2005. The well told stories include curiosities such as
[Albert Einstein and his abdominal aortic aneurysm].
Cervantes Castro, Jorge
2011-01-01
The interesting case of Albert Einstein's abdominal aortic aneurysm is presented. He was operated on at age 69 and, finding that the large aneurysm could not be removed, the surgeon elected to wrap it with cellophane to prevent its growth. However, seven years later the aneurysm ruptured and caused the death of the famous scientist.
New Information about Albert Einstein's Brain.
Falk, Dean
2009-01-01
In order to glean information about hominin (or other) brains that no longer exist, details of external neuroanatomy that are reproduced on endocranial casts (endocasts) from fossilized braincases may be described and interpreted. Despite being, of necessity, speculative, such studies can be very informative when conducted in light of the literature on comparative neuroanatomy, paleontology, and functional imaging studies. Albert Einstein's brain no longer exists in an intact state, but there are photographs of it in various views. Applying techniques developed from paleoanthropology, previously unrecognized details of external neuroanatomy are identified on these photographs. This information should be of interest to paleoneurologists, comparative neuroanatomists, historians of science, and cognitive neuroscientists. The new identifications of cortical features should also be archived for future scholars who will have access to additional information from improved functional imaging technology. Meanwhile, to the extent possible, Einstein's cerebral cortex is investigated in light of available data about variation in human sulcal patterns. Although much of his cortical surface was unremarkable, regions in and near Einstein's primary somatosensory and motor cortices were unusual. It is possible that these atypical aspects of Einstein's cerebral cortex were related to the difficulty with which he acquired language, his preference for thinking in sensory impressions including visual images rather than words, and his early training on the violin.
Albert Einstein and the Quantum Riddle
ERIC Educational Resources Information Center
Lande, Alfred
1974-01-01
Derives a systematic structure contributing to the solution of the quantum riddle in Einstein's sense by deducing quantum mechanics from the postulates of symmetry, correspondence, and covariance. Indicates that the systematic presentation is in agreement with quantum mechanics established by Schroedinger, Born, and Heisenberg. (CC)
Chromohydrodynamics in Einstein-Cartan theory
Amorim, R.
1986-05-15
The complete dynamical system for a classical fluid endowed with non-Abelian charge density is obtained by using variational techniques. Spin density appears in a natural way, as a consequence of a usual gauge construction. Einstein-Cartan, Yang-Mills, and generalized Wong equations are explicitly shown.
The Einstein All-Sky Slew Survey
NASA Technical Reports Server (NTRS)
Elvis, Martin S.
1992-01-01
The First Einstein IPC Slew Survey produced a list of 819 x-ray sources, with f(sub x) approximately 10(exp -12) - 10(exp -10) erg/sq cm s and positional accuracy of approximately 1.2 feet (90 percent radius). The aim of this program was to identify these x-ray sources.
Soliton resonance in bose-einstein condensate
NASA Technical Reports Server (NTRS)
Zak, Michail; Kulikov, I.
2002-01-01
A new phenomenon in nonlinear dispersive systems, including a Bose-Einstein Condensate (BEC), has been described. It is based upon a resonance between an externally induced soliton and 'eigen-solitons' of the homogeneous cubic Schrodinger equation. There have been shown that a moving source of positive /negative potential induces bright /dark solitons in an attractive / repulsive Bose condensate.
Einstein Slew Survey: Data analysis innovations
NASA Technical Reports Server (NTRS)
Elvis, Martin S.; Plummer, David; Schachter, Jonathan F.; Fabbiano, G.
1992-01-01
Several new methods were needed in order to make the Einstein Slew X-ray Sky Survey. The innovations which enabled the Slew Survey to be done are summarized. These methods included experimental approach to large projects, parallel processing on a LAN, percolation source detection, minimum action identifications, and rapid dissemination of the whole data base.
Einstein Observations of Galactic supernova remnants
NASA Technical Reports Server (NTRS)
Seward, Frederick D.
1990-01-01
This paper summarizes the observations of Galactic supernova remnants with the imaging detectors of the Einstein Observatory. X-ray surface brightness contours of 47 remnants are shown together with gray-scale pictures. Count rates for these remnants have been derived and are listed for the HRI, IPC, and MPC detectors.
Einstein's Jury -The Race to Test Relativity
NASA Astrophysics Data System (ADS)
Crelinsten, Jeffrey
2006-12-01
It is common belief that Einstein’s general theory of relativity won worldwide acceptance after British astronomers announced in November 1919 that the sun’s gravitational field bends starlight by an amount predicted by Einstein. This paper demonstrates that the case for Einstein was not settled until much later and that there was considerable confusion and debate about relativity during this period. Most astronomers considered Einstein’s general theory too metaphysical and abstruse, and many tried to find more conventional explanations of the astronomical observations. Two American announcements before the British results appeared had been contrary to Einstein’s prediction. They came from Lick and Mt. Wilson observatories, which enjoyed international reputations as two of the most advanced astrophysical research establishments in the world. Astronomers at these renowned institutions were instrumental in swaying the court of scientific opinion during the decade of the 1920s, which saw numerous attempts to measure light-bending, as well as solar line displacements and even ether-drift. How astronomers approached the “Einstein problem” in these early years before and after the First World War, and how the public reacted to what they reported, helped to shape attitudes we hold today about Einstein and his ideas.
The Foundations of Einstein's Theory of Gravitation
NASA Astrophysics Data System (ADS)
Freundlich, Erwin; Brose, Translated by Henry L.; Einstein, Preface by Albert; Turner, Introduction by H. H.
2011-06-01
Introduction; 1. The special theory of relativity as a stepping-stone to the general theory of relativity; 2. Two fundamental postulates in the mathematical formulation of physical laws; 3. Concerning the fulfilment of the two postulates; 4. The difficulties in the principles of classical mechanics; 5. Einstein's theory of gravitation; 6. The verification of the new theory by actual experience; Appendix; Index.
The Excellence of Einstein's Theory of Gravitation.
ERIC Educational Resources Information Center
Dirac, P. A. M.
1979-01-01
This article is adapted from a presentation made in 1978 at the symposium on the Impact of Modern Scientific Ideas on Society organized by UNESCO in Ulm, West Germany. It discusses Einstein's theory of gravitation and how it started a new line of activity for physicists. (HM)
Einstein-Yang-Mills theory: Asymptotic symmetries
NASA Astrophysics Data System (ADS)
Barnich, Glenn; Lambert, Pierre-Henry
2013-11-01
Asymptotic symmetries of the Einstein-Yang-Mills system with or without cosmological constant are explicitly worked out in a unified manner. In agreement with a recent conjecture, one finds a Virasoro-Kac-Moody type algebra not only in three dimensions but also in the four-dimensional asymptotically flat case.
Skyrme-Einstein closed cosmic chiral strings
Rybakov, Yu. P. Ivanova, I. S.
2007-07-15
Within the theory of general relativity, the configuration of a closed string (vortex) characterized by a topological charge of the degree type is described for the Skyrme-Einstein SU (2) chiral model. In the approximation of a large vortex-closure radius (a), a solution to equations of motion is obtained, along with estimates for the vortex energy and radius.
How Einstein Got the Nobel Prize.
ERIC Educational Resources Information Center
Pais, Abraham
1982-01-01
Discusses why the Nobel Committee for Physics waited so long before giving Einstein the Nobel Prize and why they did not award it for relativity, but for the photoelectric effect instead. Focuses on the judgments of leading scientists who made nominations as well as committee members' decisions. (Author/JN)
Quantum metrology with Bose-Einstein condensates
Boixo, Sergio; Datta, Animesh; Davis, Matthew J.; Flammia, Steven T.; Shaji, Anil; Tacla, Alexandre B.; Caves, Carlton M.
2009-04-13
We show how a generalized quantum metrology protocol can be implemented in a two-mode Bose-Einstein condensate of n atoms, achieving a sensitivity that scales better than 1/n and approaches 1/n{sup 3/2} for appropriate design of the condensate.
Particle Correlations in Bose-Einstein Condensates
NASA Astrophysics Data System (ADS)
Jiang, Zhang
The impact of interparticle correlations on the behavior of Bose-Einstein Condensates (BECs) is discussed using two approaches. In the first approach, the wavefunction of a BEC is encoded in the N-particle sector of an extended "catalytic state". Going to a time-dependent interaction picture, we can organize the effective Hamiltonian by powers of N -1/2 . Requiring the terms of order N 1/2 to vanish, we get the Gross-Pitaevskii Equation. Going to the next order, N0, we obtain the number-conserving Bogoliubov approximation. Our approach allows one to stay in the Schrodinger picture and to apply many techniques from quantum optics. Moreover, it is easier to track different orders in the Hamiltonian and to generalize to the multi-component case. In the second approach, I consider a state of N = l x n bosons that is derived by symmetrizing the n-fold tensor product of an arbitrary l-boson state. Particularly, we are interested in the pure state case for l = 2, which we call the Pair-Correlated State (PCS). I show that PCS reproduces the number-conserving Bogoliubov approximation; moreover, it also works in the strong interaction regime where the Bogoliubov approximation fails. For the two-site Bose-Hubbard model, I find numerically that the error (measured by trace distance of the two-particle RDMs) of PCS is less than two percent over the entire parameter space, thus making PCS a bridge between the super uid and Mott insulating phases. Amazingly, the error of PCS does not increase, in the time-dependent case, as the system evolves for longer times. I derive both time-dependent and -independent equations for the ground state and the time evolution of the PCS ansatz. The time complexity of simulating PCS does not depend on N and is linear in the number of orbitals in use. Compared to other methods, e.g, the Jastrow wavefunction, the Gutzwiller wavefunction, and the multi-configurational time-dependent Hartree method, our approach does not require quantum Monte Carlo nor
On the vacuum Einstein equations along curves with a discrete local rotation and reflection symmetry
Korzyński, Mikołaj; Bentivegna, Eloisa E-mail: ian.hinder@aei.mpg.de
2015-08-01
We discuss the possibility of a dimensional reduction of the Einstein equations in S{sup 3} black-hole lattices. It was reported in previous literature that the evolution of spaces containing curves of local, discrete rotation and reflection symmetry (LDRRS) can be carried out via a system of ODEs along these curves. However, 3+1 Numerical Relativity computations demonstrate that this is not the case, and we show analytically that this is due to the presence of a tensorial quantity which is not suppressed by the symmetry. We calculate the term analytically, and verify numerically for an 8-black-hole lattice that it fully accounts for the anomalous results, and thus quantify its magnitude in this specific case. The presence of this term prevents the exact evolution of these spaces via previously-reported methods which do not involve a full 3+1 integration of Einstein's equation.
A Complete Public Archive for the Einstein Imaging Proportional Counter
NASA Technical Reports Server (NTRS)
Helfand, David J.
1996-01-01
Consistent with our proposal to the Astrophysics Data Program in 1992, we have completed the design, construction, documentation, and distribution of a flexible and complete archive of the data collected by the Einstein Imaging Proportional Counter. Along with software and data delivered to the High Energy Astrophysics Science Archive Research Center at Goddard Space Flight Center, we have compiled and, where appropriate, published catalogs of point sources, soft sources, hard sources, extended sources, and transient flares detected in the database along with extensive analyses of the instrument's backgrounds and other anomalies. We include in this document a brief summary of the archive's functionality, a description of the scientific catalogs and other results, a bibliography of publications supported in whole or in part under this contract, and a list of personnel whose pre- and post-doctoral education consisted in part in participation in this project.
Eternal inflation and a thermodynamic treatment of Einstein's equations
Ghersi, José Tomás Gálvez; Geshnizjani, Ghazal; Shandera, Sarah; Piazza, Federico E-mail: ggeshnizjani@perimeterinstitute.ca E-mail: sshandera@perimeterinstitute.ca
2011-06-01
In pursuing the intriguing resemblance of the Einstein equations to thermodynamic equations, most sharply seen in systems possessing horizons, we suggest that eternal inflation of the stochastic type may be a fruitful phenomenon to explore. We develop a thermodynamic first law for quasi-de Sitter space, valid on the horizon of a single observer's Hubble patch and explore consistancy with previous proposals for horizons of various types in dynamic and static situations. We use this framework to demonstrate that for the local observer fluctuations of the type necessary for stochastic eternal inflation fall within the regime where the thermodynamic approach is believed to apply. This scenario is interesting because of suggestive parallels with black hole evaporation.
Bose-Einstein condensation in liquid 4He under pressure
Glyde, Henry R; Omar Diallo, Souleymane; Azuah, Richard T; Kirichek, Oleg; Taylor, Jon W.
2011-01-01
We present neutron scattering measurements of Bose-Einstein condensation, the atomic momen- tum distribution and Final State effects in liquid 4He under pressure. The condensate fraction at low temperature is found to decrease from n0 = 7.25 0.75% at SVP (p 0) to n0 = 3.2 0.75% at pressure p = 24 bar. This indicates an n0 = 3.0% in the liquid at the liquid/solid co-existence line (p = 25.3 bar). The atomic momentum distribution n(k) has high occupation of low k states and differs significantly from a Gaussian (e.g. a classical n(k)). Both n(k) and the Final state function broaden with increasing pressure, reflecting the increased localization of the 4He in space under increased pressure.
Critical collapse in the spherically symmetric Einstein-Vlasov model
NASA Astrophysics Data System (ADS)
Akbarian, Arman; Choptuik, Matthew W.
2014-11-01
We solve the coupled Einstein-Vlasov system in spherical symmetry using direct numerical integration of the Vlasov equation in phase space. Focusing on the case of massless particles we study critical phenomena in the model, finding strong evidence for generic type I behavior at the black hole threshold that parallels what has previously been observed in the massive sector. For differing families of initial data we find distinct critical solutions, so there is no universality of the critical configuration itself. However we find indications of at least a weak universality in the lifetime scaling exponent, which is yet to be understood. Additionally, we clarify the role that angular momentum plays in the critical behavior in the massless case.
NASA Astrophysics Data System (ADS)
Icke, Vincent
1996-03-01
Our Universe consistes of particles, space and time. Ever since Descartes we have known that true emptiness cannot exist; ever since Einstein we have known that space and time are part of the stuff of our world. Efforts to determine the structure of particles go in parallel with the search for the structure of spacetime. Einstein gave us a geometrical answer regarding the structure of spacetime: a distance recipe (Lorentz-Minkowski) suffices. The theory boils down to a patching together of local Lorentz frames into a global whole, which gives it the form of a gauge field theory based on local Lorentz symmetry. On large scales, the Einstein Equation seems to work well. The structure of particles is described by a gauge field. too. On small scales the ‘Standard Model’ seems to work very well. However, we know from Newtonian gravity that the presence of particles must be related to the structure of spacetime. Einstein made a conjecture for the form of this connection using the Newtonian limit of small speeds and weak fields. The right hand side of his equation for the bulk theory of matter (the energy-momentum tensor), is equated to the Einstein tensor from non-Euclidian geometry. But that connection is wrong. The structure of spacetime cannot be equated to the density of particles if we include the Standard Model in the matter tensor. In field theory a potential is not something that can be freely changed by adding an arbitrary scalar term; due to the local (as opposed to global) character of the fields, a potential becomes an entity in itself. Einstein's conjecture runs into profound trouble because the reality of potentials implies that the zero point energy of the vacuum must be included in the Einstein equation. The net result is the appearance of a term equivalent to a cosmological constant A of stupendous size, some 10118 times the critical cosmic density. The crisis due to the zero point fluctuations in the energy-momentum tensor is a clash of titans
NASA Astrophysics Data System (ADS)
Tatum, Brian Shane
This thesis investigates the similarities in the study of time and space in literature and science during the modern period. Specifically, it focuses on the portrayal of time and space within Bram Stoker's Dracula (1897) and Joseph Conrad's Lord Jim (1899-1900), and compares the ideas presented with those later scientifically formulated by Albert Einstein in his special and general theories of relativity (1905-1915). Although both novels precede Einstein's theories, they reveal advanced complex ideas of time and space very similar to those later argued by the iconic physicist. These ideas follow a linear progression including a sense of temporal dissonance, the search for a communal sense of the present, the awareness and expansion of the individual's sense of the present, and the effect of mass on surrounding space. This approach enhances readings of Dracula and Lord Jim, illuminating the fascination with highly refined notions of time and space within modern European culture.
Einstein's steady-state theory: an abandoned model of the cosmos
NASA Astrophysics Data System (ADS)
O'Raifeartaigh, Cormac; McCann, Brendan; Nahm, Werner; Mitton, Simon
2014-09-01
We present a translation and analysis of an unpublished manuscript by Albert Einstein in which he attempted to construct a `steady-state' model of the universe. The manuscript, which appears to have been written in early 1931, demonstrates that Einstein once explored a cosmic model in which the mean density of matter in an expanding universe is maintained constant by the continuous formation of matter from empty space. This model is very different to previously known Einsteinian models of the cosmos (both static and dynamic) but anticipates the later steady-state cosmology of Hoyle, Bondi and Gold in some ways. We find that Einstein's steady-state model contains a fundamental flaw and suggest that it was abandoned for this reason. We also suggest that he declined to explore a more sophisticated version because he found such theories rather contrived. The manuscript is of historical interest because it reveals that Einstein debated between steady-state and evolving models of the cosmos decades before a similar debate took place in the cosmological community.
On the stationary Einstein-Maxwell field equations
NASA Astrophysics Data System (ADS)
Das, A.; Kloster, S.
1980-08-01
The stationary gravitational equations in the presence of the electromagnetic fields, outside charged gravitating sources, are investigated. (i) The action integral of Kramer-Neugebauer-Stephani (K.N.S.) is derived from the Hilbert action integral by using new variational techniques. (ii) It is shown that the classification scheme for the system of partial differential equations of general relativity depends on the coordinate system used. In particular, if orthogonal coordinates are chosen for the associated space then the system of Einstein-Maxwell equations is a hyperbolic one. (iii) The eigenvalues of the Ricci tensor of associated space are expressed in terms of the invariants of stationary electro-gravitational fields. It is proved that if these eigenvalues are equal then the fields must belong to the class of Peres-Israel-Wilson (PIW) solutions. (iv) The global integrability of some of the stationary Einstein-Maxwell equations and the consequent equilibrium conditions of the ''bodies'' are investigated. (v) Boundary value problems for some of the field equations are pursued. It is proved that ω≡ln||g44|| is neither subharmonic nor superharmonic and the boundary value problem for this function does not yield a unique solution in general. A nontrivial solution of the stationary equations with ω≡0 is given. A special boundary value problem is explicitly solved. (vi) The PIW solutions are generated from the charged Kerr-Tomimatsu-Sato-Yamazaki (KTSY) solutions. The complex axially symmetric harmonic functions of these PIW solutions can be obtained from the real axially symmetric harmonic functions of the static Weyl class of electrovac solutions by a complex scale transformation of the coordinates.
Bose-Einstein distribution of money in a free-market economy. II
NASA Astrophysics Data System (ADS)
Kürten, K. E.; Kusmartsev, F. V.
2011-01-01
We argue about the application of methods of statistical mechanics to free economy (Kusmartsev F. V., Phys. Lett. A, 375 (2011) 966) and find that the most general distribution of money or income in a free-market economy has a general Bose-Einstein distribution form. Therewith the market is described by three parameters: temperature, chemical potential and the space dimensionality. Numerical simulations and a detailed analysis of a generic model confirm this finding.
Bose-Einstein correlations and the Dalitz plot of hadronic meson decays
Cuautle, E.; Herrera, G.
1999-10-25
We show that the presence of residual Bose-Einstein correlations may affect the non-resonant contribution of hadronic decays where two identical pions appear in the final state. The distortion of the phase-space of the reaction would be visible in the Dalitz plot. We discuss the decay K{sup +}{yields}{pi}{sup -}{pi}{sup +}{pi}{sup +} which contain two identical pions in the final state.
Dyonic (A)dS black holes in Einstein-Born-Infeld theory in diverse dimensions
NASA Astrophysics Data System (ADS)
Li, Shoulong; Lü, H.; Wei, Hao
2016-07-01
We study Einstein-Born-Infeld gravity and construct the dyonic (A)dS planar black holes in general even dimensions, that carry both the electric charge and magnetic fluxes along the planar space. In four dimensions, the solution can be constructed with also spherical and hyperbolic topologies. We study the black hole thermodynamics and obtain the first law. We also classify the singularity structure.
On the stability of dyons and dyonic black holes in Einstein-Yang-Mills theory
NASA Astrophysics Data System (ADS)
Nolan, Brien C.; Winstanley, Elizabeth
2016-02-01
We investigate the stability of four-dimensional dyonic soliton and black hole solutions of {su}(2) Einstein-Yang-Mills theory in anti-de Sitter space. We prove that, in a neighbourhood of the embedded trivial (Schwarzschild-)anti-de Sitter solution, there exist non-trivial dyonic soliton and black hole solutions of the field equations which are stable under linear, spherically symmetric, perturbations of the metric and non-Abelian gauge field.
Controlling chaos in the Bose-Einstein condensate system of a double lattice
Wang Zhixia Ni Zhengguo; Cong Fuzhong; Liu Xueshen; Chen Lei
2011-02-15
We study the chaotic dynamics in the Bose-Einstein condensate (BEC) system of a double lattice. Chaotic space-time evolution is investigated for the particle number density in a BEC. By changing of the s-wave scattering length with a Feshbach resonance, the chaotic behavior can be well controlled to enter into periodicity. Numerical calculation shows that there is periodic orbit according to the s-wave scattering length only if the maximal Lyapunov exponent of the system is negative.
NASA Astrophysics Data System (ADS)
Holmes, Virginia Iris
2005-03-01
Perhaps motivated by an admiration for Einstein and a desire to identify with him, combined with a majority world-view in opposition to pacifism, skeptics may often question whether Einstein was really a pacifist. They might point to the fact that his dramatic contributions to the field of physics at the beginning of the twentieth century made nuclear weapons possible, as well as his 1939 letter to President Franklin D. Roosevelt urging him to develop such weapons before the Nazis would, as examples of at least an inconsistent stance on pacifism across time on Einstein's part. However, as this paper will show, Einstein's pacifism began early in his life, was a deep-seated conviction that he expressed repeatedly across the years, and was an independent pacifism that flowed from his own responses to events around him and contained some original and impressively forward-thinking elements. Moreover, in calling himself a pacifist, as Einstein did, he defined pacifism in his own terms, not according to the standards of others, and this self-defined pacifism included the flexibility to designate the Nazis as a special case that had to be opposed through the use of military violence, in his view. As early as during his childhood, Einstein already disliked competitive games, because of the necessity of winners and losers, and disliked military discipline. In his late thirties, living in Germany during the First World War with a prestigious academic position in Berlin, yet retaining his identity as a Swiss citizen, Einstein joined a small group of four intellectuals who signed the pacifist ``Appeal to the Europeans'' in response to the militarist ``Manifesto to the Civilized World'' signed by 93 German intellectuals. In private, throughout that War, Einstein repeatedly expressed his disgust and sense of alienation at the ``war-enthusiasm'' sentiment of the majority. In the aftermath of the War, Einstein was involved in a German private commission to investigate German war
An investigation of Bose-Einstein correlations in muon-nucleon interactions at 490 GeV
NASA Astrophysics Data System (ADS)
Adams, M. R.; Aïd, S.; Anthony, P. L.; Baker, M. D.; Bartlett, J.; Bhatti, A. A.; Botterweck, F.; Braun, H. M.; Busza, W.; Conrad, J. M.; Coutrakon, G.; Davisson, R.; Derado, I.; Dhawan, S. K.; Dougherty, W.; Dreyer, T.; Dziunikowska, K.; Eckardt, V.; Ecker, U.; Erdmann, M.; Eskreys, A.; Fang, G.; Figiel, J.; Gebauer, H. J.; Geesaman, D. F.; Gilman, R.; Green, M. C.; Haas, J.; Halliwell, C.; Hanlon, J.; Hantke, D.; Hughes, V. W.; Jackson, H. E.; Jaffe, D. E.; Jancso, G.; Jansen, D. M.; Kaufman, S.; Kennedy, R. D.; Kirk, T.; Kobrak, H. G. E.; Krzywdzinski, S.; Kunori, S.; Lord, J. J.; Lubatti, H. J.; McLeod, D.; Magill, S.; Malecki, P.; Manz, A.; Melanson, H.; Michael, D. G.; Mohr, W.; Montgomery, H. E.; Morfin, J. G.; Nickerson, R. B.; O'Day, S.; Olkiewicz, K.; Osborne, L.; Papavassiliou, V.; Pawlik, B.; Pipkin, F. M.; Ramberg, E. J.; Röser, A.; Ryan, J. J.; Salgado, C. W.; Salvarani, A.; Schellman, H.; Schmitt, M.; Schmitz, N.; Schüler, K. P.; Seyerlein, H. J.; Skuja, A.; Snow, G. A.; Söldner-Rembold, S.; Steinberg, P. H.; Stier, H. E.; Stopa, P.; Swanson, R. A.; Talaga, R.; Tentindo-Repond, S.; Trost, H.-J.; Venkataramania, H.; Wilhelm, M.; Wilkes, J.; Wilson, R.; Wittek, W.; Wolbers, S. A.; Zhao, T.; Fermilab E665 Collaboration
1993-07-01
An investigation of Bose-Einstein correlations amongst like-charged pions produced in muon-nucleon interactions at 490 GeV is presented. On top of a broader enhancement, a steep increase in the correlations at small four-momentum differences between the two pions is observed which may be explained by the contribution from decays of resonances (ϱ-mesons). A two-dimensional analysis discriminates between two different parametrizations of the Bose-Einstein effect, strongly favoring the Lorentz-invariant parametrization over a parametrization based on a Gaussian source distribution in space and time.
Taming the nonlinearity of the Einstein equation.
Harte, Abraham I
2014-12-31
Many of the technical complications associated with the general theory of relativity ultimately stem from the nonlinearity of Einstein's equation. It is shown here that an appropriate choice of dynamical variables may be used to eliminate all such nonlinearities beyond a particular order: Both Landau-Lifshitz and tetrad formulations of Einstein's equation are obtained that involve only finite products of the unknowns and their derivatives. Considerable additional simplifications arise in physically interesting cases where metrics become approximately Kerr or, e.g., plane waves, suggesting that the variables described here can be used to efficiently reformulate perturbation theory in a variety of contexts. In all cases, these variables are shown to have simple geometrical interpretations that directly relate the local causal structure associated with the metric of interest to the causal structure associated with a prescribed background. A new method to search for exact solutions is outlined as well.
Quantum Einstein-de Haas effect
Ganzhorn, Marc; Klyatskaya, Svetlana; Ruben, Mario; Wernsdorfer, Wolfgang
2016-01-01
The classical Einstein-de Haas experiment demonstrates that a change of magnetization in a macroscopic magnetic object results in a mechanical rotation of this magnet. This experiment can therefore be considered as a macroscopic manifestation of the conservation of total angular momentum and energy of electronic spins. Since the conservation of angular momentum is a consequence of a system's rotational invariance, it is valid for an ensemble of spins in a macroscopic ferromaget as well as for single spins. Here we propose an experimental realization of an Einstein-de Haas experiment at the single-spin level based on a single-molecule magnet coupled to a nanomechanical resonator. We demonstrate that the spin associated with the single-molecule magnet is then subject to conservation of total angular momentum and energy, which results in a total suppression of the molecule's quantum tunnelling of magnetization. PMID:27126449
Bose-Einstein condensation of chromium.
Griesmaier, Axel; Werner, Jörg; Hensler, Sven; Stuhler, Jürgen; Pfau, Tilman
2005-04-29
We report on the generation of a Bose-Einstein condensate in a gas of chromium atoms, which have an exceptionally large magnetic dipole moment and therefore underlie anisotropic long-range interactions. The preparation of the chromium condensate requires novel cooling strategies that are adapted to its special electronic and magnetic properties. The final step to reach quantum degeneracy is forced evaporative cooling of 52Cr atoms within a crossed optical dipole trap. At a critical temperature of T(c) approximately 700 nK, we observe Bose-Einstein condensation by the appearance of a two-component velocity distribution. We are able to produce almost pure condensates with more than 50,000 condensed 52Cr atoms.
Quantum Einstein-de Haas effect.
Ganzhorn, Marc; Klyatskaya, Svetlana; Ruben, Mario; Wernsdorfer, Wolfgang
2016-01-01
The classical Einstein-de Haas experiment demonstrates that a change of magnetization in a macroscopic magnetic object results in a mechanical rotation of this magnet. This experiment can therefore be considered as a macroscopic manifestation of the conservation of total angular momentum and energy of electronic spins. Since the conservation of angular momentum is a consequence of a system's rotational invariance, it is valid for an ensemble of spins in a macroscopic ferromaget as well as for single spins. Here we propose an experimental realization of an Einstein-de Haas experiment at the single-spin level based on a single-molecule magnet coupled to a nanomechanical resonator. We demonstrate that the spin associated with the single-molecule magnet is then subject to conservation of total angular momentum and energy, which results in a total suppression of the molecule's quantum tunnelling of magnetization.
Axions: Bose Einstein condensate or classical field?
NASA Astrophysics Data System (ADS)
Davidson, Sacha
2015-05-01
The axion is a motivated dark matter candidate, so it would be interesting to find features in Large Scale Structures specific to axion dark matter. Such features were proposed for a Bose Einstein condensate of axions, leading to confusion in the literature (to which I contributed) about whether axions condense due to their gravitational interactions. This note argues that the Bose Einstein condensation of axions is a red herring: the axion dark matter produced by the misalignment mechanism is already a classical field, which has the distinctive features attributed to the axion condensate (BE condensates are described as classical fields). This note also estimates that the rate at which axion particles condense to the field, or the field evaporates to particles, is negligible.
NASA Astrophysics Data System (ADS)
Hecht, Eugene
2011-06-01
The equivalence of mass m and rest-energy E0 is one of the great discoveries of all time. Despite the current wisdom, Einstein did not derive this relation from first principles. Having conceived the idea in the summer of 1905 he spent more than 40 years trying to prove it. We briefly examine all of Einstein's conceptual demonstrations of E0=mc2, focusing on their limitations and his awareness of their shortcomings. Although he repeatedly confirmed the efficacy of E0=mc2, he never constructed a general proof. Leaving aside that it continues to be affirmed experimentally, a rigorous proof of the mass-energy equivalence is probably beyond the purview of the special theory.
Astrophysical Bose-Einstein condensates and superradiance
NASA Astrophysics Data System (ADS)
Kühnel, Florian; Rampf, Cornelius
2014-11-01
We investigate gravitational analogue models to describe slowly rotating objects (e.g., dark-matter halos, or boson stars) in terms of Bose-Einstein condensates, trapped in their own gravitational potentials. We begin with a modified Gross-Pitaevskii equation, and show that the resulting background equations of motion are stable, as long as the rotational component is treated as a small perturbation. The dynamics of the fluctuations of the velocity potential are effectively governed by the Klein-Gordon equation of an "Eulerian metric," where we derive the latter by the use of a relativistic Lagrangian extrapolation. Superradiant scattering on such objects is studied. We derive conditions for its occurrence and estimate its strength. Our investigations might give an observational handle to phenomenologically constrain Bose-Einstein condensates.
How Einstein Discovered E0=mc2
NASA Astrophysics Data System (ADS)
Hecht, Eugene
2012-02-01
This paper traces Einstein's discovery of "the equivalence of mass [m] and energy [E0]." He came to that splendid insight in 1905 while employed by the Bern Patent Office, at which time he was not an especially ardent reader of physics journals. How then did the young savant, working outside of academia in semi-isolation, realize that these two seemingly disparate concepts were actually "identical"? Until now little attention has been given to exploring the physics that guided his thinking in this remarkable endeavor. That work culminated (1907) in the equation E0=mc2, where E0 is "rest energy" and m is "invariant mass." Despite claims to the contrary, Einstein did not write this equation, or its ambiguous variant, E =mc2, in 1905. Furthermore, we will propose a compelling reason for his otherwise inexplicable caution. This paper is meant to help clarify the contemporary literature in the service of an informed pedagogy.
Taming the nonlinearity of the Einstein equation.
Harte, Abraham I
2014-12-31
Many of the technical complications associated with the general theory of relativity ultimately stem from the nonlinearity of Einstein's equation. It is shown here that an appropriate choice of dynamical variables may be used to eliminate all such nonlinearities beyond a particular order: Both Landau-Lifshitz and tetrad formulations of Einstein's equation are obtained that involve only finite products of the unknowns and their derivatives. Considerable additional simplifications arise in physically interesting cases where metrics become approximately Kerr or, e.g., plane waves, suggesting that the variables described here can be used to efficiently reformulate perturbation theory in a variety of contexts. In all cases, these variables are shown to have simple geometrical interpretations that directly relate the local causal structure associated with the metric of interest to the causal structure associated with a prescribed background. A new method to search for exact solutions is outlined as well. PMID:25615299
Ritz, Einstein, and the Emission Hypothesis
NASA Astrophysics Data System (ADS)
Martínez, Alberto A.
. Just as Albert Einstein's special theory of relativity was gaining acceptance around 1908, the young Swiss physicist Walter Ritz advanced a competing though preliminary emission theory that sought to explain the phenomena of electrodynamics on the assumption that the speed of light depends on the motion of its source. I survey Ritz's unfinished work in this area and review the reasons why Einstein and other physicists rejected Ritz's and other emission theories. Since Ritz's emission theory attracted renewed attention in the 1960s, I discuss how the earlier observational evidence was misconstrued as telling against it more conclusively than actually was the case. Finally, I contrast the role played by evidence against Ritz's theory with other factors that led to the early rejection of his approach.
Taming the Nonlinearity of the Einstein Equation
NASA Astrophysics Data System (ADS)
Harte, Abraham I.
2014-12-01
Many of the technical complications associated with the general theory of relativity ultimately stem from the nonlinearity of Einstein's equation. It is shown here that an appropriate choice of dynamical variables may be used to eliminate all such nonlinearities beyond a particular order: Both Landau-Lifshitz and tetrad formulations of Einstein's equation are obtained that involve only finite products of the unknowns and their derivatives. Considerable additional simplifications arise in physically interesting cases where metrics become approximately Kerr or, e.g., plane waves, suggesting that the variables described here can be used to efficiently reformulate perturbation theory in a variety of contexts. In all cases, these variables are shown to have simple geometrical interpretations that directly relate the local causal structure associated with the metric of interest to the causal structure associated with a prescribed background. A new method to search for exact solutions is outlined as well.
Schrodinger Leopards in Bose-Einstein Condensates
NASA Astrophysics Data System (ADS)
Carr, Lincoln D.; Dounas-Frazer, Dimitri R.
2008-03-01
We present the complex quantum dynamics of vortices in Bose-Einstein condensates in a double well via exact diagonalization of a discretized Hamiltonian. When the barrier is high, vortices evolve into macroscopic superposition (NOON) states of a vortex in either well -- a Schrodinger cat with spots. Such Schrodinger leopard states are more robust than previously proposed NOON states, which only use two single particle modes of the double well potential.
Bose-Einstein condensation of cesium.
Weber, Tino; Herbig, Jens; Mark, Michael; Nägerl, Hanns-Christoph; Grimm, Rudolf
2003-01-10
Bose-Einstein condensation of cesium atoms is achieved by evaporative cooling using optical trapping techniques. The ability to tune the interactions between the ultracold atoms by an external magnetic field is crucial to obtain the condensate and offers intriguing features for potential applications. We explore various regimes of condensate self-interaction (attractive, repulsive, and null interaction strength) and demonstrate properties of imploding, exploding, and non-interacting quantum matter. PMID:12471267
Bose-Einstein correlations from 'within'
Utyuzh, O. V.; Wilk, G.; Wlodarczyk, Z.
2006-04-11
We describe an attempt to model numerically Bose-Einstein correlations (BEC) from 'within', i.e., by using them as the most fundamental ingredient of some Monte Carlo event generator (MC) rather than considering them as a kind of (more or less important, depending on the actual situation) 'afterburner', which inevitably changes original physical content of the MC code used to model multiparticle production process.
Inhomogeneous Einstein-Rosen string cosmology
NASA Astrophysics Data System (ADS)
Clancy, Dominic; Feinstein, Alexander; Lidsey, James E.; Tavakol, Reza
1999-08-01
Families of anisotropic and inhomogeneous string cosmologies containing non-trivial dilaton and axion fields are derived by applying the global symmetries of the string effective action to a generalized Einstein-Rosen metric. The models exhibit a two-dimensional group of Abelian isometries. In particular, two classes of exact solutions are found that represent inhomogeneous generalizations of the Bianchi type VIh cosmology. The asymptotic behavior of the solutions is investigated and further applications are briefly discussed.
Einstein's Revolutionary Light--Quantum Hypothesis
NASA Astrophysics Data System (ADS)
Stuewer, R. H.
2006-03-01
Albert Einstein's light-quantum paper was the only one of his great papers of 1905 that he himself called ``very revolutionary''. I sketch his arguments for light quanta, his analysis of the photoelectric effect, and his introduction of the wave-particle duality into physics in 1909. I show that Robert Andrews Millikan, in common with almost all physicists at the time, rejected Einstein's light-quantum hypothesis as an interpretation of his photoelectric-effect experiments of 1915. I then trace the complex experimental and theoretical route that Arthur Holly Compton followed between 1916 and 1922 that led to his discovery of the Compton effect, a discovery that Peter Debye also made virtually simultaneously and independently. Compton's discovery, however, was challenged on experimental grounds by William Duane and on theoretical grounds by Niels Bohr in the Bohr--Kramers--Slater theory of 1924, and only after that theory was disproved experimentally the following year by Walther Bothe and Hans Geiger in Berlin and by Compton and Alfred W. Simon in Chicago was Einstein's light-quantum hypothesis generally accepted by physicists.
Einstein and the history of general relativity
Howard, D.; Stachel, J.
1989-01-01
This book is a collection of essays by the authors and other people that deal with scientific opinions that led Einstein and his contemporaries to their views of general relativity. Some of the essays explore Einstein's passage from the special theory through a sequence of gravitational theories to the discovery of the field equations of the grand theory in November 1915. Two other essays discuss Einstein's public and private exchanges with Max Abraham and Tullio Levi-Civita in 1913 and 1914. A sympathetic picture of H.A. Lorentz's reaction to the general theory of relativity is included, and a careful and insightful essay on the early understanding of the Schwarzschild-Droste solution to the field equations of general relativity is presented. One paper presents a discussion on the state of the enterprise of general relativity between 1925 and 1928, and a short essay details the history of steps toward quantum gravitational through canonical quantization. A discussion of the history of derivations of the geodesic equation of motion from the field equation and conservation laws of the general theory is presented. The early history of geometrical unified field theories is included.
Stellar coronae from Einstein - Observations and theory
NASA Technical Reports Server (NTRS)
Rosner, R.; Vaiana, G. S.
1980-01-01
Einstein Observatory observations of stellar X-ray emission are presented and their implications for the formation of stellar coronae and the problem of stellar angular momentum loss are discussed. Solar coronal X-ray observations and observations of stellar coronae made prior to Einstein are reviewed, and it is noted that they already suggest that the standard theory of acoustic coronal heating is inadequate. The principal results of the Einstein/CfA stellar survey are summarized, with attention given to variations of the level of X-ray flux detected along the main sequence, the decline of X-ray flux with increasing age of giants and supergiants, and indications of a large range of X-ray emission levels within a given type, which are clearly incompatible with models for acoustic flux generation. A new theory to explain stellar coronae and hence X-ray emission from them is then proposed in which stellar magnetic fields play the key role in determining the level of coronal emission, and the modulation of the surface magnetic flux level and the level of stressing of surface magnetic fields essentially determine the variation of mean coronal activity in the H-R diagram.
On static Poincaré-Einstein metrics
NASA Astrophysics Data System (ADS)
Galloway, Gregory J.; Woolgar, Eric
2015-06-01
The classification of solutions of the static vacuum Einstein equations, on a given closed manifold or an asymptotically flat one, is a long-standing and much-studied problem. Solutions are characterized by a complete Riemannian n-manifold ( M, g) and a positive function N, called the lapse. We study this problem on Asymptotically Poincaré-Einstein n-manifolds, n ≥ 3, when the conformal boundary-at-infinity is either a round sphere, a flat torus or smooth quotient thereof, or a compact hyperbolic manifold. Such manifolds have well-defined Wang mass, and are time-symmetric slices of static, vacuum, asymptotically anti-de Sitter spacetimes. By integrating a mildly generalized form of an identity used by Lindblom, Shen, Wang, and others, we give a mass formula for such manifolds. There are no solutions with positive mass. In consequence, we observe that either the lapse is trivial and ( M, g) is Poincaré-Einstein or the Wang mass is negative, as in the case of time symmetric slices of the AdS soliton. As an application, we use the mass formula to compute the renormalized volume of the warped product ( X, γ) ≃ ( M 3 , g) × N 2 ( S 1 , dt 2).
Geometrical properties of an internal local octonionic space in curved space time
Marques, S.; Oliveira, C.G.
1986-04-01
A geometrical treatment on a flat tangent space local to a generalized complex, quaternionic, and octonionic space-time is constructed. It is shown that it is possible to find an Einstein-Maxwell-Yang-Mills correspondence in this generalized (Minkowskian) tangent space. 9 refs.
The Unfinished Revolution: Einstein's revenge
NASA Astrophysics Data System (ADS)
Beichler, James
2007-04-01
Thomas Kuhn defined the characteristics of scientific revolutions based upon his knowledge of the first and second Scientific Revolutions. He concluded that such revolutions are the result of crises in science. However, he missed some important clues of how revolutions develop. Instead of looking at crises, we should look at the major trends in scientific and human thought prior to the revolutions and then we could gain a better understanding of how scientific revolutions emerge from the normal course of scientific evolution. Instead of defining revolutions by the crises that precede them, revolutions actually emerge from the successes of previous science while each revolution contains the seeds for the next revolution that follows. These seeds eventually grow into the crises that trigger revolutions. Under these circumstances, it can be shown that the space-time revolution of relativity theory was never completed, thus laying the foundations for the next revolution in science. Knowing this, we can determine if we have we already entered the pre-revolutionary period of the Third Scientific Revolution.
Superfluidity of Bose—Einstein condensates in ultracold atomic gases
NASA Astrophysics Data System (ADS)
Zhu, Qi-Zhong; Wu, Biao
2015-05-01
Liquid helium 4 had been the only bosonic superfluid available in experiments for a long time. This situation was changed in 1995, when a new superfluid was born with the realization of the Bose-Einstein condensation in ultracold atomic gases. The liquid helium 4 is strongly interacting and has no spin; there is almost no way to change its parameters, such as interaction strength and density. The new superfluid, Bose-Einstein condensate (BEC), offers various advantages over liquid helium. On the one hand, BEC is weakly interacting and has spin degrees of freedom. On the other hand, it is convenient to tune almost all the parameters of a BEC, for example, the kinetic energy by spin-orbit coupling, the density by the external potential, and the interaction by Feshbach resonance. Great efforts have been devoted to studying these new aspects, and the results have greatly enriched our understanding of superfluidity. Here we review these developments by focusing on the stability and critical velocity of various superfluids. The BEC systems considered include a uniform superfluid in free space, a superfluid with its density periodically modulated, a superfluid with artificially engineered spin-orbit coupling, and a superfluid of pure spin current. Due to the weak interaction, these BEC systems can be well described by the mean-field Gross-Pitaevskii theory and their superfluidity, in particular critical velocities, can be examined with the aid of Bogoliubov excitations. Experimental proposals to observe these new aspects of superfluidity are discussed. Project supported by the National Basic Research Program of China (Grant Nos. 2013CB921903 and 2012CB921300) and the National Natural Science Foundation of China (Grant Nos. 11274024, 11334001, and 11429402).
Extended Horava gravity and Einstein-aether theory
Jacobson, Ted
2010-05-15
Einstein-aether theory is general relativity coupled to a dynamical, unit timelike vector. If this vector is restricted in the action to be hypersurface orthogonal, the theory is identical to the IR limit of the extension of Horava gravity proposed by Blas, Pujolas and Sibiryakov. Hypersurface orthogonal solutions of Einstein-aether theory are solutions to the IR limit of this theory, hence numerous results already obtained for Einstein-aether theory carry over.
Mass variation formulae for Einstein-Yang-Mills-Higgs and Einstein-dilaton black holes
NASA Astrophysics Data System (ADS)
Heusler, Markus; Straumann, Norbert
1993-09-01
We consider the ``first law'' of black hole physics for stationary Einstein-Yang-Mills-Higgs and Einstein-dilaton theories. It is shown that the mass variation formula involves only global quantities and surface terms. Our results hold for arbitrary gauge groups and any structure of the Higgs field multiplets. For purely magnetic field configurations, the extra horizon integrals vanish and the variation of the mass can be expressed in terms of the usual vacuum contributions and additional surface integrals at spacelike infinity.
Einstein-Podolsky-Rosen Correlations via Dissociation of a Molecular Bose-Einstein Condensate
Kheruntsyan, K.V.; Drummond, P.D.; Olsen, M.K.
2005-10-07
Recent experimental measurements of atomic intensity correlations through atom shot noise suggest that atomic quadrature phase correlations may soon be measured with a similar precision. We propose a test of local realism with mesoscopic numbers of massive particles based on such measurements. Using dissociation of a Bose-Einstein condensate of diatomic molecules into bosonic atoms, we demonstrate that strongly entangled atomic beams may be produced which possess Einstein-Podolsky-Rosen (EPR) correlations in field quadratures in direct analogy to the position and momentum correlations originally considered by EPR.
Bose-Einstein condensation of spin-1 field in an Einstein universe
NASA Astrophysics Data System (ADS)
Altaie, M. B.; Malkawi, Ehab
2000-10-01
In this paper we investigate the Bose-Einstein condensation of massive spin-1 particles in an Einstein universe. The system is considered under relativistic conditions taking into consideration the possibility of particle-antiparticle pair production. An exact expression for the charge density is obtained, then certain approximations are employed in order to obtain the solutions in closed form. A discussion of the approximations employed in this and other work is given. The effects of finite-size and spin-curvature coupling are emphasized.
Composite structure of vortices in two-component Bose-Einstein condensate
NASA Astrophysics Data System (ADS)
Ivashin, Anatoly P.; Poluektov, Yuri M.
2015-10-01
In contrast to one-component Bose-Einstein condensate case, the vortices in two-component condensate can have various complicated structures. The vortices in a space-homogeneous Bose-Einstein condensate have been studied in this paper. It is shown that the vortex structure is described by three dimensionless parameters. This is totally different from the usual one-component condensate case,where an isolated vortex is described by a parameterless dimensionless equation. The two-component vortex structure strongly depends on the sign of "interaction" constant of the components. A few types of vortices with different qualitative structure are explored. We show that the "super-density vortices" can exist, when the "interaction" constant is positive. The "super-density vortices" have the near-axis density greater than the equilibrium density of a homogeneous space Bose-Einstein condensate. We also show that the vortices with opposite direction of the condensate component rotation near the axis and far off the axis can exist.
Exact Solutions to the Einstein-Maxwell Equations Describing Wormholes and Handles
NASA Astrophysics Data System (ADS)
Khlestkov, Yu. A.; Sukhanova, L. A.
2016-06-01
On the basis of the exact solutions to the non-stationary spherically symmetric Einstein and Maxwell equations for dust matter and radial electromagnetic field, a model of a wormhole with the pulsating in time inner world and two static throats has been developed. It has been shown that such a wormhole with an arbitrary radius of the Gaussian curvature can connect both two different asymptotically flat space-times and two regions of the selfsame space-time (handles of the Wheeler type). The problem of the fulfilment of the energy conditions in this wormhole has been investigated, as well as the problem of its traversability investigation has been set.
Mechanocaloric and thermomechanical effects in Bose-Einstein-condensed systems
Marques, G.C.; Bagnato, V.S.; Muniz, S.R.; Spehler, D.
2004-05-01
In this paper we extend previous hydrodynamic equations, governing the motion of Bose-Einstein-condensed fluids, to include temperature effects. This allows us to analyze some differences between a normal fluid and a Bose-Einstein-condensed one. We show that, in close analogy with superfluid {sup 4}He, a Bose-Einstein-condensed fluid exhibits the mechanocaloric and thermomechanical effects. In our approach we can explain both effects without using the hypothesis that the Bose-Einstein-condensed fluid has zero entropy. Such ideas could be investigated in existing experiments.
An efficient numerical method for computing dynamics of spin F = 2 Bose-Einstein condensates
Wang Hanquan
2011-07-01
In this paper, we extend the efficient time-splitting Fourier pseudospectral method to solve the generalized Gross-Pitaevskii (GP) equations, which model the dynamics of spin F = 2 Bose-Einstein condensates at extremely low temperature. Using the time-splitting technique, we split the generalized GP equations into one linear part and two nonlinear parts: the linear part is solved with the Fourier pseudospectral method; one of nonlinear parts is solved analytically while the other one is reformulated into a matrix formulation and solved by diagonalization. We show that the method keeps well the conservation laws related to generalized GP equations in 1D and 2D. We also show that the method is of second-order in time and spectrally accurate in space through a one-dimensional numerical test. We apply the method to investigate the dynamics of spin F = 2 Bose-Einstein condensates confined in a uniform/nonuniform magnetic field.
Inhomogeneous dust collapse in 5D Einstein-Gauss-Bonnet gravity
Jhingan, S.; Ghosh, Sushant G.
2010-01-15
We consider a Lemaitre-Tolman-Bondi type space-time in Einstein gravity with the Gauss-Bonnet combination of quadratic curvature terms, and present an exact solution in closed form. It turns out that the presence of the coupling constant of the Gauss-Bonnet terms {alpha}>0 completely changes the causal structure of the singularities from the analogous general relativistic case. The gravitational collapse of inhomogeneous dust in the five-dimensional Gauss-Bonnet extended Einstein equations leads to formation of a massive, but weak, timelike singularity which is forbidden in general relativity. Interestingly, this is a counterexample to three conjectures, viz., cosmic censorship conjecture, hoop conjecture, and Seifert's conjecture.
New experimental results on cosmic gravitational effects and the centenary of Einstein's equation
NASA Astrophysics Data System (ADS)
Unnikrishnan, C. S.
As one celebrates the centennial triumph of the general theory of relativity (GTR), Einstein's theory of gravity, it is appropriate to review and assess the experimental foundations of the theory in the context of what we know about matter in the universe, a knowledge that did not exist when GTR was formulated. A worldview consistent with and rigorously based on experimental evidence indeed demands a paradigm change and theoretical revision. The new theory of dynamics and relativity is Cosmic Relativity, with both absolute space and absolute time of a preferred cosmic frame, and it implies a modified GTR on its new and deeper foundation. Supporting results from laboratory experiments on the relative one-way velocity of light and the direct gravitational action of the cosmic matter on dynamics are discussed, demanding a modified equation of relativistic gravitation, aptly called the Centenary Einstein's equation.
Inhomogeneous dust collapse in 5D Einstein-Gauss-Bonnet gravity
NASA Astrophysics Data System (ADS)
Jhingan, S.; Ghosh, Sushant G.
2010-01-01
We consider a Lemaitre-Tolman-Bondi type space-time in Einstein gravity with the Gauss-Bonnet combination of quadratic curvature terms, and present an exact solution in closed form. It turns out that the presence of the coupling constant of the Gauss-Bonnet terms α>0 completely changes the causal structure of the singularities from the analogous general relativistic case. The gravitational collapse of inhomogeneous dust in the five-dimensional Gauss-Bonnet extended Einstein equations leads to formation of a massive, but weak, timelike singularity which is forbidden in general relativity. Interestingly, this is a counterexample to three conjectures, viz., cosmic censorship conjecture, hoop conjecture, and Seifert’s conjecture.
Dynamics of three noncorotating vortices in Bose-Einstein condensates.
Koukouloyannis, V; Voyatzis, G; Kevrekidis, P G
2014-04-01
In this work we use standard Hamiltonian-system techniques in order to study the dynamics of three vortices with alternating charges in a confined Bose-Einstein condensate. In addition to being motivated by recent experiments, this system offers a natural vehicle for the exploration of the transition of the vortex dynamics from ordered to progressively chaotic behavior. In particular, it possesses two integrals of motion, the energy (which is expressed through the Hamiltonian H) and the angular momentum L of the system. By using the integral of the angular momentum, we reduce the system to a 2-degrees-of-freedom one with L as a parameter and reveal the topology of the phase space through the method of Poincaré surfaces of section. We categorize the various motions that appear in the different regions of the sections and we study the major bifurcations that occur to the families of periodic motions of the system. Finally, we correspond the orbits on the surfaces of section to the real space motion of the vortices in the plane.
Bose-Einstein Condensation in Extended Microgravity
NASA Astrophysics Data System (ADS)
Scharringhausen, Marco; Quantus Team; Rasel, Ernst Maria
2012-07-01
The setup and the envisaged experiment timeline of the QUANTUS-III experiment onboard a sounding rocket to be started in the near future are presented. The major intention of QUANTUS-III is the stable generation of a number of Bose-Einstein condensates as a source for atom interferometry during several minutes of microgravity onboard the sounding rocket. Later missions aim at the realization of atom interferoemeters as precursor satellite missions. These condesates will be generated serially, allowing a large number of repeatable tests. Within such Bose-Einstein condensates, millions of atoms lose their identity and can be described by a single macroscopic wave function. During the expansion over several seconds, the atoms form a giant coherent matter wave that is delocalized on a millimeter scale, which represents a promising source for matter-wave interferometry to test the universality of free fall with quantum matter. Cold quantum gases and, in particular, Bose-Einstein condensates represent a new state of matter which is nowadays established in many laboratories. They offer unique insights into a broad range of fundamental physics as well as prospects for novel quantum sensors. Microgravity will substantially extend the science of quantum gases towards nowadays inaccessible regimes at lowest temperatures, to macroscopic dimensions, and to unequalled durations of unperturbed evolution of these distinguished quantum objects. Right now, the QUANTUS-III experiment is in the development phase, taking heritage from QUANTUS-I and QUANTUS-II. Major components of the engineering model are available. Boundary conditions of the rocket, requirements of the experiment and interface considerations are presented. This include laser stabilization, vacuum technology and magnetic shielding. The planned trajectory of the rocket will have an apogee of 200 - 300 km and a total microgravity time of 4 - 7 minutes, both depending on the total experiment mass.
Bose-Einstein condensation of sodium atoms
NASA Astrophysics Data System (ADS)
Mewes, Marc-Oliver
1997-10-01
Bose-Einstein Condensation in an ultracold gas of neutral sodium atoms has been observed and studied. This was achieved utilizing a combination of laser cooling techniques, magnetic trapping and evaporative cooling. A novel tightly confining dc magnetic trap was developed and demonstrated. This trap combines tight confinement with excellent optical access. Evaporative cooling in this trap produced Bose condensates of 5× 106 atoms, a tenfold improvement over previous results. The Bose-Einstein phase transition was studied and characterized by mapping out the condensed fraction as a function of temperature across the transition point. The characteristic mean-field interaction of particles in the condensate was investigated. Collective excitations of a dilute Bose condensate have been observed. These excitations are analogous to phonons in superfluid helium. The frequencies of the lowest modes were studied for a temperature close to 0 K and compared with theoretical predictions based on mean-field theory. The characteristic damping of one of the modes was measured and compared to damping of 'sound waves' in an ultra-cold gas above the Bose-Einstein transition. We have also demonstrated an output coupler for Bose condensed atoms in a magnetic trap. With short rf pulses Bose condensates were put into a superposition of trapped and untrapped hyperfine states. By varying the rf amplitude we could adjust the fraction of outcoupled atoms between 0 and 100%. This source produces pulses of coherent atoms and can be regarded as a pulsed 'atom laser'. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)
NASA Astrophysics Data System (ADS)
Winterberg, Friedwardt
2008-04-01
It was Albert Einstein who for the first time changed our view of the universe to be a non-euclidean curved space-time. And it was Wernher von Braun who blazed the trail to take us into this universe, leaving for the first time the gravitational field of our planet earth, with the landing a man on the moon the greatest event in human history. Both these great physicists did this on the shoulders of giants. Albert Einstein on the shoulders of his landsman, the mathematician Bernhard Riemann, and Wernher von Braun on the shoulders of Goddard and Oberth. Both Einstein and von Braun made a Faustian pact with the devil, von Braun by accepting research funds from Hitler, and Einstein by urging Roosvelt to build the atom bomb (against Hitler). Both of these great men later regretted the use of their work for the killing of innocent bystanders, even though in the end the invention of nuclear energy and space flight is for the benefit of man. Their example serves as a warning for all of us. It can be formulated as follows: ``Can I in good conscience accept research funds from the military to advance scientific knowledge, for weapons developed against an abstract enemy I never have met in person?'' Weapons if used do not differentiate between the scientist, who invented these weapons, and the non-scientist.
Wormholes in Einstein-Born-Infeld theory
Richarte, Martin G.; Simeone, Claudio
2009-11-15
Spherically symmetric thin-shell wormholes are studied within the framework of Einstein-Born-Infeld theory. We analyze the exotic matter content, and find that for certain values of the Born-Infeld parameter the amount of exotic matter on the shell can be reduced in relation to the Maxwell case. We also examine the mechanical stability of the wormhole configurations under radial perturbations preserving the spherical symmetry. In addition, in the Appendix the repulsive or attractive character of the wormhole geometries is briefly discussed.
Universality of the Einstein theory of gravitation
NASA Astrophysics Data System (ADS)
Kijowski, Jerzy
2016-08-01
We show that generalizations of general relativity theory, which consist in replacing the Hilbert Lagrangian LHilbert = 1 16π|g|R by a generic scalar density L = L(gμν,Rμνκλ) depending upon the metric gμν and the curvature tensor Rμνκλ, are equivalent to the conventional Einstein theory for a (possibly) different metric tensor g˜μν and (possibly) a different set of matter fields. The simple proof of this theorem relies on a new approach to variational problems containing metric and connection.
Extragalactic counterparts to Einstein slew survey sources
NASA Technical Reports Server (NTRS)
Schachter, Jonathan F.; Elvis, Martin; Plummer, David; Remillard, Ron
1992-01-01
The Einstein slew survey consists of 819 bright X-ray sources, of which 636 (or 78 percent) are identified with counterparts in standard catalogs. The importance of bright X-ray surveys is stressed, and the slew survey is compared to the Rosat all sky survey. Statistical techniques for minimizing confusion in arcminute error circles in digitized data are discussed. The 238 slew survey active galactic nuclei, clusters, and BL Lacertae objects identified to date and their implications for logN-logS and source evolution studies are described.
Lincoln, Don
2016-07-12
One of the most non-intuitive physics theories ever devised is Einsteinâs Theory of Special Relativity, which claim such crazy-sounding things as two people disagreeing on such familiar concepts as length and time. In this video, Fermilabâs Dr. Don Lincoln shows that every single day particle physicists prove that moving clocks tick more slowly than stationary ones. He uses an easy to understand example of particles that move for far longer distances than you would expect from combining their velocity and stationary lifetime.
Varying G. [in Einstein gravitation theory
NASA Technical Reports Server (NTRS)
Canuto, V.; Hsieh, S.-H.; Owen, J. R.
1979-01-01
The problem of the variation of the gravitational constant with cosmological time is critically analyzed. Since Einstein's equation does not allow G to vary on any time scale, no observational data can be analyzed within the context of the standard theory. The recently proposed scale covariant theory, which allows (but does not demand) G to vary, and which has been shown to have passed several standard cosmological tests, is employed to discuss some recent nonnull observational results which indicate a time variation of G.
Einstein observations of active galaxies and quasars
NASA Technical Reports Server (NTRS)
Schreier, E. J.
1979-01-01
The radio galaxies Centaurus A and Signus B are discussed. In both these sources, a comparison of the radio and imaged X-ray flux is allowed for the measurement of the magnetic fields. Einstein observations of quasars are discussed. The number of known X-ray emitting QSO's was increased from 3 to 22 and the distances where these QSO's were seen to correspond to an age of 15 billion years. It was shown that these quasars contributed significantly to the X-ray background.
Bose-Einstein condensation in complex networks.
Bianconi, G; Barabási, A L
2001-06-11
The evolution of many complex systems, including the World Wide Web, business, and citation networks, is encoded in the dynamic web describing the interactions between the system's constituents. Despite their irreversible and nonequilibrium nature these networks follow Bose statistics and can undergo Bose-Einstein condensation. Addressing the dynamical properties of these nonequilibrium systems within the framework of equilibrium quantum gases predicts that the "first-mover-advantage," "fit-get-rich," and "winner-takes-all" phenomena observed in competitive systems are thermodynamically distinct phases of the underlying evolving networks.
From the Classroom to Washington: Einsteins on Education Reform
ERIC Educational Resources Information Center
Hughes, Kent H., Ed.; Byers, Elizabeth A., Ed.
2010-01-01
The Woodrow Wilson International Center for Scholars was delighted to host a group of current and former Albert Einstein Distinguished Educator Fellows as they celebrated the 20th anniversary of the fellowship program. Outstanding math and science teachers in America's K-12 schools, the Einstein Fellows spend a year (or sometimes two) working on…
[Photoeffects, Einstein's light quanta and the history of their acceptance].
Wiederkehr, Karl Heinrich
2006-01-01
It is generally supposed, that the discovery of the efficacy-quantum by Planck was the impetus to Einstein's hypothesis of lightquanta. With its help Einstein could explain the external light-electrical effect. But even years before Einstein had worked at the photoeffect and already made experiments on it. For that reason the article gives a short survey about the history of the lightelectric effects. Lenard's basical work about the release of the photoelectrons is dealt with in detail, without which Einstein would scarcely have found his lightquanta. Furthermore it is shown how difficult it was for the physicists to give up--at least partially--the traditional view of the undulation-nature of light, and how they searched to explain the great energies of the photoelectrons. On the other side it is set forth how Einstein's formula of lightquanta was gradually confirmed. The tragical development of Einstein's personal relations with Johannes Stark and Philipp Lenard are briefly described. Stark was one of the few who supported Einstein's ideas at the beginning. Only with the Compton-effect, which could only be quantitatively interpreted by means of lightquanta and the special theory of relativity 1923, the way was free for the general acceptance of the lightquanta. Einstein did not agree to the obtained dualism of undulation and corpuscle; he had a different solution in mind about the fusion of the two forms of appearance of light. PMID:17338401
Quantum Mechanics of the Einstein-Hopf Model.
ERIC Educational Resources Information Center
Milonni, P. W.
1981-01-01
The Einstein-Hopf model for the thermodynamic equilibrium between the electromagnetic field and dipole oscillators is considered within the framework of quantum mechanics. Both the wave and particle aspects of the Einstein fluctuation formula are interpreted in terms of the fundamental absorption and emission processes. (Author/SK)
A Demonstration of Einstein's Equivalence of Gravity and Acceleration
ERIC Educational Resources Information Center
Newburgh, Ronald
2008-01-01
In 1907, Einstein described a "Gedankenexperiment" in which he showed that free fall in a gravitational field is indistinguishable from a body at rest in an elevator accelerated upwards in zero gravity. This paper describes an apparatus, which is simple to make and simple to operate, that acts as an observable footnote to Einstein's example. It…
International Conference on Relativistic Astrophysics and Cosmology -- Einstein's Legacy
NASA Astrophysics Data System (ADS)
2005-09-01
100 years ago Albert Einstein published three seminal papers on the theories of special relativity, of the photoelectric effect and of Brownian motion, which made the world call the year 1905 the miraculous year. Together with Einstein's theory of general relativity fundamental building blocks were provided for modern astrophysics and cosmology and can thus be considered as a true legacy to mankind.
NASA Technical Reports Server (NTRS)
Elachi, Charles
1993-01-01
The advent of the capability to conduct space-based measurements has revolutionized the study of the Earth, the planetary system and the astrophysical universe. The resultant knowledge has yielded insights into the management of our planet's resources and provides intellectual enrichment for our civilization. New investigation techniques hold promise for extending the scope of space science to address topics in fundamental physics such as gravitational waves and certain aspects of Einstein's Theory of General Relativity.
Photon condensation: A new paradigm for Bose-Einstein condensation
NASA Astrophysics Data System (ADS)
Rajan, Renju; Ramesh Babu, P.; Senthilnathan, K.
2016-10-01
Bose-Einstein condensation is a state of matter known to be responsible for peculiar properties exhibited by superfluid Helium-4 and superconductors. Bose-Einstein condensate (BEC) in its pure form is realizable with alkali atoms under ultra-cold temperatures. In this paper, we review the experimental scheme that demonstrates the atomic Bose-Einstein condensate. We also elaborate on the theoretical framework for atomic Bose-Einstein condensation, which includes statistical mechanics and the Gross-Pitaevskii equation. As an extension, we discuss Bose-Einstein condensation of photons realized in a fluorescent dye filled optical microcavity. We analyze this phenomenon based on the generalized Planck's law in statistical mechanics. Further, a comparison is made between photon condensate and laser. We describe how photon condensate may be a possible alternative for lasers since it does not require an energy consuming population inversion process.
Topological objects in two-component Bose-Einstein condensates
Cho, Y. M.; Khim, Hyojoong; Zhang, Pengming
2005-12-15
We study the topological objects in two-component Bose-Einstein condensates. We compare two competing theories of two-component Bose-Einstein condensates, the popular Gross-Pitaevskii theory, and the recently proposed gauge theory of two-component Bose-Einstein condensate which has an induced vorticity interaction. We show that two theories produce very similar topological objects, in spite of the obvious differences in dynamics. Furthermore we show that the gauge theory of two-component Bose-Einstein condensates, with the U(1) gauge symmetry, is remarkably similar to the Skyrme theory. Just like the Skyrme theory this theory admits the non-Abelian vortex, the helical vortex, and the vorticity knot. We construct the lightest knot solution in two-component Bose-Einstein condensates numerically, and discuss how the knot can be constructed in the spin-(1/2) condensate of {sup 87}Rb atoms.
Einstein's First Steps Toward General Relativity: Gedanken Experiments and Axiomatics
NASA Astrophysics Data System (ADS)
Miller, A. I.
1999-03-01
Albert Einstein's 1907 Jahrbuch paper is an extraordinary document because it contains his first steps toward generalizing the 1905 relativity theory to include gravitation. Ignoring the apparent experimental disconfirmation of the 1905 relativity theory and his unsuccessful attempts to generalize the mass-energy equivalence, Einstein boldly raises the mass-energy equivalence to an axiom, invokes equality between gravitational and inertial masses, and then postulates the equivalence between a uniform gravitational field and an oppositely directed constant acceleration, the equivalence principle. How did this come about? What is at issue is scientific creativity. This necessitates broadening historical analysis to include aspects of cognitive science such as the role of visual imagery in Einstein's thinking, and the relation between conscious and unconscious modes of thought in problem solving. This method reveals the catalysts that sparked a Gedanken experiment that occurred to Einstein while working on the Jahrbuch paper. A mental model is presented to further explore Einstein's profound scientific discovery.
A new functional flow equation for Einstein-Cartan quantum gravity
NASA Astrophysics Data System (ADS)
Harst, U.; Reuter, M.
2015-03-01
We construct a special-purpose functional flow equation which facilitates non-perturbative renormalization group (RG) studies on theory spaces involving a large number of independent field components that are prohibitively complicated using standard methods. Its main motivation are quantum gravity theories in which the gravitational degrees of freedom are carried by a complex system of tensor fields, a prime example being Einstein-Cartan theory, possibly coupled to matter. We describe a sequence of approximation steps leading from the functional RG equation of the Effective Average Action to the new flow equation which, as a consequence, is no longer fully exact on the untruncated theory space. However, it is by far more "user friendly" when it comes to projecting the abstract equation on a concrete (truncated) theory space and computing explicit beta-functions. The necessary amount of (tensor) algebra reduces drastically, and the usually very hard problem of diagonalizing the pertinent Hessian operator is sidestepped completely. In this paper we demonstrate the reliability of the simplified equation by applying it to a truncation of the Einstein-Cartan theory space. It is parametrized by a scale dependent Holst action, depending on a O(4) spin-connection and the tetrad as the independent field variables. We compute the resulting RG flow, focusing in particular on the running of the Immirzi parameter, and compare it to the results of an earlier computation where the exact equation had been applied to the same truncation. We find consistency between the two approaches and provide further evidence for the conjectured non-perturbative renormalizability (asymptotic safety) of quantum Einstein-Cartan gravity. We also investigate a duality symmetry relating small and large values of the Immirzi parameter (γ → 1 / γ) which is displayed by the beta-functions in the absence of a cosmological constant.
Cosmography: Cosmology without the Einstein equations
NASA Astrophysics Data System (ADS)
Visser, Matt
2005-09-01
How much of modern cosmology is really cosmography? How much of modern cosmology is independent of the Einstein equations? (Independent of the Friedmann equations?) These questions are becoming increasingly germane—as the models cosmologists use for the stress-energy content of the universe become increasingly baroque, it behaves us to step back a little and carefully disentangle cosmological kinematics from cosmological dynamics. The use of basic symmetry principles (such as the cosmological principle) permits us to do a considerable amount, without ever having to address the vexatious issues of just how much “dark energy”, “dark matter”, “quintessence”, and/or “phantom matter” is needed in order to satisfy the Einstein equations. This is the sub-sector of cosmology that Weinberg refers to as “cosmography”, and in this article I will explore the extent to which cosmography is sufficient for analyzing the Hubble law and so describing many of the features of the universe around us.
Design analysis of the Einstein refrigeration cycle
Shelton, S.V.; Delano, A.; Schaefer, L.A.
1999-07-01
After developing the theory of relativity, Albert Einstein spent several years working with Leo Szilard on absorption refrigeration cycles. In 1930, they obtained a US patent for a unique single pressure absorption cycle. The single pressure eliminates the need for a solution pump. Their cycle has only recently been rediscovered. The cycle utilizes butane as its refrigerant, ammonia as a pressure equalizing fluid, and water as an absorbing fluid. This cycle is dramatically different in both concept and detail than the better-known ammonia-water-hydrogen cycle. In this study, thermodynamic and mixture property models of the Einstein cycle were created to gain insight into the cycle's operating characteristics and to calculate its performance. A conceptual demonstration model was built and successfully operated, showing for the first time the viability of the cycle. The model results found that the system pressure is an important design parameter, with the COP having an optimum when the system pressure is equal to the saturation pressure of the butane refrigerant. It was also found that for a given system pressure, there is a maximum condenser-absorber temperature and a minimum evaporator temperature.
Gravity Before Einstein and Schwinger Before Gravity
NASA Astrophysics Data System (ADS)
Trimble, Virginia L.
2012-05-01
Julian Schwinger was a child prodigy, and Albert Einstein distinctly not; Schwinger had something like 73 graduate students, and Einstein very few. But both thought gravity was important. They were not, of course, the first, nor is the disagreement on how one should think about gravity that is being highlighted here the first such dispute. The talk will explore, first, several of the earlier dichotomies: was gravity capable of action at a distance (Newton), or was a transmitting ether required (many others). Did it act on everything or only on solids (an odd idea of the Herschels that fed into their ideas of solar structure and sunspots)? Did gravitational information require time for its transmission? Is the exponent of r precisely 2, or 2 plus a smidgeon (a suggestion by Simon Newcomb among others)? And so forth. Second, I will try to say something about Scwinger's lesser known early work and how it might have prefigured his "source theory," beginning with "On the Interaction of Several Electrons (the unpublished, 1934 "zeroth paper," whose title somewhat reminds one of "On the Dynamics of an Asteroid," through his days at Berkeley with Oppenheimer, Gerjuoy, and others, to his application of ideas from nuclear physics to radar and of radar engineering techniques to problems in nuclear physics. And folks who think good jobs are difficult to come by now might want to contemplate the couple of years Schwinger spent teaching elementary physics at Purdue before moving on to the MIT Rad Lab for war work.
Interference of Bose-Einstein condensates.
Band, Y B
2008-12-18
A formalism for describing the coherence and interference properties of two atomic clouds of Bose-Einstein condensates (BEC) is presented, which is applicable even in the opposite limits when the BEC clouds are initially coherent and when they are initially independent. First, we develop a mean-field theory wherein one mean-field mode is used, and then, for fragmented (i.e., independent) condensates, we use a mean-field theory with two modes. We then develop a full two-mode field theory, with a field operator composed of a sum of two terms containing matter wave mode functions phi1 and phi2, that multiply the destruction operators of the modes, a1 and a2. When atom-atom interactions are present and when the mode functions overlap, the matter wave mode functions phi1 and phi2 develop components moving to the right and left, and this results in interference fringes in the density. At the many-body level, another source of interference arises from expectation values of the form (a(i)+a(j)) with i double dagger j, which become nonzero due to tunneling and interactions. We detail how these two sources of interference affect the density profile and the density-density correlation functions of Bose-Einstein condensates in the coherent and in the fragmented regimes.
Newton to Einstein — dust to dust
Kopp, Michael; Uhlemann, Cora; Haugg, Thomas E-mail: cora.uhlemann@physik.lmu.de
2014-03-01
We investigate the relation between the standard Newtonian equations for a pressureless fluid (dust) and the Einstein equations in a double expansion in small scales and small metric perturbations. We find that parts of the Einstein equations can be rewritten as a closed system of two coupled differential equations for the scalar and transverse vector metric perturbations in Poisson gauge. It is then shown that this system is equivalent to the Newtonian system of continuity and Euler equations. Brustein and Riotto (2011) conjectured the equivalence of these systems in the special case where vector perturbations were neglected. We show that this approach does not lead to the Euler equation but to a physically different one with large deviations already in the 1-loop power spectrum. We show that it is also possible to consistently set to zero the vector perturbations which strongly constrains the allowed initial conditions, in particular excluding Gaussian ones such that inclusion of vector perturbations is inevitable in the cosmological context. In addition we derive nonlinear equations for the gravitational slip and tensor perturbations, thereby extending Newtonian gravity of a dust fluid to account for nonlinear light propagation effects and dust-induced gravitational waves.
Dirac operators on the Taub-NUT space, monopoles and SU(2) representations
NASA Astrophysics Data System (ADS)
Jante, Rogelio; Schroers, Bernd J.
2014-01-01
We analyse the normalisable zero-modes of the Dirac operator on the TaubNUT manifold coupled to an abelian gauge field with self-dual curvature, and interpret them in terms of the zero modes of the Dirac operator on the 2-sphere coupled to a Dirac monopole. We show that the space of zero modes decomposes into a direct sum of irreducible SU(2) representations of all dimensions up to a bound determined by the spinor charge with respect to the abelian gauge group. Our decomposition provides an interpretation of an index formula due to Pope and provides a possible model for spin in recently proposed geometric models of matter.
NASA Astrophysics Data System (ADS)
Janssen, Michel
2013-12-01
The core of this volume is formed by four chapters (2-5) with detailed reconstructions of the arguments and derivations in four of Einstein's most important papers, the three main papers of his annus mirabilis 1905 (on the light quantum, Brownian motion, and special relativity) and his first systematic exposition of general relativity of 1916. The derivations are given in sufficient detail and in sufficiently modernized notation (without any serious distortion of the originals) for an undergraduate physics major to read and understand them with far less effort than it would take him or her to understand (English translations of) Einstein's original papers. Each of these four papers is accompanied by a detailed introduction, which covers the conceptual development of the relevant field prior to Einstein's contribution to it and corrects some of the myths surrounding these papers that still have not been fully eradicated among physicists. (One quibble: though Kennedy correctly points out that the goal of the light quantum paper was not to explain the photoelectric effect, it is also not quite right to say that 'it was written to explain the Wien region of blackbody radiation' (p. xv). Einstein used this explanatory feat as the central argument for his light quantum hypothesis.) These four chapters then are the most valuable part of the volume. They could be used, independently of one another, but preferably in conjunction with Einstein's original texts, in courses on quantum mechanics, statistical mechanics, electrodynamics, and general relativity, respectively, to add a historical component to such courses. As a historian of science embedded in a physics department who is regularly called upon to give guest lectures in such courses on the history of their subjects, I can highly recommend the volume for this purpose. However, I would not adopt this volume as (one of) the central text(s) for a course on the history of modern physics. For one thing, chapter 1, which in
Energy of Einstein's static universe and its implications for the ΛCDM cosmology
Mitra, Abhas
2013-03-01
The total Einstein energy (P{sub 0}) of a homogeneous and isotropic universe can be computed by using an appropriate superpotential (Rosen 1994) and also by a direct method (Mitra 2010). Irrespective of the physical significance of P{sub 0}, its eventual numerical value must be same in both the cases because both are derived from the same Einstein pseudo tensor and by employing the same coordinates. It follows then that the static isotropic and homogeneous universe, i.e., Einstein's static universe (ESU), must have an infinite radius and which tantamounts to a spatially flat case. The physical significance of this result is that the cosmological constant, Λ, is actually zero and ESU is the vacuous Minkowski spacetime. It is the same result which has recently been obtained in a completely independent manner (Mitra, Bhattacharyya and Bhatt 2013). Thus even though, mathematically, one can conceive of a static 3-sphere for the foundation of relativistic cosmology, physically, no such 3-sphere exists. On the other hand, the spatial section of the universe could essentially be an Euclidean space with local curvature spikes due to presence of lumpy matter. Since the ''Dark Energy'' is associated with Λ in the ΛCDM model, the result obtained here suggests that it is an artifact of departure of the lumpy and fractal universe from the ideal Friedmann Robertson Walker model (Jackson et al. 2012, Cowley et al. 2013)
Einstein's cosmology review of 1933: a new perspective on the Einstein-de Sitter model of the cosmos
NASA Astrophysics Data System (ADS)
O'Raifeartaigh, Cormac; O'Keeffe, Michael; Nahm, Werner; Mitton, Simon
2015-09-01
We present a first English translation and analysis of a little-known review of relativistic cosmology written by Albert Einstein in late 1932. The article, which was published in 1933 in a book of Einstein papers translated into French, contains a substantial review of static and dynamic relativistic models of the cosmos, culminating in a discussion of the Einstein-de Sitter model. The article offers a valuable contemporaneous insight into Einstein's cosmology in the early 1930s and confirms that his interest lay in the development of the simplest model of the cosmos that could account for observation. The article also confirms that Einstein did not believe that simplified relativistic models could give an accurate description of the early universe.
Exploring matter-wave dynamics with a Bose-Einstein condensate
NASA Astrophysics Data System (ADS)
Chang, Rockson
Bose-Einstein condensates of dilute gases provide a rich and versatile platform to study both single-particle and many-body quantum phenomena. This thesis describes several experiments using a Bose-Einstein condensate of Rb-87 as a model system to study novel matter-wave effects that traditionally arise in vastly different systems, yet are difficult to access. We study the scattering of a particle from a repulsive potential barrier in the non-asymptotic regime, for which the collision dynamics are on-going. Using a Bose-Einstein condensate interacting with a sharp repulsive potential, two distinct transient scattering effects are observed: one due to the momentary deceleration of particles atop the barrier, and one due to the abrupt discontinuity in phase written on the wavepacket in position-space, akin to quantum reflection. Both effects lead to a redistribution of momenta, resulting in a rich interference pattern that may be used to reconstruct the single-particle wavefunction. In a second experiment, we study the response of a particle in a periodic potential to an applied force. By abruptly applying an external force to a Bose-Einstein condensate in a one-dimensional optical lattice, we show that the initial response of a particle in a periodic potential is in fact characterized by the bare mass, and only over timescales long compared to that of interband dynamics is the usual effective mass an appropriate description. This breakdown of the effective mass description on fast timescales is difficult to observe in traditional solid state systems due to their large bandgaps and fast timescale of interband dynamics. Both these experiments make use of the condensate's long coherence length, and the ability to shape and modulate the external potential on timescales fast compared to the particle dynamics, allowing for observation of novel matter-wave effects.
NASA Astrophysics Data System (ADS)
Pitts, J. Brian
2016-05-01
Mercury's perihelion right. One can live with absolute rotation but cannot live with instability. Particle physics also can be useful in the historiography of gravity and space-time, both in assessing the growth of objective knowledge and in suggesting novel lines of inquiry to see whether and how Einstein faced the substantially mathematical issues later encountered in particle physics. This topic can be a useful case study in the history of science on recently reconsidered questions of presentism, whiggism and the like. Future work will show how the history of General Relativity, especially Noether's work, sheds light on particle physics.
Affine conformal vectors in space-time
NASA Astrophysics Data System (ADS)
Coley, A. A.; Tupper, B. O. J.
1992-05-01
All space-times admitting a proper affine conformal vector (ACV) are found. By using a theorem of Hall and da Costa, it is shown that such space-times either (i) admit a covariantly constant vector (timelike, spacelike, or null) and the ACV is the sum of a proper affine vector and a conformal Killing vector or (ii) the space-time is 2+2 decomposable, in which case it is shown that no ACV can exist (unless the space-time decomposes further). Furthermore, it is proved that all space-times admitting an ACV and a null covariantly constant vector (which are necessarily generalized pp-wave space-times) must have Ricci tensor of Segré type {2,(1,1)}. It follows that, among space-times admitting proper ACV, the Einstein static universe is the only perfect fluid space-time, there are no non-null Einstein-Maxwell space-times, and only the pp-wave space-times are representative of null Einstein-Maxwell solutions. Otherwise, the space-times can represent anisotropic fluids and viscous heat-conducting fluids, but only with restricted equations of state in each case.
Einstein, race, and the myth of the cultural icon
NASA Astrophysics Data System (ADS)
Jerome, Fred
2004-12-01
The most remarkable aspect of Einstein's 1946 address at Lincoln University is that it has vanished from Einstein's recorded history. Its disappearance into a historical black hole symbolizes what seems to happen in the creation of a cultural icon. It is but one of many political statements by Einstein to have met such a fate, though his civil rights activism is most glaringly mission. One explanation for this historical amnesia is that those who shape our official memories felt that Einstein's "controversial" friends like Paul Robeson and activities like co-chairing the anti-lynching crusade might tarnish Einstein as an icon. That icon, sanctified by Time magazine when it dubbed Einstein "Person of the Century" at the end of 1999, is a myth, albeit a marvelous one. Yet it is not so much the motive for the omission but the consequence of it that should concern us. Americans and the millions of Einstein fans around the world are left unaware that he was an outspoken, passionate, committed antiracist.
Einstein, race, and the myth of the cultural icon.
Jerome, Fred
2004-12-01
The most remarkable aspect of Einstein's 1946 address at Lincoln University is that it has vanished from Einstein's recorded history. Its disappearance into a historical black hole symbolizes what seems to happen in the creation of a cultural icon. It is but one of many political statements by Einstein to have met such a fate, though his civil rights activism is most glaringly missing. One explanation for this historical amnesia is that those who shape our official memories felt that Einstein's "controversial" friends like Paul Robeson and activities like co-chairing the anti-lynching crusade might tarnish Einstein as an icon. That icon, sanctified by Time magazine when it dubbed Einstein "Person of the Century" at the end of 1999, is a myth, albeit a marvelous one. Yet it is not so much the motive for the omission but the consequence of it that should concern us. Americans and the millions of Einstein fans around the world are left unaware that he was an outspoken, passionate, committed antiracist. PMID:16011298
Shock Waves in a Bose-Einstein Condensate
NASA Technical Reports Server (NTRS)
Kulikov, Igor; Zak, Michail
2005-01-01
A paper presents a theoretical study of shock waves in a trapped Bose-Einstein condensate (BEC). The mathematical model of the BEC in this study is a nonlinear Schroedinger equation (NLSE) in which (1) the role of the wave function of a single particle in the traditional Schroedinger equation is played by a space- and time-dependent complex order parameter (x,t) proportional to the square root of the density of atoms and (2) the atoms engage in a repulsive interaction characterized by a potential proportional to | (x,t)|2. Equations that describe macroscopic perturbations of the BEC at zero temperature are derived from the NLSE and simplifying assumptions are made, leading to equations for the propagation of sound waves and the transformation of sound waves into shock waves. Equations for the speeds of shock waves and the relationships between jumps of velocity and density across shock fronts are derived. Similarities and differences between this theory and the classical theory of sound waves and shocks in ordinary gases are noted. The present theory is illustrated by solving the equations for the example of a shock wave propagating in a cigar-shaped BEC.
QUANTUS: Applications of Bose-Einstein condensates in microgravity
NASA Astrophysics Data System (ADS)
Müntinga, Hauke; van Zoest, T.; Ahlers, H.; Seidel, S. T.; Herr, W.; Rudolph, J.; Gaaloul, N.; Singh, Y.; Schulze, T. A.; Rode, C.; Schkolnik, V.; Ertmer, W.; Rasel, E.; Müntinga, H.; Künemann, T.; Resch, A.; Herrmann, S.; Lümmerzahl, C.; Dittus, H.; Vogel, A.; Wenzlawski, A.; Sengstock, K.; Meyer, N.; Bongs, K.; Krutzik, M.; Lewoczko-Adamczyk, W.; Schiemangk, M.; Peters, A.; Eckart, M.; Kajari, E.; Arnold, S.; Nandi, G.; Walser, R.; Schleich, W. P.; Steinmetz, T.; Hünsch, T. W.; Reichel, J.
We report on the current status of the QUANTUS free fall BEC experiment at the ZARM drop tower in Bremen. After the first realization of a BEC in microgravity in 2007, we were able to observe conden-sates after an unprecedented time of free evolution. The extremely shallow traps possible in microgravity and resulting ultralow temperatures of a few nK allow for further studies ranging from coherence properties of condensates to inertial sensors based on matter waves. In our talk we will focus on the implementation of a matter wave interferometer into our appa-ratus, which aims to extend measurements to unprecedented interrogation times and sensitivi-ties. This leads the way to high precision measurements of gravitational forces and eventually a quantum test of Einstein's weak equivalence principle. Phenomena like decoherence, quantum reflection and Anderson localization can also be examined with our apparatus. These goals are worked on in close cooperation with QUEST and the projects PRIMUS and LASUS. The QUANTUS project is a collaboration of U Hamburg, U Ulm, HU Berlin, MPQ Munich, ZARM at U Bremen and LU Hannover. It is supported by the German Space Agency DLR with funds provided by the Federal Ministry of Economics and Technology (BMWi) under grant numbers 50WM0835 -50WM0839.
Satisfying the Einstein-Podolsky-Rosen criterion with massive particles.
Peise, J; Kruse, I; Lange, K; Lücke, B; Pezzè, L; Arlt, J; Ertmer, W; Hammerer, K; Santos, L; Smerzi, A; Klempt, C
2015-11-27
In 1935, Einstein, Podolsky and Rosen (EPR) questioned the completeness of quantum mechanics by devising a quantum state of two massive particles with maximally correlated space and momentum coordinates. The EPR criterion qualifies such continuous-variable entangled states, where a measurement of one subsystem seemingly allows for a prediction of the second subsystem beyond the Heisenberg uncertainty relation. Up to now, continuous-variable EPR correlations have only been created with photons, while the demonstration of such strongly correlated states with massive particles is still outstanding. Here we report on the creation of an EPR-correlated two-mode squeezed state in an ultracold atomic ensemble. The state shows an EPR entanglement parameter of 0.18(3), which is 2.4 s.d. below the threshold 1/4 of the EPR criterion. We also present a full tomographic reconstruction of the underlying many-particle quantum state. The state presents a resource for tests of quantum nonlocality and a wide variety of applications in the field of continuous-variable quantum information and metrology.
Reconsidering a Scientific Revolution: The Case of Einstein versus Lorentz
NASA Astrophysics Data System (ADS)
Janssen, Michel
The relationship between Albert Einstein's special theory of relativity and Hendrik A. Lorentz's ether theory is best understood in terms of competing interpretations of Lorentz invariance. In the 1890s, Lorentz proved and exploited the Lorentz invariance of Maxwell's equations, the laws governing electromagnetic fields in the ether, with what he called the theorem of corresponding states. To account for the negative results of attempts to detect the earth's motion through the ether, Lorentz, in effect, had to assume that the laws governing the matter interacting with the fields are Lorentz invariant as well. This additional assumption can be seen as a generalization of the well-known contraction hypothesis. In Lorentz's theory, it remained an unexplained coincidence that both the laws governing fields and the laws governing matter should be Lorentz invariant. In special relativity, by contrast, the Lorentz invariance of all physical laws directly reflects the Minkowski space-time structure posited by the theory. One can use this observation to produce a common-cause argument to show that the relativistic interpretation of Lorentz invariance is preferable to Lorentz's interpretation.
Dynamical black holes with symmetry in Einstein Gauss Bonnet gravity
NASA Astrophysics Data System (ADS)
Nozawa, Masato; Maeda, Hideki
2008-03-01
We explore various aspects of dynamical black holes defined by a future outer trapping horizon in n(>=5)-dimensional Einstein Gauss Bonnet gravity. In the present paper, we assume that the spacetime has symmetries corresponding to the isometries of an (n - 2)-dimensional maximally symmetric space and the Gauss Bonnet coupling constant is non-negative. Depending on the existence or absence of the general relativistic limit, solutions are classified into GR and non-GR branches, respectively. Assuming the null energy condition on matter fields, we show that a future outer trapping horizon in the GR branch possesses the same properties as that in general relativity. In contrast, that in the non-GR branch is shown to be non-spacelike with its area non-increasing into the future. We can recognize that this peculiar behavior arises from the fact that the null energy condition necessarily leads to the null convergence condition for radial null vectors in the GR branch, but not in the non-GR branch. The energy balance law yields the first law of a trapping horizon, from which we can read off the entropy of a trapping horizon reproducing Iyer Wald's expression. The entropy of a future outer trapping horizon is shown to be non-decreasing in both branches along its generator.
Formation and decay of Einstein-Yang-Mills black holes
NASA Astrophysics Data System (ADS)
Rinne, Oliver
2014-12-01
We study various aspects of black holes and gravitational collapse in Einstein-Yang-Mills theory under the assumption of spherical symmetry. Numerical evolution on hyperboloidal surfaces extending to future null infinity is used. We begin by constructing colored and Reissner-Nordström black holes on surfaces of constant mean curvature and analyze their perturbations. These linearly perturbed black holes are then evolved into the nonlinear regime and the masses of the final Schwarzschild black holes are computed as a function of the initial horizon radius. We compare with an information-theoretic bound on the lifetime of unstable hairy black holes derived by Hod. Finally we study critical phenomena in gravitational collapse at the threshold between different Yang-Mills vacuum states of the final Schwarzschild black holes, where the n =1 colored black hole forms the critical solution. The work of Choptuik et al. [Phys. Rev. D 60, 124011 (1999)] is extended by using a family of initial data that includes another region in parameter space where the colored black hole with the opposite sign of the Yang-Mills potential forms the critical solution. We investigate the boundary between the two regions and discover that the Reissner-Nordström solution appears as a new approximate codimension-two attractor.
Einstein gravity as a 3D conformally invariant theory
NASA Astrophysics Data System (ADS)
Gomes, Henrique; Gryb, Sean; Koslowski, Tim
2011-02-01
We give an alternative description of the physical content of general relativity that does not require a Lorentz invariant spacetime. Instead, we find that gravity admits a dual description in terms of a theory where local size is irrelevant. The dual theory is invariant under foliation-preserving 3-diffeomorphisms and 3D conformal transformations that preserve the 3-volume (for the spatially compact case). Locally, this symmetry is identical to that of Hořava-Lifshitz gravity in the high energy limit but our theory is equivalent to Einstein gravity. Specifically, we find that the solutions of general relativity, in a gauge where the spatial hypersurfaces have constant mean extrinsic curvature, can be mapped to solutions of a particular gauge fixing of the dual theory. Moreover, this duality is not accidental. We provide a general geometric picture for our procedure that allows us to trade foliation invariance for conformal invariance. The dual theory provides a new proposal for the theory space of quantum gravity.
What about Albert Einstein? Using Biographies to Promote Students' Scientific Thinking
ERIC Educational Resources Information Center
Fingon, Joan C.; Fingon, Shallon D.
2009-01-01
Who hasn't heard of Einstein? Science educators everywhere are familiar with Einstein's genius and general theory of relativity. Students easily recognize Einstein's image by his white flyaway hair and bushy mustache. It is well known that Einstein was a brilliant physicist and an abstract thinker who often used his creativity and imagination in…
Finsler geometric extension of Einstein gravity
NASA Astrophysics Data System (ADS)
Pfeifer, Christian; Wohlfarth, Mattias N. R.
2012-03-01
We construct gravitational dynamics for Finsler spacetimes in terms of an action integral on the unit tangent bundle. These spacetimes are generalizations of Lorentzian metric manifolds which satisfy necessary causality properties. A coupling procedure for matter fields to Finsler gravity completes our new theory that consistently becomes equivalent to Einstein gravity in the limit of metric geometry. We provide a precise geometric definition of observers and their measurements and show that the transformations, by means of which different observers communicate, form a groupoid that generalizes the usual Lorentz group. Moreover, we discuss the implementation of Finsler spacetime symmetries. We use our results to analyze a particular spacetime model that leads to Finsler geometric refinements of the linearized Schwarzschild solution.
The Dark Universe Through Einstein's Lens
Bard, Deborah
2013-07-23
Bard's talk explains the phenomenon known as gravitational lensing and how astrophysicists use it to explore the 95 percent of the universe that remains unseen: dark matter and dark energy. One of the most surprising predictions made by Einstein's theory of relativity is that light doesn't travel through the universe in a straight line. The gravitational field of massive objects will deflect the path of light traveling past, giving some very dramatic effects. We see multiple images of quasars, galaxies smeared into arcs and circles and magnified images of the most distant objects in the universe. This explains how gravitational lensing was first observed and discusses how scientists use this phenomenon to study everything from exoplanets to dark matter to the structure of the universe and the mysterious dark energy.
An Introduction to the Einstein Toolkit
NASA Astrophysics Data System (ADS)
Zilhão, Miguel; Löffler, Frank
2013-09-01
We give an introduction to the Einstein Toolkit, a mature, open-source computational infrastructure for numerical relativity based on the Cactus Framework, for the target group of new users. This toolkit is composed of several different modules, is developed by researchers from different institutions throughout the world and is in active continuous development. Documentation for the toolkit and its several modules is often scattered across different locations, a difficulty new users may at times have to struggle with. Scientific papers exist describing the toolkit and its methods in detail, but they might be overwhelming at first. With these lecture notes we hope to provide an initial overview for new users. We cover how to obtain, compile and run the toolkit, and give an overview of some of the tools and modules provided with it.
Einstein observations of the galactic centre
NASA Technical Reports Server (NTRS)
Watson, M. G.; Willingale, R.; Hertz, P.; Grindlay, J. E.
1981-01-01
A description is presented of the X-ray observations made with the Einstein Observatory Imaging Proportional Counter of a 1 x 1 degree field centered near the galactic nucleus. In the direction of the galactic center the interstellar medium is generally opaque to all radiation between the visual and extreme ultraviolet due to the large column density of the intervening gas and dust. The importance of this X-ray study lies in the fact that it opens up a new window in which the central regions of the Milky Way Galaxy can be observed. The X-ray image is clearly dominated by a bright, central region of emission elongated along the galactic plane. Also presented are a number of unresolved sources.
Groups, information theory, and Einstein's likelihood principle
NASA Astrophysics Data System (ADS)
Sicuro, Gabriele; Tempesta, Piergiulio
2016-04-01
We propose a unifying picture where the notion of generalized entropy is related to information theory by means of a group-theoretical approach. The group structure comes from the requirement that an entropy be well defined with respect to the composition of independent systems, in the context of a recently proposed generalization of the Shannon-Khinchin axioms. We associate to each member of a large class of entropies a generalized information measure, satisfying the additivity property on a set of independent systems as a consequence of the underlying group law. At the same time, we also show that Einstein's likelihood function naturally emerges as a byproduct of our informational interpretation of (generally nonadditive) entropies. These results confirm the adequacy of composable entropies both in physical and social science contexts.
A repulsive force in the Einstein theory
NASA Astrophysics Data System (ADS)
Gorkavyi, Nick; Vasilkov, Alexander
2016-09-01
The Laser Interferometer Gravitational-Wave Observatory (LIGO) detection of gravitational waves that take away 5 per cent of the total mass of two merging black holes points out on the importance of considering varying gravitational mass of a system in the framework of the Einstein general theory of relativity. We calculate the acceleration of a particle in the non-stationary field of a quasi-spherical system composed of a large number of objects emitting gravitational waves. It is shown that reduction of the gravitational mass of the system due to emitting gravitational waves leads to a repulsive gravitational force that diminishes with time but never disappears. This repulsive force may be related to the observed expansion of the Universe.
Groups, information theory, and Einstein's likelihood principle.
Sicuro, Gabriele; Tempesta, Piergiulio
2016-04-01
We propose a unifying picture where the notion of generalized entropy is related to information theory by means of a group-theoretical approach. The group structure comes from the requirement that an entropy be well defined with respect to the composition of independent systems, in the context of a recently proposed generalization of the Shannon-Khinchin axioms. We associate to each member of a large class of entropies a generalized information measure, satisfying the additivity property on a set of independent systems as a consequence of the underlying group law. At the same time, we also show that Einstein's likelihood function naturally emerges as a byproduct of our informational interpretation of (generally nonadditive) entropies. These results confirm the adequacy of composable entropies both in physical and social science contexts.
Nonlinear interferometry with Bose-Einstein condensates
Tacla, Alexandre B.; Boixo, Sergio; Datta, Animesh; Shaji, Anil; Caves, Carlton M.
2010-11-15
We analyze a proposed experiment [Boixo et al., Phys. Rev. Lett. 101, 040403 (2008)] for achieving sensitivity scaling better than 1/N in a nonlinear Ramsey interferometer that uses a two-mode Bose-Einstein condensate (BEC) of N atoms. We present numerical simulations that confirm the analytical predictions for the effect of the spreading of the BEC ground-state wave function on the ideal 1/N{sup 3/2} scaling. Numerical integration of the coupled, time-dependent, two-mode Gross-Pitaevskii equations allows us to study the several simplifying assumptions made in the initial analytic study of the proposal and to explore when they can be justified. In particular, we find that the two modes share the same spatial wave function for a length of time that is sufficient to run the metrology scheme.
Groups, information theory, and Einstein's likelihood principle.
Sicuro, Gabriele; Tempesta, Piergiulio
2016-04-01
We propose a unifying picture where the notion of generalized entropy is related to information theory by means of a group-theoretical approach. The group structure comes from the requirement that an entropy be well defined with respect to the composition of independent systems, in the context of a recently proposed generalization of the Shannon-Khinchin axioms. We associate to each member of a large class of entropies a generalized information measure, satisfying the additivity property on a set of independent systems as a consequence of the underlying group law. At the same time, we also show that Einstein's likelihood function naturally emerges as a byproduct of our informational interpretation of (generally nonadditive) entropies. These results confirm the adequacy of composable entropies both in physical and social science contexts. PMID:27176234
NASA Astrophysics Data System (ADS)
Ayissi, Raoul Domingo; Noutchegueme, Norbert
2015-01-01
global in time existence and uniqueness of a regular solution to the Einstein-Maxwell-Boltzmann system with the cosmological constant. We define and we use the weighted Sobolev separable spaces for the Boltzmann equation; some special spaces for the Einstein equations, then we clearly display all the proofs leading to the global existence theorems.
Ayissi, Raoul Domingo Noutchegueme, Norbert
2015-01-15
global in time existence and uniqueness of a regular solution to the Einstein-Maxwell-Boltzmann system with the cosmological constant. We define and we use the weighted Sobolev separable spaces for the Boltzmann equation; some special spaces for the Einstein equations, then we clearly display all the proofs leading to the global existence theorems.
Chaotic Josephson effects in two-coupled Bose-Einstein condensates
NASA Astrophysics Data System (ADS)
Fang, Jianshu; Hai, Wenhua; Chong, Guishu; Xie, Qiongtao
2005-04-01
We discuss the chaotic Josephson effects in two weakly coupled Bose-Einstein condensates (BECs). The boson Josephson junction (BJJ) dynamics in BECs is governed by the two-mode Gross-Pitaevskii equation. We obtained a perturbed chaotic solution of the BJJ equation by using the direct perturbation technique. Theoretical analysis reveals that the stable oscillating orbits are embedded in the Melnikov chaotic attractors. The corresponding numerical results show that the Poincaré sections in the equivalent phase space (φ,φ˙) sensitively depends on the system parameter and initial conditions. Therefore, we can control the transitions between chaos and order by adjusting these parameters and conditions.
Anderson Localization of a Bose-Einstein Condensate in a 3D Random Potential
Skipetrov, S. E.; Minguzzi, A.; Tiggelen, B. A. van; Shapiro, B.
2008-04-25
We study the effect of Anderson localization on the expansion of a Bose-Einstein condensate, released from a harmonic trap, in a 3D random potential. We use scaling arguments and the self-consistent theory of localization to show that the long-time behavior of the condensate density is controlled by a single parameter equal to the ratio of the mobility edge and the chemical potential of the condensate. We find that the two critical exponents of the localization transition determine the evolution of the condensate density in time and space.
Chaos enhancing tunneling in a coupled Bose-Einstein condensate with a double driving.
Rong, Shiguang; Hai, Wenhua; Xie, Qiongtao; Zhu, Qianquan
2009-09-01
We study the effects of chaotic dynamics on atomic tunneling between two weakly coupled Bose-Einstein condensates driven by a double-frequency periodic field. Under the Melnikov's chaos criterion, we divide the parameter space into three parts of different types, regular region, low-chaoticity region, and high-chaoticity region, and give the accurate boundaries between the different regions. It is found that the atomic tunneling can be enhanced in the presence of chaos. Particularly, in the high-chaoticity regions, the chaos-induced inversion of the population imbalance is observed numerically. PMID:19792009
Measuring two-particle Bose-Einstein correlations with PHOBOS@RHIC
Betts, R.; Barton, D.; Carroll, A.
1995-07-15
The authors present results of a simulation of the measurement of two-particle Bose-Einstein correlations in central Au-Au collisions with the PHOBOS detector at RHIC. This measurement is expected to yield information on the relevant time and distance scales in these collisions. As the space-time scale is directly connected with the equation of state governing the evolution of the particle source, this information will be essential in understanding the physics of nucleus-nucleus collisions at RHIC energies. The authors demonstrate that the PHOBOS detector has sufficient resolution and acceptance to distinguish a variety of physics scenarios.
Qualitative analysis of a generalized Maxwell-Einstein system - Application for a cosmological model
NASA Astrophysics Data System (ADS)
Tossa, Joel; Fabris, Julo C.; Romero, Carlos
1992-02-01
A methodology for studying dynamical systems is employed to qualitatively analyze the relationship between a Maxwellian field coupled to gravity and Einstein equations. The Maxwellian-type field is assumed to have n even dimensions to develop variables describing the expansion factor of the 4D universe and the variation of the gravitational constant. The resulting phase diagram is analyzed and found to have trajectories expanding from a singularity at infinity and tending toward equilibrium. This description of Minkowskian space-time is complemented by nonphysical regions in which trajectories originating from a 'big-bang' singularity tend toward an unstable singularity at infinity.
Measuring two-particle Bose-Einstein correlations with PHOBOS@RHIC
Betts, R.; Barton, D.; Carroll, A.
1995-12-31
We present results of a simulation of the measurement of two-particle Bose-Einstein correlations in central Au-Au collisions with the PHOBOS detector at RHIC. This measurement is expected to yield information on the relevant time and distance scales in these collisions. As the space-time scale is directly connected with the equation of state governing the evolution of the particle source, this information will be essential in understanding the physics of nucleus-nucleus collisions at RHIC energies. We demonstrate that the PHOBOS detector has sufficient resolution and acceptance to distinguish a variety of physics scenarios.
Some exact solutions with torsion in 5D Einstein-Gauss-Bonnet gravity
Canfora, F.; Giacomini, A.; Willison, S.
2007-08-15
Exact solutions with torsion in Einstein-Gauss-Bonnet gravity are derived. These solutions have a cross product structure of two constant curvature manifolds. The equations of motion give a relation for the coupling constants of the theory in order to have solutions with nontrivial torsion. This relation is not the Chern-Simons combination. One of the solutions has an AdS{sub 2}xS{sup 3} structure and is so the purely gravitational analogue of the Bertotti-Robinson space-time where the torsion can be seen as the dual of the covariantly constant electromagnetic field.
Derivation of Einstein-Cartan theory from general relativity
NASA Astrophysics Data System (ADS)
Petti, Richard
2016-03-01
This article presents a derivation of Einstein-Cartan theory from general relativity with no additional assumptions or parameters. The derivation begins with distributions of Kerr masses that converge to a continuum with constant densities of mass, momentum, and angular momentum. The limit includes torsion and the spin-torsion relationship of Einstein-Cartan theory. The construction of curvature and torsion is equivalent to definition of curvature with Cartan forms on fiber bundles. Advantages of Einstein-Cartan theory include accommodating exchange of classical intrinsic and orbital angular momentum and generation of inflation-like expansion in high density cosmological models.
Vector azimuthons in two-component Bose-Einstein condensates
Lashkin, Volodymyr M.; Ostrovskaya, Elena A.; Desyatnikov, Anton S.; Kivshar, Yuri S.
2009-07-15
We introduce matter-wave vector azimuthons, i.e., spatially localized vortex states with azimuthal modulations of density, in multicomponent Bose-Einstein condensates. These localized states generalize spatially modulated vortex solitons introduced earlier in nonlinear optics [A. S. Desyatnikov, A. A. Sukhorukov, and Yu. S. Kivshar, Phys. Rev. Lett. 95, 203904 (2005)] and Bose-Einstein condensates [V. M. Lashkin, Phys. Rev. A 77, 025602 (2008)]. We find, numerically, nonrotating and rotating two-component azimuthons in a Bose-Einstein condensate with a negative scattering length confined by a quasi-two-dimensional parabolic trap.
Generating exact solutions to Einstein's equation using linearized approximations
NASA Astrophysics Data System (ADS)
Harte, Abraham I.; Vines, Justin
2016-10-01
We show that certain solutions to the linearized Einstein equation can—by the application of a particular type of linearized gauge transformation—be straightforwardly transformed into solutions of the exact Einstein equation. In cases with nontrivial matter content, the exact stress-energy tensor of the transformed metric has the same eigenvalues and eigenvectors as the linearized stress-energy tensor of the initial approximation. When our gauge exists, the tensorial structure of transformed metric perturbations identically eliminates all nonlinearities in Einstein's equation. As examples, we derive the exact Kerr and gravitational plane wave metrics from standard harmonic-gauge approximations.
Einstein, Perrin, and the reality of atoms: 1905 revisited
NASA Astrophysics Data System (ADS)
Newburgh, Ronald; Peidle, Joseph; Rueckner, Wolfgang
2006-06-01
We have repeated Perrin's 1908 experiment for the determination of Avogadro's number by determining the mean square displacement of small particles undergoing Brownian motion. Our apparatus differs from Perrin's by the use of a CCD camera and is much less tedious to perform. We review Einstein's 1905 analysis of Brownian motion and Langevin's alternative derivation of the Einstein equation for the mean square displacement. We also show how Einstein's thinking was a reflection of his belief in the validity of molecular-kinetic theory, a validity not universally recognized 100 years ago.
Einsteins Spuren in den Archiven der Wissenschaft: Physikgeschichte
NASA Astrophysics Data System (ADS)
Marx, Werner
2005-07-01
Die Erwähnungen und Zitierungen von Einsteins Arbeiten dokumentieren lediglich den quantifizierbaren Anteil von Einsteins Beitrag zur Physik. Gleichwohl belegen sie die außergewöhnliche Resonanz und Langzeitwirkung seiner Arbeiten. Die Häufigkeit der Zitierungen entspricht nicht der allgemeinen Einschätzung ihrer Bedeutung. Insbesondere die Pionierarbeiten werden inzwischen als bekannt vorausgesetzt und nicht mehr explizit zitiert. Interessanterweise ist seine nach 1945 meist zitierte Arbeit nicht eine der Pionierarbeiten zur Quantenphysik oder Relativitätstheorie, sondern jene aus dem Jahr 1935 zum berühmten Einstein-Podolsky-Rosen-Paradoxon.
Is Karl Landsteiner the Einstein of the biomedical sciences?
Kantha, S S
1995-04-01
If Albert Einstein is the acclaimed peerless genius among the physical scientists of this century, who can claim the equivalent title among the biomedical scientists? The research contributions of 24 Nobelists in medicine (contemporaries of Einstein) who received the Nobel prize between 1912 and 1966 were analyzed. When assessed on three criteria, (a) influence in multiple disciplines, (b) revolutionary in opening new vistas of knowledge, and (c) significant impact to human life, Karl Landsteiner's discoveries of the human blood groups stand out prominently. Thus, Landsteiner seems an appropriate choice to use as a 'control' to analyze Einstein's productivity.
Einstein's Approach to Statistical Mechanics: The 1902-04 Papers
NASA Astrophysics Data System (ADS)
Peliti, Luca; Rechtman, Raúl
2016-09-01
We summarize the papers published by Einstein in the Annalen der Physik in the years 1902-1904 on the derivation of the properties of thermal equilibrium on the basis of the mechanical equations of motion and of the calculus of probabilities. We point out the line of thought that led Einstein to an especially economical foundation of the discipline, and to focus on fluctuations of the energy as a possible tool for establishing the validity of this foundation. We also sketch a comparison of Einstein's approach with that of Gibbs, suggesting that although they obtained similar results, they had different motivations and interpreted them in very different ways.
Why Einstein did not believe that general relativity geometrizes gravity
NASA Astrophysics Data System (ADS)
Lehmkuhl, Dennis
2014-05-01
I argue that, contrary to folklore, Einstein never really cared for geometrizing the gravitational or (subsequently) the electromagnetic field; indeed, he thought that the very statement that General Relativity geometrizes gravity "is not saying anything at all". Instead, I shall show that Einstein saw the "unification" of inertia and gravity as one of the major achievements of General Relativity. Interestingly, Einstein did not locate this unification in the field equations but in his interpretation of the geodesic equation, the law of motion of test particles.
EDITORIAL: Squeeze transformation and optics after Einstein
NASA Astrophysics Data System (ADS)
Kim, Young S.; Man'ko, Margarita A.; Planat, Michel
2005-12-01
With this special issue, Journal of Optics B: Quantum and Semiclassical Optics contributes to the celebration of the World Year of Physics held in recognition of five brilliant papers written by Albert Einstein in 1905. There is no need to explain to the readers of this journal the content and importance of these papers, which are cornerstones of modern physics. The 51 contributions in this special issue represent current trends in quantum optics —100 years after the concept of light quanta was introduced. At first glance, in his famous papers of 1905, Einstein treated quite independent subjects—special relativity, the nature and statistical properties of light, electrodynamics of moving bodies and Brownian motion. We now know that all these phenomena are deeply related, and these relations are clearly shown in many papers in this issue. Most of the papers are based on the talks and poster contributions from participants of the 9th International Conference on Squeezed States and Uncertainty Relations (ICSSUR'05), which took place in Besançon, France, 2-6 May, 2005. This was the continuation of a series of meetings, originating with the first workshops organized by Professor Y S Kim at the University of Maryland, College Park, USA, in 1991 and by Professor V I Man'ko at the Lebedev Physical Institute, Moscow in 1992. One of the main topics of ICSSUR'05 and this special issue is the theory and applications of squeezed states and their generalizations. At first glance, one could think that this subject has no relation to Einstein's papers. However, this is not true: the theory of squeezed states is deeply related to special relativity, as far as it is based on the representations of the Lorentz group (see the paper by Kim Y S and Noz M E, S458-S467), which also links the current concepts of entanglement and decoherence with Lorentz-covariance. Besides, studies of the different quantum states of light imply, after all, the study of photon (or photo
Revisiting Einstein's Happiest Thought: On Ernst Mach and the Early History of Relativity
NASA Astrophysics Data System (ADS)
Staley, Richard
2016-03-01
This paper argues we should distinguish three phases in the formation of relativity. The first involved relational approaches to perception, and physiological and geometrical space and time in the 1860s and 70s. The second concerned electrodynamics and mechanics (special relativity). The third concerned mechanics, gravitation, and physical and geometrical space and time. Mach's early work on the Doppler effect, together with studies of visual and motor perception linked physiology, physics and psychology, and offered new approaches to physiological space and time. These informed the critical conceptual attacks on Newtonian absolutes that Mach famously outlined in The Science of Mechanics. Subsequently Mach identified a growing group of ``relativists,'' and his critiques helped form a foundation for later work in electrodynamics (in which he did not participate). Revisiting Mach's early work will suggest he was still more important to the development of new approaches to inertia and gravitation than has been commonly appreciated. In addition to what Einstein later called ``Mach's principle,'' I will argue that a thought experiment on falling bodies in Mach's Science of Mechanics also provided a point of inspiration for the happy thought that led Einstein to the equivalence principle.
Unique Stellar System Gives Einstein a Thumbs-Up
NASA Astrophysics Data System (ADS)
2008-07-01
down the geometry of the double-pulsar system and track changes in the orientation of the spin axis of one of them. As one pulsar's spin axis slowly moved, the pattern of signal blockages as the other passed behind it also changed. The signal from the pulsar in back is absorbed by the ionized gas in the other's magnetosphere. Pulsars, first discovered in 1967, are the "corpses" of massive stars that have exploded as supernovae. What is left after the explosion is a superdense neutron star that packs more than the mass of our Sun into the size of an average city. Beams of radio waves stream outward from the poles of the star's intense magnetic field and sweep around as the star rotates, as often as hundreds of times a second. The pair of pulsars studied with the GBT is about 1700 light-years from Earth. The average distance between the two is only about twice the distance from the Earth to the Moon. The two orbit each other in just under two and a half hours. "A system like this, with two very massive objects very close to each other, is precisely the kind of extreme 'cosmic laboratory' needed to test Einstein's prediction," said Victoria Kaspi, leader of McGill University's Pulsar Group. Theories of gravity don't differ significantly in "ordinary" regions of space such as our own Solar System. In regions of extremely strong gravity fields, such as near a pair of close, massive objects, however, differences are expected to show up. In the binary-pulsar study, General Relativity "passed the test" provided by such an extreme environment, the scientists said. "It's not quite right to say that we have now 'proven' General Relativity," Breton said. "However, so far, Einstein's theory has passed all the tests that have been conducted, including ours." Breton, Kaspi and Ransom worked with Michael Kramer of the Jodrell Bank Observatory at the University of Manchester in Great Britain; Maura McLaughlin of West Virginia University and the NRAO; Maxim Lyutikov of Purdue University
NASA Astrophysics Data System (ADS)
Janssen, Michel
2013-12-01
The core of this volume is formed by four chapters (2-5) with detailed reconstructions of the arguments and derivations in four of Einstein's most important papers, the three main papers of his annus mirabilis 1905 (on the light quantum, Brownian motion, and special relativity) and his first systematic exposition of general relativity of 1916. The derivations are given in sufficient detail and in sufficiently modernized notation (without any serious distortion of the originals) for an undergraduate physics major to read and understand them with far less effort than it would take him or her to understand (English translations of) Einstein's original papers. Each of these four papers is accompanied by a detailed introduction, which covers the conceptual development of the relevant field prior to Einstein's contribution to it and corrects some of the myths surrounding these papers that still have not been fully eradicated among physicists. (One quibble: though Kennedy correctly points out that the goal of the light quantum paper was not to explain the photoelectric effect, it is also not quite right to say that 'it was written to explain the Wien region of blackbody radiation' (p. xv). Einstein used this explanatory feat as the central argument for his light quantum hypothesis.) These four chapters then are the most valuable part of the volume. They could be used, independently of one another, but preferably in conjunction with Einstein's original texts, in courses on quantum mechanics, statistical mechanics, electrodynamics, and general relativity, respectively, to add a historical component to such courses. As a historian of science embedded in a physics department who is regularly called upon to give guest lectures in such courses on the history of their subjects, I can highly recommend the volume for this purpose. However, I would not adopt this volume as (one of) the central text(s) for a course on the history of modern physics. For one thing, chapter 1, which in
Sommerfeld's influence on Einstein's evaluation of Minkowski, 1908 to 1916
NASA Astrophysics Data System (ADS)
Smith, Felix T.
2016-03-01
Einstein (E.), who had begun entirely hostile to Minkowski's (M.'s) space-time view of relativity in 1908, completely reversed himself by March 1916, saying in the second sentence of his major article on General Relativity (G.R.) in Ann. d. Phys.: ``The generalization of the theory of relativity was greatly facilitated through the form that the special theory of relativity was given by Minkowski, the mathematician who first made clear the formal equivalence of the spatial coordinates and the time coordinate and made it practically useable for the construction of the theory.'' Two major steps in this evolution exhibit E.'s respect for Sommerfeld's (S.'s) knowledge and judgment. At a meeting in Salzburg, Sept., 1909, they discussed and disagreed strongly about the value of M.'s contributions, but by the Feb., 1910, Part 2 of a survey paper E. had come to follow S. in accepting fully M.'s space-time and its coordinate x4 = ict . Step 2 followed S.'s June, 1915, publication of a 1907 lecture on relativity by M., doctoring it slightly to influence E. Unknown is whatever else S. communicated to E. at that time, but S.'s unrivalled knowledge of the implications of M.'s 4-vector algebra and analysis were at E.'s disposal. There soon followed both a paper by E. in Feb., 1916, adapting to the needs of G.R. a covariant form of Maxwell's equations discovered by M., and then E.'s handsome acknowledgement in March. The importance of early personality issues between M. and E. and of S.'s later diplomatic interventions will be explored.
Cylindrically symmetric Einstein-Yang-Mills-Higgs gauge configurations.
NASA Astrophysics Data System (ADS)
Mondaini, R. P.
1985-02-01
Two solutions are obtained for coupled Einstein-Yang-Mills-Higgs fields with cylindrical symmetry and rigid rotation. The Higgs fields are responsible for the creation of singularities and infinite energy densities at the cylinder's axis.
Bose-Einstein condensation of dilute atomic gases
NASA Astrophysics Data System (ADS)
Wu, Biao
The Bose-Einstein condensation of dilute atomic gases is studied. The focus is on the interesting properties and the dynamical behavior of Bose-Einstein condensates (BECs1) under various external manipulations. We investigate how the interaction affects the interference pattern between two BEC clouds, and show how the interference pattern can be calculated. We then present a theory on the generation of dark solitons in BECs with a new experimental technique called phase imprint. By mapping this problem into a classic pendulum problem, we show how to design the phase step imprinted on a BEC cloud to generate desired dark solitons. We finally study the system of a BEC in an optical lattice, a nonlinear periodic system, which exhibits interesting new effects on the tunneling and superfluidity in terms of its Bloch bands and Bloch waves. 1In the dissertation, BEC stands for Bose-Einstein condensate, not Bose-Einstein condensation.
From the Einstein-Szilard Patent to Modern Magnetohydrodynamics.
ERIC Educational Resources Information Center
Povh, I. L.; Barinberg, A. D.
1979-01-01
Examines present-day and future prospects of the applications of modern magnetohydrodynamics in a number of countries. Explains how the electromagnetic pump, which was invented by Einstein and Leo Szilard, led to the development of applied magnetohydrodynamics. (HM)
Induced matter brane gravity and Einstein static universe
Heydarzade, Y.; Darabi, F. E-mail: f.darabi@azaruniv.edu
2015-04-01
We investigate stability of the Einstein static universe against the scalar, vector and tensor perturbations in the context of induced matter brane gravity. It is shown that in the framework of this model, the Einstein static universe has a positive spatial curvature. In contrast to the classical general relativity, it is found that a stable Einstein static universe against the scalar perturbations does exist provided that the variation of time dependent geometrical equation of state parameter is proportional to the minus of the variation of the scale factor, δ ω{sub g}(t) = −Cδ a(t). We obtain neutral stability against the vector perturbations, and the stability against the tensor perturbations is guaranteed due to the positivity of the spatial curvature of the Einstein static universe in induced matter brane gravity.
Einstein's conversion from his static to an expanding universe
NASA Astrophysics Data System (ADS)
Nussbaumer, Harry
2014-02-01
In 1917 Einstein initiated modern cosmology by postulating, based on general relativity, a homogenous, static, spatially curved universe. To counteract gravitational contraction he introduced the cosmological constant. In 1922 Alexander Friedman showed that Albert Einstein's fundamental equations also allow dynamical worlds, and in 1927 Georges Lemaître, backed by observational evidence, concluded that our universe was expanding. Einstein impetuously rejected Friedman's as well as Lemaître's findings. However, in 1931 he retracted his former static model in favour of a dynamic solution. This investigation follows Einstein on his hesitating path from a static to the expanding universe. Contrary to an often advocated belief the primary motive for his switch was not observational evidence, but the realisation that his static model was unstable.
Interstellar Scattering and the Einstein Ring PKS 1830-211
NASA Technical Reports Server (NTRS)
Jones, D. L.; Preston, R. A.; Murphy, D. W.; Meier, D. L.; Jauncey, D. L.; Reynolds, J. E.; Tziomis, A. K.
1995-01-01
High frequency (22 GHz) data have been used two resolve two compact components of the strong gravitational lens PKS 1830-211. The two bright components are at opposite sides of a one arcsecond diameter Einstein ring.
A New Measurement of Time: The Einstein System.
ERIC Educational Resources Information Center
Aragon, Mario Rodriguez
1979-01-01
Analyzes the concepts of physical time and of the measurement of the magnitude of time, and examines the International System of Units (SI). A proposal for the use of the Einstein system (ES) is also included. (HM)
New exact perfect fluid solutions of Einstein's equations. II
NASA Astrophysics Data System (ADS)
Uggla, Claes; Rosquist, Kjell
1990-12-01
A family of new spatially homogeneous Bianchi type VIh perfect fluid solutions of the Einstein equations is presented. The fluid flow is orthogonal to the spatially homogeneous hypersurfaces, and the pressure is proportional to the energy density.
A comparative analysis of perspectives of Mileva Maric Einstein
NASA Astrophysics Data System (ADS)
Barnett, Carol C.
This dissertation examines the controversy surrounding Mileva Maric Einstein and the allegations subsequent to the publication of love letters during the time that Mileva Maric and Albert Einstein were students and during the early years of their marriage. It also examines the role of women in science from a historical perspective. Chapter One surveys the history of women in science from antiquity to the late nineteenth century and the patterns of gender related and restricting practices such as education, publication, the problem of mentoring and the issue of the lack of historical recognition. Chapter Two provides a comparative analyses between the lives of Mileva Maric Einstein and Marie Sklodowska Curie. Both had very similar social and educational backgrounds yet Marie Curie was able to work and publish jointly with her husband and received (although belatedly) international recognition for her work. On the other hand, Mileva Maric Einstein was never able to complete her degree and lived a life of obscurity and unfulfilled professional dreams. Both highly educated and intelligent women, but with drastically different outcomes in their professional and personal lives. Chapter Three examines the one book devoted to the life of Mileva Maric Einstein, Im Schatten Albert Einsteins: Das Tragische Leben der Mileva Einstein-Maric (In The Shadow of Albert Einstein: The Tragic Life of Mileva Maric), by Desanka Trbuhovic-Gjuric, Paul Haupt Publishers, 1985. It addresses the subjective as well as constructive and destructive criticisms of the various critical camps and provides examples of the statements made by the author which prompted a controversy within the academic and scientific communities. Appropriate responses are provided from various members of the scientific community to reflect the diversity of opinion and the intensity of the debate. Chapter Four addresses the problem of historicity and various interpretations of evidence which might suggest that the role
Nonequilibrium Bose-Einstein condensation of hot magnons
Vannucchi, Fabio Stucchi; Vasconcellos, Aurea Rosas; Luzzi, Roberto
2010-10-01
We present an analysis of the emergence of a nonequilibrium Bose-Einstein-type condensation of magnons in radio-frequency pumped magnetic thin films, which has recently been experimentally observed. A complete description of all the nonequilibrium processes involved is given. It is demonstrated that the phenomenon is another example of the emergence of Bose-Einstein-type condensation in nonequilibrium many-boson systems embedded in a thermal bath, a phenomenon evidenced decades ago by the renowned late Herbert Froehlich.
Soliton Creation During a Bose-Einstein Condensation
Damski, Bogdan; Zurek, Wojciech H.
2010-04-23
We use the stochastic Gross-Pitaevskii equation to study dynamics of Bose-Einstein condensation. We show that cooling into a Bose-Einstein condensate (BEC) can create solitons with density given by the cooling rate and by the critical exponents of the transition. Thus, counting solitons left in its wake should allow one to determine the critical exponents z and {nu} for a BEC phase transition. The same information can be extracted from two-point correlation functions.
Phase separation of two-component Bose-Einstein condensates
Liu, Zuhan
2009-10-15
Recently, coupled systems of nonlinear Schroedinger equations have been used extensively to describe mixtures Bose-Einstein condensates. In this paper, we study the distribution of two different hyperfine spin states of a binary mixture of three dimensional Bose-Einstein condensates. In a double condensate, an interface may occur due to large intraspecies and interspecies scattering lengths. We prove that there is an asymptotic separation of different phases in the strong coupling (Thomas-Fermi) limit.
Einstein's investigations of Galilean covariant electrodynamics prior to 1905
NASA Astrophysics Data System (ADS)
Norton, John D.
2004-11-01
Einstein learned from the magnet and conductor thought experiment how to use field transformation laws to extend the covariance of Maxwells electrodynamics. If he persisted in his use of this device, he would have found that the theory cleaves into two Galilean covariant parts, each with different field transformation laws. The tension between the two parts reflects a failure not mentioned by Einstein: that the relativity of motion manifested by observables in the magnet and conductor thought experiment does not extend to all observables in electrodynamics. An examination of Ritz's work shows that Einstein's early view could not have coincided with Ritz's on an emission theory of light, but only with that of a conveniently reconstructed Ritz. One Ritz-like emission theory, attributed by Pauli to Ritz, proves to be a natural extension of the Galilean covariant part of Maxwell's theory that happens also to accommodate the magnet and conductor thought experiment. Einstein's famous chasing a light beam thought experiment fails as an objection to an ether-based, electrodynamical theory of light. However it would allow Einstein to formulate his general objections to all emission theories of light in a very sharp form. Einstein found two well known experimental results of 18th and 19th century optics compelling (Fizeau's experiment, stellar aberration), while the accomplished Michelson-Morley experiment played no memorable role. I suggest they owe their importance to their providing a direct experimental grounding for Lorentz' local time, the precursor of Einstein's relativity of simultaneity, and doing it essentially independently of electrodynamical theory. I attribute Einstein's success to his determination to implement a principle of relativity in electrodynamics, but I urge that we not invest this stubbornness with any mystical prescience.
Differential invariants and exact solutions of the Einstein equations
NASA Astrophysics Data System (ADS)
Lychagin, Valentin; Yumaguzhin, Valeriy
2016-03-01
In this paper (cf. Lychagin and Yumaguzhin, in Anal Math Phys, 2016) a class of totally geodesics solutions for the vacuum Einstein equations is introduced. It consists of Einstein metrics of signature (1,3) such that 2-dimensional distributions, defined by the Weyl tensor, are completely integrable and totally geodesic. The complete and explicit description of metrics from these class is given. It is shown that these metrics depend on two functions in one variable and one harmonic function.
A complete public archive for the Einstein IPC
NASA Technical Reports Server (NTRS)
Helfand, David J.
1995-01-01
This report documents progress made in the period 24 Sept. 1993 - 23 Sept. 1995 on the project described in our proposal 'A Complete Public Archive for the Einstein IPC' which was approved under the Astrophysics Data Program in 1992. We have completed most of the principal objectives of the original proposal; a NFE was recently approved so that costs for publications in press can be covered and we can complete the public record for the Einstein IPC database.
Einstein's other gravity and the acceleration of the Universe
Linder, Eric V.
2010-06-15
Spacetime curvature plays the primary role in general relativity but Einstein later considered a theory where torsion was the central quantity. Just as the Einstein-Hilbert action in the Ricci curvature scalar R can be generalized to f(R) gravity, we consider extensions of teleparallel, or torsion scalar T, gravity to f(T) theories. The field equations are naturally second order, avoiding pathologies, and can give rise to cosmic acceleration with unique features.
Ferroelectricity by Bose–Einstein condensation in a quantum magnet
Kimura, S.; Kakihata, K.; Sawada, Y.; Watanabe, K.; Matsumoto, M.; Hagiwara, M.; Tanaka, H.
2016-01-01
The Bose–Einstein condensation is a fascinating phenomenon, which results from quantum statistics for identical particles with an integer spin. Surprising properties, such as superfluidity, vortex quantization or Josephson effect, appear owing to the macroscopic quantum coherence, which spontaneously develops in Bose–Einstein condensates. Realization of Bose–Einstein condensation is not restricted in fluids like liquid helium, a superconducting phase of paired electrons in a metal and laser-cooled dilute alkali atoms. Bosonic quasi-particles like exciton-polariton and magnon in solids-state systems can also undergo Bose–Einstein condensation in certain conditions. Here, we report that the quantum coherence in Bose–Einstein condensate of the magnon quasi particles yields spontaneous electric polarization in the quantum magnet TlCuCl3, leading to remarkable magnetoelectric effect. Very soft ferroelectricity is realized as a consequence of the O(2) symmetry breaking by magnon Bose–Einstein condensation. The finding of this ferroelectricity will open a new window to explore multi-functionality of quantum magnets. PMID:27666875
Symmetry and asymmetry in electrodynamics from Rowland to Einstein
NASA Astrophysics Data System (ADS)
Hon, Giora; Goldstein, Bernard R.
Halfway through the paper in which he laid down the foundations for the theory of special relativity, Einstein concludes that "the asymmetry mentioned in the Introduction … disappears." Making asymmetry disappear has proved to be one of Einstein's many significant moves in his annus mirabilis of 1905. This elimination of asymmetry has led many commentators to claim that Einstein was motivated by either an aesthetic or an epistemic argument which gives priority to symmetry over asymmetry. Following closely the development of electrodynamics in the period from 1880 to 1905 and the usage of the related terms reciprocity and symmetry, we suggest a different way of understanding Einstein's motivation and the path he took. In contrast to the received view, we argue that Einstein responded to a debate in the literature on electrodynamics and that he was concerned neither with an aesthetic nor with an epistemic argument; rather, his reasoning was physical in the best sense, and most original. We will show that by providing a new perspective on the relation between electricity and magnetism, Einstein succeeded in bringing the discussion of symmetry in electrodynamics to an end.
Symmetries and conservation laws of space-times admitting two commuting killing vectors
NASA Astrophysics Data System (ADS)
Menon, Balraj
In this dissertation, we determined all first-order generalized symmetries of the vacuum Einstein equations for spacetimes admitting two commuting Killing vector fields. The field equations for the two Killing vector models, referred to as the reduced Einstein equations, were first derived using a projection formalism first developed by Geroch. In the derivation of the reduced Einstein equations, we assumed the two-dimensional distribution orthogonal to the vector spaces spanned by the Killing vector fields admits integral submanifolds. Prior to embarking on the symmetry analysis, the reduced Einstein equations were expressed in harmonic-null coordinates. A brief survey of the theory of symmetry groups of differential equations, variational symmetries, and local conservation laws preceded the generalized symmetry analysis of the reduced Einstein equation. These concepts were motivated and presented through their application to a variety of physical systems drawn from classical mechanics, quantum mechanics, classical electromagnetism, and general relativity. We obtained partial results from a preliminary analysis of kth-order generalized symmetries (for k ≥ 1) of the reduced Einstein equations. This was followed by the determination of all first-order generalized symmetries admitted by the reduced Einstein equations. We showed that all first-order generalized symmetries of the reduced Einstein equations are, in fact, prolonged point symmetries. Since the reduced Einstein equations admit a Lagrangian formulation, the variational symmetries and local conservation laws associated with the first-order symmetries were also determined and discussed.
Rotating trapped Bose-Einstein condensates
NASA Astrophysics Data System (ADS)
Fetter, A. L.
2008-01-01
Trapped Bose-Einstein condensates (BECs) differ considerably from the standard textbook example of a uniform Bose gas. In an isotropic harmonic potential V( r) = ½ Mω2 r 2, the single-particle ground state introduces a new intrinsic scale of length [the ground-state size d = √ ℏ/( Mω)] and energy [the ground-state energy E 0 = frac{3} {2} ℏω]. When the trap rotates at a low angular velocity, the behavior of a single vortex illustrates the crucial role of discrete quantized vorticity. For more rapid rotation, the condensate contains a vortex array. The resulting centrifugal forces expand the condensate radially and shrink it axially; thus, the condensate becomes effectively two dimensional. If the external rotation speed approaches the frequency of the radial harmonic confining potential, the condensate enters the "lowest-Landau-level" regime, and a simple description again becomes possible. Eventually, the system is predicted to make a quantum phase transition to a highly correlated state analogous to the fractional quantum Hall states of electrons in a strong magnetic field.
Unification of Einstein's Gravity with Quantum Chromodynamics
NASA Astrophysics Data System (ADS)
Sarfatti, Jack
2010-02-01
The four tetrad and six spin-connection Cartan 1-forms of Einstein's GeoMetroDynamic (GMD) field emerge from the eight virtual gluon macro-quantum coherent QCD post-inflation vacuum condensates that form in the inflationary phase transition. This joint emergence of gravity and the strong force is similar to the emergence of irrotational superflow with vortex defects in liquid helium below the Lambda Point. Repulsive dark energy is from the residual random virtual bosons that did not cohere in the moment of inflation. Similarly, attractive dark matter is from the residual random virtual fermion-antifermion pairs. Therefore, I predict that the LHC will not detect any on-mass-shell real particles that can explain φDM˜0.23. As first suggested by Abdus Salam (f-gravity) the low energy tail of the nuclear force can be explained as strong short-range Yukawa gravity. QCD's IR confinement and UV asymptotic freedom are elementary consequences in this simple model. )
Nonlinear phenomena in Bose-Einstein condensates
NASA Astrophysics Data System (ADS)
Carr, Lincoln D.
2008-05-01
We present a medley of results from the last three years on nonlinear phenomena in BECs [1]. These include exact dynamics of multi-component condensates in optical lattices [2], vortices and ring solitons [3], macroscopic quantum tunneling [4], nonlinear band theory [5], and a pulsed atomic soliton laser [6]. 1. Emergent Nonlinear Phenomena in Bose-Einstein Condensates: Theory and Experiment, ed. P. G. Kevrekidis, D. J. Frantzeskakis, and R. Carretero-Gonzalez (Springer-Verlag, 2008). 2. R. Mark Bradley, James E. Bernard, and L. D. Carr, e-print arXiv:0711.1896 (2007). 3. G. Herring, L. D. Carr, R. Carretero-Gonzalez, P. G. Kevrekidis, D. J. Frantzeskakis, Phys. Rev. A in press, e-print arXiv:0709.2193 (2007); L. D. Carr and C. W. Clark, Phys. Rev. A v. 74, p.043613 (2006); L. D. Carr and C. W. Clark, Phys. Rev. Lett. v. 97, p.010403 (2006). 4. L. D. Carr, M. J. Holland, and B. A. Malomed, J. Phys. B: At. Mol. Opt. Phys., v.38, p.3217 (2005) 5. B. T. Seaman, L. D. Carr, and M. J. Holland, Phys. Rev. A, v. 71, p.033622 (2005). 6. L. D. Carr and J. Brand, Phys. Rev. A, v.70, p.033607 (2004); L. D. Carr and J. Brand, Phys. Rev. Lett., v.92, p.040401 (2004).
Curvature Interaction in Collective Space
NASA Astrophysics Data System (ADS)
Herrmann, Richard
2012-12-01
For the Riemannian space, built from the collective coordinates used within nuclear models, an additional interaction with the metric is investigated, using the collective equivalent to Einstein's curvature scalar. The coupling strength is determined using a fit with the AME2003 ground state masses. An extended finite-range droplet model including curvature is introduced, which generates significant improvements for light nuclei and nuclei in the trans-fermium region.
Gravitation theory in a fractal space-time
Agop, M.; Gottlieb, I.
2006-05-15
Assimilating the physical space-time with a fractal, a general theory is built. For a fractal dimension D=2, the virtual geodesics of this space-time implies a generalized Schroedinger type equation. Subsequently, a geometric formulation of the gravitation theory on a fractal space-time is given. Then, a connection is introduced on a tangent bundle, the connection coefficients, the Riemann curvature tensor and the Einstein field equation are calculated. It results, by means of a dilation operator, the equivalence of this model with quantum Einstein gravity.
NASA Astrophysics Data System (ADS)
Breitenlohner, Peter; Forgács, Peter; Maison, Dieter
2006-02-01
We give a complete classification of all static, spherically symmetric solutions of the SU(2) Einstein-Yang-Mills theory with a positive cosmological constant. Our classification proceeds in two steps. We first extend solutions of the radial field equations to their maximal interval of existence. In a second step we determine the Carter-Penrose diagrams of all 4-dimensional space-times constructible from such radial pieces. Based on numerical studies we sketch a complete phase space picture of all solutions with a regular origin.
Cosmology without Einstein's assumption that inertial mass produces gravity
NASA Astrophysics Data System (ADS)
Ellis, Homer G.
2015-06-01
Giving up Einstein's assumption, implicit in his 1916 field equations, that inertial mass, even in its appearance as energy, is equivalent to active gravitational mass and therefore is a source of gravity allows revising the field equations to a form in which a positive cosmological constant is seen to (mis)represent a uniform negative net mass density of gravitationally attractive and gravitationally repulsive matter. Field equations with both positive and negative active gravitational mass densities of both primordial and continuously created matter, incorporated along with two scalar fields to 'relax the constraints' on the spacetime geometry, yield cosmological solutions that exhibit inflation, deceleration, coasting, acceleration, and a 'big bounce' instead of a 'big bang,' and provide good fits to a Hubble diagram of Type Ia supernovae data. The repulsive matter is identified as the back sides of the 'drainholes' introduced by the author in 1973 as solutions of those same field equations. Drainholes (prototypical examples of 'traversable wormholes') are topological tunnels in space which gravitationally attract on their front, entrance sides, and repel more strongly on their back, exit sides. The front sides serve both as the gravitating cores of the visible, baryonic particles of primordial matter and as the continuously created, invisible particles of the 'dark matter' needed to hold together the large-scale structures seen in the universe; the back sides serve as the misnamed 'dark energy' driving the current acceleration of the expansion of the universe. Formation of cosmic voids, walls, filaments and nodes is attributed to expulsion of drainhole entrances from regions populated by drainhole exits and accumulation of the entrances on boundaries separating those regions.
Kornilovitch, P E; Hague, J P
2015-02-25
Both FeSe and cuprate superconductors are quasi 2D materials with high transition temperatures and local fermion pairs. Motivated by such systems, we investigate real space pairing of fermions in an anisotropic lattice model with intersite attraction, V, and strong local Coulomb repulsion, U, leading to a determination of the optimal conditions for superconductivity from Bose-Einstein condensation. Our aim is to gain insight as to why high temperature superconductors tend to be quasi 2D. We make both analytically and numerically exact solutions for two body local pairing applicable to intermediate and strong V. We find that the Bose-Einstein condensation temperature of such local pairs pairs is maximal when hopping between layers is intermediate relative to in-plane hopping, indicating that the quasi 2D nature of unconventional superconductors has an important contribution to their high transition temperatures. PMID:25629425
Bose-Einstein Interference in the Passage of a Jet in a Dense Medium
Wong, Cheuk-Yin
2012-01-01
When an energetic fermion collides with many fermion scatterers at very high energies, the Bose-Einstein symmetry with respect to the interchange of the virtual bosons leads to a destructive interference of the Feynman amplitude components in most regions of the momentum transfer phase space but a constructive interference in some other regions of the momentum transfer phase space. As a consequence, the recoiling scatterers have a tendency to come out collectively along the incident jet direction, each carrying a substantial fraction of the incident jet longitudinal momentum. This collective recoil of the scatterers may be the origin of the longitudinal momentum kick in the momentum kick model proposed to explain the "ridge" correlations in high-energy Pb-Pb collisions at RHIC and p-p collisions at LHC.
Asymptotically flat space-times: an enigma
NASA Astrophysics Data System (ADS)
Newman, Ezra T.
2016-07-01
We begin by emphasizing that we are dealing with standard Einstein or Einstein-Maxwell theory—absolutely no new physics has been inserted. The fresh item is that the well-known asymptotically flat solutions of the Einstein-Maxwell theory are transformed to a new coordinate system with surprising and (seemingly) inexplicable results. We begin with the standard description of (Null) asymptotically flat space-times described in conventional Bondi-coordinates. After transforming the variables (mainly the asymptotic Weyl tensor components) to a very special set of Newman-Unti (NU) coordinates, we find a series of relations totally mimicking standard Newtonian classical mechanics and Maxwell theory. The surprising and troubling aspect of these relations is that the associated motion and radiation does not take place in physical space-time. Instead these relations takes place in an unusual inherited complex four-dimensional manifold referred to as H-space that has no immediate relationship with space-time. In fact these relations appear in two such spaces, H-space and its dual space \\bar{H}.
Studying planet populations with Einstein's blip.
Dominik, Martin
2010-08-13
Although Einstein originally judged that 'there is no great chance of observing this phenomenon', the 'most curious effect' of the bending of starlight by the gravity of intervening foreground stars--now commonly referred to as 'gravitational microlensing'--has become one of the successfully applied techniques to detect planets orbiting stars other than the Sun, while being quite unlike any other. With more than 400 extra-solar planets known altogether, the discovery of a true sibling of our home planet seems to have become simply a question of time. However, in order to properly understand the origin of Earth, carrying all its various life forms, models of planet formation and orbital evolution need to be brought into agreement with the statistics of the full variety of planets like Earth and unlike Earth. Given the complementarity of the currently applied planet detection techniques, a comprehensive picture will only arise from a combination of their respective findings. Gravitational microlensing favours a range of orbital separations that covers planets whose orbital periods are too long to allow detection by other indirect techniques, but which are still too close to their host star to be detected by means of their emitted or reflected light. Rather than being limited to the Solar neighbourhood, a unique opportunity is provided for inferring a census of planets orbiting stars belonging to two distinct populations within the Milky Way, with a sensitivity not only reaching down to Earth mass, but even below, with ground-based observations. The capabilities of gravitational microlensing extend even to obtaining evidence of a planet orbiting a star in another galaxy. PMID:20603366
Newton, Einstein, Jeffreys and Bayesian model selection
NASA Astrophysics Data System (ADS)
Chettri, Samir; Batchelor, David; Campbell, William; Balakrishnan, Karthik
2005-11-01
In Jefferys and Berger apply Bayesian model selection to the problem of choosing between rival theories, in particular between Einstein's theory of general relativity (GR) and Newtonian gravity (NG). [1] presents a debate between Harold Jeffreys and Charles Poor regarding the observed 43''/century anomalous perhelion precession of Mercury. GR made a precise prediction of 42.98''/century while proponents of NG suggested several physical mechanisms that were eventually refuted, with the exception of a modified inverse square law. Using Bayes Factors (BF) and data available in 1921, shows that GR is preferable to NG by a factor of about 25 to 1. A scale for BF used by Jeffreys, suggests that this is positive to strong evidence for GR over modified NG but it is not very strong or even overwhelming. In this work we calculate the BF from the period 1921 till 1993. By 1960 we see that the BF, due to better data gathering techniques and advances in technology, had reached a factor of greater than 100 to 1, making GR strongly preferable to NG and by 1990 the BF reached 1000:1. Ironically while BF had reached a state of near certainty even in 1960 rival theories of gravitation were on the rise - notably the Brans-Dicke (BD) scalar-tensor theory of gravity. The BD theory is postulated in such a way that for small positive values of a scalar parameter ω, the BF would favor GR while the BF would approach unity with certainty as ω grows larger, at which point either theory would be prefered, i.e., it is a theory that cannot lose. Does this mean Bayesian model selection needs to be overthrown? This points to the need for cogent prior information guided by physics and physical experiment.
Nonlinear Phenomena in Bose-Einstein condensates
NASA Astrophysics Data System (ADS)
Carr, Lincoln D.
2008-03-01
We present a medley of results from the last three years on nonlinear phenomena in BECs [1]. These include exact dynamics of multi-component condensates in optical lattices [2], vortices and ring solitons [3], macroscopic quantum tunneling [4], nonlinear band theory [5], and a pulsed atomic soliton laser [6]. 1. Emergent Nonlinear Phenomena in Bose-Einstein Condensates: Theory and Experiment, ed. P. G. Kevrekidis, D. J. Frantzeskakis, and R. Carretero-Gonzalez (Springer-Verlag, to appear, 2008) -- see L. D. Carr and Joachim Brand, e-print arXiv:0705.1139 (2007); Joachim Brand, L. D. Carr, B. P. Anderson, e-print arXiv:0705.1341 (2007). 2. R. Mark Bradley, James E. Bernard, and L. D. Carr, e-print arXiv:0711.1896 (2007). 3. G. Herring, L. D. Carr, R. Carretero-Gonzalez, P. G. Kevrekidis, D. J. Frantzeskakis, e-print arXiv:0709.2193 (2007); L. D. Carr and C. W. Clark, Phys. Rev. A v. 74, p.043613 (2006); L. D. Carr and C. W. Clark, Phys. Rev. Lett. v. 97, p.010403 (2006). 4. L. D. Carr, M. J. Holland, and B. A. Malomed, J. Phys. B: At. Mol. Opt. Phys., v.38, p.3217 (2005) 5. B. T. Seaman, L. D. Carr, and M. J. Holland, Phys. Rev. A, v. 71, p.033622 (2005). 6. L. D. Carr and J. Brand, Phys. Rev. A, v.70, p.033607 (2004); L. D. Carr and J. Brand, Phys. Rev. Lett., v.92, p.040401 (2004).
Echoing Citizen Einstein in the East: Andrei Sakharov
NASA Astrophysics Data System (ADS)
Rhéaume, Charles
2006-11-01
As if a handing of the torch, Andrei Sakharov saw his dissidence acquire initial impetus from nuclear tests that it was clear were becoming out of control in the hands of an unscrupulous regime in 1955, the very year Einstein died. He had of course drawn from the latter's science for the realization of the Soviet H-bomb. From then on, however, it would be the humanistic views of Einstein that would lead his way. Not only was he not an anti-Semite like many in official circles in the Soviet Union at the time but through experiences in his young age and later in his work on the bomb where he had many Jewish colleagues, Sakharov had come to admire Jewish culture and particularly its inclination towards intellectual life. It was with a fully open mind then that he got acquainted with Einstein's ideas on how the great man saw the world. Sakharov would divulge his own vision of the world in an essay titled "Progress, Peaceful Coexistence and Intellectual Freedom" in 1968. The Albert Einstein Peace Prize he would be awarded in 1988 for his relentless advocacy of peace would come as a confirmation of the spiritual linkage between the two men. This paper scrutinizes traces of Einstein's thinking in Sakharov's own. It focuses particularly on their convergent understanding of the notion of world government.
A comment on Mermin's "Understanding Einstein's 1905 derivation of E=mc2"
NASA Astrophysics Data System (ADS)
Ohanian, Hans C.
2012-08-01
N. D. Mermin has proposed an "elaboration" of Einstein's 1905 derivation that supposedly fixes the flaws that I identified in this derivation. By specific examples taken from Einstein's own later work, I show that Mermin's elaboration is fraught with misconceptions.
Generating time dependent conformally coupled Einstein-scalar solutions
NASA Astrophysics Data System (ADS)
Sultana, Joseph
2015-07-01
Using the correspondence between a minimally coupled scalar field and an effective stiff perfect fluid with or without a cosmological constant, we present a simple method for generating time dependent Einstein-scalar solutions with a conformally coupled scalar field that has vanishing or non-vanishing potential. This is done by using Bekenstein's transformation on Einstein-scalar solutions with minimally coupled massless scalar fields, and its later generalization by Abreu et al. to massive fields. In particular we obtain two new spherically symmetric time dependent solutions to the coupled system of Einstein's and the conformal scalar field equations, with one of the solutions having a Higgs' type potential for the scalar field, and we study their properties.
Radiating black hole solutions in Einstein-Gauss-Bonnet gravity
Dominguez, Alfredo E.; Gallo, Emanuel
2006-03-15
In this paper, we find some new exact solutions to the Einstein-Gauss-Bonnet equations. First, we prove a theorem which allows us to find a large family of solutions to the Einstein-Gauss-Bonnet gravity in n-dimensions. This family of solutions represents dynamic black holes and contains, as particular cases, not only the recently found Vaidya-Einstein-Gauss-Bonnet black hole, but also other physical solutions that we think are new, such as the Gauss-Bonnet versions of the Bonnor-Vaidya (de Sitter/anti-de Sitter) solution, a global monopole, and the Husain black holes. We also present a more general version of this theorem in which less restrictive conditions on the energy-momentum tensor are imposed. As an application of this theorem, we present the exact solution describing a black hole radiating a charged null fluid in a Born-Infeld nonlinear electrodynamics.
General relativistic magneto-hydrodynamics with the Einstein Toolkit
NASA Astrophysics Data System (ADS)
Moesta, Philipp; Mundim, Bruno; Faber, Joshua; Noble, Scott; Bode, Tanja; Haas, Roland; Loeffler, Frank; Ott, Christian; Reisswig, Christian; Schnetter, Erik
2013-04-01
The Einstein Toolkit Consortium is developing and supporting open software for relativistic astrophysics. Its aim is to provide the core computational tools that can enable new science, broaden our community, facilitate interdisciplinary research and take advantage of petascale computers and advanced cyberinfrastructure. The Einstein Toolkit currently consists of an open set of over 100 modules for the Cactus framework, primarily for computational relativity along with associated tools for simulation management and visualization. The toolkit includes solvers for vacuum spacetimes as well as relativistic magneto-hydrodynamics. This talk will present the current capabilities of the Einstein Toolkit with a particular focus on recent improvements made to the general relativistic magneto-hydrodynamics modeling and will point to information how to leverage it for future research.
Entanglement of two-mode Bose-Einstein condensates
Hines, Andrew P.; McKenzie, Ross H.; Milburn, Gerard J.
2003-01-01
We investigate the entanglement characteristics of two general bimodal Bose-Einstein condensates--a pair of tunnel-coupled Bose-Einstein condensates and the atom-molecule Bose-Einstein condensate. We argue that the entanglement is only physically meaningful if the system is viewed as a bipartite system, where the subsystems are the two modes. The indistinguishibility of the particles in the condensate means that the atomic constituents are physically inaccessible and, thus, the degree of entanglement between individual particles, unlike the entanglement between the modes, is not experimentally relevant so long as the particles remain in the condensed state. We calculate the entanglement between the two modes for the exact ground state of the two bimodal condensates and consider the dynamics of the entanglement in the tunnel-coupled cas000.
Vortex formation in a fast rotating Bose-Einstein condensate
Ghosh, Tarun Kanti
2004-04-01
We study rotational motion of an interacting atomic Bose-Einstein condensate confined in a quadratic-plus-quartic potential. We calculate the lowest energy surface mode frequency and show that a symmetric trapped (harmonic and quartic) Bose-Einstein condensate breaks the rotational symmetry of the Hamiltonian when rotational frequency is greater than one-half of the lowest energy surface mode frequency. We argue that the formation of a vortex is not possible in a noninteracting as well as in an attractive Bose-Einstein condensate confined in a harmonic trap due to the absence of the spontaneous shape deformation, but it can occur which leads to the vortex formation if we add an additional quartic potential. Moreover, the spontaneous shape deformation and consequently the formation of a vortex in an attractive system depends on the strengths of the two-body interaction and the quartic potential.
Albert Einstein and Friedrich Dessauer: Political Views and Political Practice
NASA Astrophysics Data System (ADS)
Goenner, Hubert
In this case study I compare the political views of the physicists Albert Einstein and Friedrich Dessauer between the first and second world wars, and I investigate their translation into concrete political practice. Both departed from their roles as experts in physics in favor of political engagement. The essence of Einstein's political practice seems to have been a form of political participation in exerting moral influence on people and organizations through public declarations and appeals in isolation from political mass movements. Dessauer exerted political influence both through public office (as a member of Parliament for the Catholic Center Party) and by acquiring a newspaper. The different political practice of both Einstein and Dessauer were unsuccessful in thwarting the Nazi takeover.
The Stokes-Einstein relation at moderate Schmidt number.
Balboa Usabiaga, Florencio; Xie, Xiaoyi; Delgado-Buscalioni, Rafael; Donev, Aleksandar
2013-12-01
The Stokes-Einstein relation for the self-diffusion coefficient of a spherical particle suspended in an incompressible fluid is an asymptotic result in the limit of large Schmidt number, that is, when momentum diffuses much faster than the particle. When the Schmidt number is moderate, which happens in most particle methods for hydrodynamics, deviations from the Stokes-Einstein prediction are expected. We study these corrections computationally using a recently developed minimally resolved method for coupling particles to an incompressible fluctuating fluid in both two and three dimensions. We find that for moderate Schmidt numbers the diffusion coefficient is reduced relative to the Stokes-Einstein prediction by an amount inversely proportional to the Schmidt number in both two and three dimensions. We find, however, that the Einstein formula is obeyed at all Schmidt numbers, consistent with linear response theory. The mismatch arises because thermal fluctuations affect the drag coefficient for a particle due to the nonlinear nature of the fluid-particle coupling. The numerical data are in good agreement with an approximate self-consistent theory, which can be used to estimate finite-Schmidt number corrections in a variety of methods. Our results indicate that the corrections to the Stokes-Einstein formula come primarily from the fact that the particle itself diffuses together with the momentum. Our study separates effects coming from corrections to no-slip hydrodynamics from those of finite separation of time scales, allowing for a better understanding of widely observed deviations from the Stokes-Einstein prediction in particle methods such as molecular dynamics.
Unified Maxwell-Einstein and Yang-Mills-Einstein supergravity theories in four dimensions
NASA Astrophysics Data System (ADS)
Günaydin, Murat; McReynolds, Sean; Zagermann, Marco
2005-09-01
We study unified Script N = 2 Maxwell-Einstein supergravity theories (MESGTs) and unified Yang-Mills Einstein supergravity theories (YMESGTs) in four dimensions. As their defining property, these theories admit the action of a global or local symmetry group that is (i) simple, and (ii) acts irreducibly on all the vector fields of the theory, including the ``graviphoton''. Restricting ourselves to the theories that originate from five dimensions via dimensional reduction, we find that the generic Jordan family of MESGTs with the scalar manifolds Script M = [SU(1,1)/U(1)]×[SO(2,n)/SO(2)×SO(n)] are all unified in four dimensions with the unifying global symmetry group SO(2,n). Of these theories only one can be gauged so as to obtain a unified YMESGT with the gauge group SO(2,1). Three of the four magical supergravity theories defined by simple euclidean Jordan algebras J3Bbb A(Bbb A = Bbb C,Bbb H,Bbb O) of degree 3 are unified MESGTs in four dimensions. The MESGTs defined by J3Bbb C and J3Bbb O can furthermore be gauged so as to obtain a 4D unified YMESGT with gauge groups SO(3,2) and SO(6,2), respectively. The generic non-Jordan family and the theories whose scalar manifolds are homogeneous but not symmetric do not lead to unified MESGTs in four dimensions. The three infinite families of unified five-dimensional MESGTs defined by simple lorentzian Jordan algebras of degree p≠4, whose scalar manifolds are non-homogeneous, do not lead directly to unified MESGTs in four dimensions under dimensional reduction. However, since their manifolds are non-homogeneous we are not able to completely rule out the existence of symplectic sections in which these theories become unified in four dimensions.
Albert Einstein and LD: an evaluation of the evidence.
Thomas, M
2000-01-01
Historical figures suspected of having learning disabilities are often subjected to retrospective diagnoses. One such figure is Albert Einstein. Several organizations that promote the interests of individuals with learning disabilities claim that Einstein had a learning disability. A review of biographical sources, however, provides little or no evidence to support this claim. The claim derives its force not from evidence but from a powerful belief--that the greatest among us suffer from some impairment--and from an equally powerful desire to enhance the status of a marginalized group by including within it exceptional individuals.
Einstein x-ray observations of cataclysmic variables
Mason, K.O.; Cordova, F.A.
1982-01-01
Observations with the imaging x-ray detectors on the Einstein Observatory have led to a large increase in the number of low luminosity x-ray sources known to be associated with cataclysmic variable stars (CVs). The high sensitivity of the Einstein instrumentation has permitted study of their short timescale variability and spectra. The data are adding significantly to our knowledge of the accretion process in cataclysmic variables and forcing some revision in our ideas concerning the origin of the optical variability in these stars.
Charged Einstein-aether black holes and Smarr formula
NASA Astrophysics Data System (ADS)
Ding, Chikun; Wang, Anzhong; Wang, Xinwen
2015-10-01
In the framework of the Einstein-Maxwell-aether theory, we present two new classes of exact charged black hole solutions, which are asymptotically flat and possess the universal as well as Killing horizons. We also construct the Smarr formulas and calculate the temperatures of the horizons, using the Smarr mass-area relation. We find that, in contrast to the neutral case, a temperature obtained this way is not proportional to its surface gravity at either of the two types of horizons. Einstein-Maxwell-aether black holes with the cosmological constant and their topological cousins are also presented.
The Einstein field equation in a multidimensional universe.
NASA Astrophysics Data System (ADS)
Pekonen, Osmo
1988-07-01
String theory [4] predicts that the universe has 10 or 26 dimensions. A salient problem is how the Einstein field equation should be written in terms of these revivified Kaluza-Klein cosmologies. The answer is by now well-known, yet nobody seems to have rewritten the seminal computation in [6] where an unnecessarily involved Euler-Lagrange variational method is employed and, curiously enough, no allusion to the Gauss-Bonnet-Chern theorem is made. We provide a more straightforward argument, which has been inspired by Hilbert's original derivation of the Einstein field equation [5].
Modeling Bose-Einstein correlations via elementary emitting cells
Utyuzh, Oleg; Wilk, Grzegorz; Wlodarczyk, Zbigniew
2007-04-01
We propose a method of numerical modeling Bose-Einstein correlations by using the notion of the elementary emitting cell (EEC). They are intermediary objects containing identical bosons and are supposed to be produced independently during the hadronization process. Only bosons in the EEC, which represents a single quantum state here, are subjected to the effects of Bose-Einstein (BE) statistics, which forces them to follow a geometrical distribution. There are no such effects between particles from different EECs. We illustrate our proposition by calculating a representative number of typical distributions and discussing their sensitivity to EECs and their characteristics.
Perturbative Solutions of the Einstein Klein-Gordon Equations
NASA Astrophysics Data System (ADS)
Puliti, Gianluca; Jennings, Mara; Mamo, Vincent; Vuille, Chris
2005-11-01
As the Klein-Gordon equation is important in quantum theory and describes spin-0 particles, it is of interest to discover the nature of the gravity field such particles would be expected to create. In this paper, we solve the static, massive Einstein-Klein-Gordon (EKG) equations in perturbation, and compare the results with a similar calculation developed for the Einstein-Proca system. Subsequently, we study the massless static Klein-Gordon equation, and compare the result to the Reissner-Nordstrom metric.
Impurities in Bose-Einstein Condensates: From Polaron to Soliton.
Shadkhoo, Shahriar; Bruinsma, Robijn
2015-09-25
We propose that impurities in a Bose-Einstein condensate which is coupled to a transversely laser-pumped multimode cavity form an experimentally accessible and analytically tractable model system for the study of impurities solvated in correlated liquids and the breakdown of linear-response theory [corrected]. As the strength of the coupling constant between the impurity and the Bose-Einstein condensate is increased, which is possible through Feshbach resonance methods, the impurity passes from a large to a small polaron state, and then to an impurity-soliton state. This last transition marks the breakdown of linear-response theory.
Einstein, social responsibility of physicists and human rights in China
NASA Astrophysics Data System (ADS)
Fang, Li-Zhi
2005-03-01
Since Einstein first visited Shanghai on 1922, he was deeply and constantly concerned about the cases of injustice, suppression, and human rights abuses in China. The strong sense of social responsibility shown by Einstein is an illustrious role model for Chinese intellectual, especially physicists, who advocate the universal principle of human rights. I will briefly review this history. I will also briefly report what have been done and is doing by Chinese physicists in the long and difficult journey toward democracy and human rights of China.
Einstein's Photoemission from Quantum Confined Superlattices.
Debbarma, S; Ghatak, K P
2016-01-01
This paper is dedicated to the 83th Birthday of Late Professor B. R. Nag, D.Sc., formerly Head of the Departments of Radio Physics and Electronics and Electronic Science of the University of Calcutta, a firm believer of the concept of theoretical minimum of Landau and an internationally well known semiconductor physicist, to whom the second author remains ever grateful as a student and research worker from 1974-2004. In this paper, an attempt is made to study, the Einstein's photoemission (EP) from III-V, II-VI, IV-VI, HgTe/CdTe and strained layer quantum well heavily doped superlattices (QWHDSLs) with graded interfaces in the presence of quantizing magnetic field on the basis of newly formulated electron dispersion relations within the frame work of k · p formalism. The EP from III-V, II-VI, IV-VI, HgTe/CdTe and strained layer quantum wells of heavily doped effective mass superlattices respectively has been presented under magnetic quantization. Besides the said emissions, from the quantum dots of the aforementioned heavily doped SLs have further investigated for the purpose of comparison and complete investigation in the context of EP from quantum confined superlattices. Using appropriate SLs, it appears that the EP increases with increasing surface electron concentration and decreasing film thickness in spiky manners, which are the characteristic features of such quantized hetero structures. Under magnetic quantization, the EP oscillates with inverse quantizing magnetic field due to Shuvnikov-de Haas effect. The EP increases with increasing photo energy in a step-like manner and the numerical values of EP with all the physical variables are totally band structure dependent for all the cases. The most striking features are that the presence of poles in the dispersion relation of the materials in the absence of band tails create the complex energy spectra in the corresponding HD constituent materials of such quantum confined superlattices and effective electron
The Einstein@Home Search for Radio Pulsars and PSR J2007+2722 Discovery
NASA Astrophysics Data System (ADS)
Allen, B.; Knispel, B.; Cordes, J. M.; Deneva, J. S.; Hessels, J. W. T.; Anderson, D.; Aulbert, C.; Bock, O.; Brazier, A.; Chatterjee, S.; Demorest, P. B.; Eggenstein, H. B.; Fehrmann, H.; Gotthelf, E. V.; Hammer, D.; Kaspi, V. M.; Kramer, M.; Lyne, A. G.; Machenschalk, B.; McLaughlin, M. A.; Messenger, C.; Pletsch, H. J.; Ransom, S. M.; Stairs, I. H.; Stappers, B. W.; Bhat, N. D. R.; Bogdanov, S.; Camilo, F.; Champion, D. J.; Crawford, F.; Desvignes, G.; Freire, P. C. C.; Heald, G.; Jenet, F. A.; Lazarus, P.; Lee, K. J.; van Leeuwen, J.; Lynch, R.; Papa, M. A.; Prix, R.; Rosen, R.; Scholz, P.; Siemens, X.; Stovall, K.; Venkataraman, A.; Zhu, W.
2013-08-01
Einstein@Home aggregates the computer power of hundreds of thousands of volunteers from 193 countries, to search for new neutron stars using data from electromagnetic and gravitational-wave detectors. This paper presents a detailed description of the search for new radio pulsars using Pulsar ALFA survey data from the Arecibo Observatory. The enormous computing power allows this search to cover a new region of parameter space; it can detect pulsars in binary systems with orbital periods as short as 11 minutes. We also describe the first Einstein@Home discovery, the 40.8 Hz isolated pulsar PSR J2007+2722, and provide a full timing model. PSR J2007+2722's pulse profile is remarkably wide with emission over almost the entire spin period. This neutron star is most likely a disrupted recycled pulsar, about as old as its characteristic spin-down age of 404 Myr. However, there is a small chance that it was born recently, with a low magnetic field. If so, upper limits on the X-ray flux suggest but cannot prove that PSR J2007+2722 is at least ~100 kyr old. In the future, we expect that the massive computing power provided by volunteers should enable many additional radio pulsar discoveries.
Thermodynamics of rotating black branes in (n+1)-dimensional Einstein-Born-Infeld gravity
Dehghani, M. H.; Sedehi, H. R. Rastegar
2006-12-15
We construct a new class of charged rotating solutions of (n+1)-dimensional Einstein-Born-Infeld gravity with cylindrical or toroidal horizons in the presence of cosmological constant and investigate their properties. These solutions are asymptotically (anti)-de Sitter and reduce to the solutions of Einstein-Maxwell gravity as the Born-Infeld parameters goes to infinity. We find that these solutions can represent black branes, with inner and outer event horizons, an extreme black brane or a naked singularity provided the parameters of the solutions are chosen suitably. We compute temperature, mass, angular momentum, entropy, charge and electric potential of the black brane solutions. We obtain a Smarr-type formula and show that these quantities satisfy the first law of thermodynamics. We also perform a stability analysis by computing the heat capacity and the determinant of Hessian matrix of mass of the system with infinite boundary with respect to its thermodynamic variables in both the canonical and the grand-canonical ensembles, and show that the system is thermally stable in the whole phase space. Also, we find that there exists an unstable phase when the finite size effect is taken into account.
THE EINSTEIN-HOME SEARCH FOR RADIO PULSARS AND PSR J2007+2722 DISCOVERY
Allen, B.; Knispel, B.; Aulbert, C.; Bock, O.; Eggenstein, H. B.; Fehrmann, H.; Machenschalk, B.; Cordes, J. M.; Brazier, A.; Chatterjee, S.; Deneva, J. S.; Hessels, J. W. T.; Anderson, D.; Demorest, P. B.; Gotthelf, E. V.; Hammer, D.; Kaspi, V. M.; Kramer, M.; Lyne, A. G.; McLaughlin, M. A.; and others
2013-08-20
Einstein-Home aggregates the computer power of hundreds of thousands of volunteers from 193 countries, to search for new neutron stars using data from electromagnetic and gravitational-wave detectors. This paper presents a detailed description of the search for new radio pulsars using Pulsar ALFA survey data from the Arecibo Observatory. The enormous computing power allows this search to cover a new region of parameter space; it can detect pulsars in binary systems with orbital periods as short as 11 minutes. We also describe the first Einstein-Home discovery, the 40.8 Hz isolated pulsar PSR J2007+2722, and provide a full timing model. PSR J2007+2722's pulse profile is remarkably wide with emission over almost the entire spin period. This neutron star is most likely a disrupted recycled pulsar, about as old as its characteristic spin-down age of 404 Myr. However, there is a small chance that it was born recently, with a low magnetic field. If so, upper limits on the X-ray flux suggest but cannot prove that PSR J2007+2722 is at least {approx}100 kyr old. In the future, we expect that the massive computing power provided by volunteers should enable many additional radio pulsar discoveries.
Bell's theorem and the problem of decidability between the views of Einstein and Bohr.
Hess, K; Philipp, W
2001-12-01
Einstein, Podolsky, and Rosen (EPR) have designed a gedanken experiment that suggested a theory that was more complete than quantum mechanics. The EPR design was later realized in various forms, with experimental results close to the quantum mechanical prediction. The experimental results by themselves have no bearing on the EPR claim that quantum mechanics must be incomplete nor on the existence of hidden parameters. However, the well known inequalities of Bell are based on the assumption that local hidden parameters exist and, when combined with conflicting experimental results, do appear to prove that local hidden parameters cannot exist. This fact leaves only instantaneous actions at a distance (called "spooky" by Einstein) to explain the experiments. The Bell inequalities are based on a mathematical model of the EPR experiments. They have no experimental confirmation, because they contradict the results of all EPR experiments. In addition to the assumption that hidden parameters exist, Bell tacitly makes a variety of other assumptions; for instance, he assumes that the hidden parameters are governed by a single probability measure independent of the analyzer settings. We argue that the mathematical model of Bell excludes a large set of local hidden variables and a large variety of probability densities. Our set of local hidden variables includes time-like correlated parameters and a generalized probability density. We prove that our extended space of local hidden variables does permit derivation of the quantum result and is consistent with all known experiments.
EPR before EPR: A 1930 Einstein-Bohr thought Experiment Revisited
ERIC Educational Resources Information Center
Nikolic, Hrvoje
2012-01-01
In 1930, Einstein argued against the consistency of the time-energy uncertainty relation by discussing a thought experiment involving a measurement of the mass of the box which emitted a photon. Bohr seemingly prevailed over Einstein by arguing that Einstein's own general theory of relativity saves the consistency of quantum mechanics. We revisit…
Kandrup, H.E. ); Morrison, P.J. . Inst. for Fusion Studies)
1992-11-01
The Hamiltonian formulation of the Vlasov-Einstein system, which is appropriate for collisionless, self-gravitating systems like clusters of stars that are so dense that gravity must be described by the Einstein equation, is presented. In particular, it is demonstrated explicitly in the context of a 3 + 1 splitting that, for spherically symmetric configurations, the Vlasov-Einstein system can be viewed as a Hamiltonian system, where the dynamics is generated by a noncanonical Poisson bracket, with the Hamiltonian generating the evolution of the distribution function f (a noncanonical variable) being the conserved ADM mass-energy H[sub ADM]. An explicit expression is derived for the energy [delta]([sup 2])H[sub ADM] associated with an arbitrary phase space preserving perturbation of an arbitrary spherical equilibrium, and it is shown that the equilibrium must be linearly stable if [delta]([sup 2])H[sub ADM] is positive semi-definite. Insight into the Hamiltonian reformulation is provided by a description of general finite degree of freedom systems.
Kandrup, H.E.; Morrison, P.J.
1992-11-01
The Hamiltonian formulation of the Vlasov-Einstein system, which is appropriate for collisionless, self-gravitating systems like clusters of stars that are so dense that gravity must be described by the Einstein equation, is presented. In particular, it is demonstrated explicitly in the context of a 3 + 1 splitting that, for spherically symmetric configurations, the Vlasov-Einstein system can be viewed as a Hamiltonian system, where the dynamics is generated by a noncanonical Poisson bracket, with the Hamiltonian generating the evolution of the distribution function f (a noncanonical variable) being the conserved ADM mass-energy H{sub ADM}. An explicit expression is derived for the energy {delta}({sup 2})H{sub ADM} associated with an arbitrary phase space preserving perturbation of an arbitrary spherical equilibrium, and it is shown that the equilibrium must be linearly stable if {delta}({sup 2})H{sub ADM} is positive semi-definite. Insight into the Hamiltonian reformulation is provided by a description of general finite degree of freedom systems.
Bose-Einstein-condensate heating by atomic losses
Dziarmaga, Jacek; Sacha, Krzysztof
2003-10-01
Atomic Bose-Einstein condensate is heated by atomic losses. The losses act as a heat reservoir for the condensate. The condensate is approaching a state of thermal equilibrium with a thermal depletion ranging from 1% for a uniform three-dimensional (3D) condensate to around 13% for a quasi-1D condensate in a harmonic trap.
Einstein's Tea Leaves and Pressure Systems in the Atmosphere
ERIC Educational Resources Information Center
Tandon, Amit; Marshall, John
2010-01-01
Tea leaves gather in the center of the cup when the tea is stirred. In 1926 Einstein explained the phenomenon in terms of a secondary, rim-to-center circulation caused by the fluid rubbing against the bottom of the cup. This explanation can be connected to air movement in atmospheric pressure systems to explore, for example, why low-pressure…
Molecular Volumes and the Stokes-Einstein Equation
ERIC Educational Resources Information Center
Edward, John T.
1970-01-01
Examines the limitations of the Stokes-Einstein equation as it applies to small solute molecules. Discusses molecular volume determinations by atomic increments, molecular models, molar volumes of solids and liquids, and molal volumes. Presents an empirical correction factor for the equation which applies to molecular radii as small as 2 angstrom…
Static Solutions of Einstein's Equations with Cylindrical Symmetry
ERIC Educational Resources Information Center
Trendafilova, C. S.; Fulling, S. A.
2011-01-01
In analogy with the standard derivation of the Schwarzschild solution, we find all static, cylindrically symmetric solutions of the Einstein field equations for vacuum. These include not only the well-known cone solution, which is locally flat, but others in which the metric coefficients are powers of the radial coordinate and the spacetime is…
Entanglement Properties in Two-Component Bose-Einstein Condensate
NASA Astrophysics Data System (ADS)
Jiang, Di-You
2016-10-01
We investigate entanglement inseparability and bipartite entanglement of in two-component Bose-Einstein condensate in the presence of the nonlinear interatomic interaction, interspecies interaction. Entanglement inseparability and bipartite entanglement have the similar properties. More entanglement can be generated by adjusting the nonlinear interatomic interaction and control the time interval of the entanglement by adjusting interspecies interaction.
Stability analysis for n-component Bose-Einstein condensate
Roberts, David C.; Ueda, Masahito
2006-05-15
We derive the dynamic and thermodynamic stability conditions for dilute multicomponent Bose-Einstein condensates (BECs). These stability conditions, generalized for n-component BECs, are found to be equivalent and are shown to be consistent with the phase diagrams of two- and three-component condensates that are derived from energetic arguments.
Excision technique in constrained formulations of Einstein equations: collapse scenario
NASA Astrophysics Data System (ADS)
Cordero-Carrión, I.; Vasset, N.; Novak, J.; Jaramillo, J. L.
2015-04-01
We present a new excision technique used in constrained formulations of Einstein equations to deal with black hole in numerical simulations. We show the applicability of this scheme in several scenarios. In particular, we present the dynamical evolution of the collapse of a neutron star to a black hole, using the CoCoNuT code and this excision technique.
The Lorentz Theory of Electrons and Einstein's Theory of Relativity
ERIC Educational Resources Information Center
Goldberg, Stanley
1969-01-01
Traces the development of Lorentz's theory of electrons as applied to the problem of the electrodynamics of moving bodies. Presents evidence that the principle of relativity did not play an important role in Lorentz's theory, and that though Lorentz eventually acknowledged Einstein's work, he was unwilling to completely embrace the Einstein…
On Einstein, Light Quanta, Radiation, and Relativity in 1905
ERIC Educational Resources Information Center
Miller, Arthur I.
1976-01-01
Analyzes section 8 of Einstein's relativity paper of 1905, "On the Electrodynamics of Moving Bodies," in its historical context. Relates this section to the rest of the relativity paper, to the genesis of relativity theory, and to contemporaneous work on radiation theory. (Author/MLH)
Bose-Einstein correlation within the framework of hadronic mechanics
Burande, Chandrakant S.
2015-03-10
The Bose-Einstein correlation is the phenomenon in which protons and antiprotons collide at extremely high energies; coalesce one into the other resulting into the fireball of finite dimension. They annihilate each other and produces large number of mesons that remain correlated at distances very large compared to the size of the fireball. It was believed that Einstein’s special relativity and relativistic quantum mechanics are the valid frameworks to represent this phenomenon. Although, these frameworks are incomplete and require arbitrary parameters (chaoticity) to fit the experimental data which are prohibited by the basic axioms of relativistic quantum mechanics, such as that for the vacuum expectation values. Moreover, correlated mesons can not be treated as a finite set of isolated point-like particles because it is non-local event due to overlapping of wavepackets. Therefore, the Bose-Einstein correlation is incompatible with the axiom of expectation values of quantum mechanics. In contrary, relativistic hadronic mechanics constructed by Santilli allows an exact representation of the experimental data of the Bose-Einstein correlation and restore the validity of the Lorentz and Poincare symmetries under nonlocal and non-Hamiltonian internal effects. Further, F. Cardone and R. Mignani observed that the Bose-Einstein two-point correlation function derived by Santilli is perfectly matched with experimental data at high energy.
Wormholes in dilatonic Einstein-Gauss-Bonnet theory.
Kanti, Panagiota; Kleihaus, Burkhard; Kunz, Jutta
2011-12-30
We construct traversable wormholes in dilatonic Einstein-Gauss-Bonnet theory in four spacetime dimensions, without needing any form of exotic matter. We determine their domain of existence, and show that these wormholes satisfy a generalized Smarr relation. We demonstrate linear stability with respect to radial perturbations for a subset of these wormholes.
"Bohr and Einstein": A Course for Nonscience Students
ERIC Educational Resources Information Center
Schlegel, Richard
1976-01-01
A study of the concepts of relativity and quantum physics through the work of Bohr and Einstein is the basis for this upper level course for nonscience students. Along with their scientific philosophies, the political and moral theories of the scientists are studied. (CP)
Albert Einstein and LD: An Evaluation of the Evidence.
ERIC Educational Resources Information Center
Thomas, Marlin
2000-01-01
This article refutes claims that Albert Einstein had a learning disability and argues the claim derives its force not from evidence but from belief that the greatest among us suffer from some impairment and from desire to enhance the status of a marginalized group by including exceptional individuals. (Contains references.) (Author/CR)
Albert Einstein's Personal Papers: A Physics Teaching Resource.
ERIC Educational Resources Information Center
Derman, Samuel
2000-01-01
Presents the concept of using Einstein the man as a way of generating interest in the study of physics among students. Finds that it provides an instantly recognizable face for science, thus a gateway to the subject through the discussion of the man. (Author/CCM)
How Einstein Discovered "E[subscript 0] = mc[squared]"
ERIC Educational Resources Information Center
Hecht, Eugene
2012-01-01
This paper traces Einstein's discovery of "the equivalence of mass [m] and energy ["E[subscript 0]"]." He came to that splendid insight in 1905 while employed by the Bern Patent Office, at which time he was not an especially ardent reader of physics journals. How then did the young savant, working outside of academia in semi-isolation, realize…
Microlensing, Newton-Einstein gravity, and conformal gravity
NASA Astrophysics Data System (ADS)
Mannheim, Philip D.
1995-07-01
We discuss some implications of the current round of galactic dark matter searches for galactic rotation curve systematics and dynamics, and show that these new data do not invalidate the conformal gravity program of Mannheim and Kazanas which has been advanced as a candidate alternative to both the standard second order Newton-Einstein theory and the need for dark matter. .
Comments on Jacobson's "entanglement equilibrium and the Einstein equation"
NASA Astrophysics Data System (ADS)
Casini, Horacio; Galante, Damián A.; Myers, Robert C.
2016-03-01
Using holographic calculations, we examine a key assumption made in Jacobson's recent argument for deriving Einstein's equations from vacuum entanglement entropy. Our results involving relevant operators with low conformal dimensions seem to conflict with Jacobson's assumption. However, we discuss ways to circumvent this problem.
Productive Learning: Science, Art, and Einstein's Relativity in Educational Reform
ERIC Educational Resources Information Center
Glazek, Stanislaw D.; Sarason, Seymour B.
2006-01-01
Why do people, college-bound or even in college, stay away in droves from courses in science, especially physics? Why do people know so little about the significance of Einstein's contributions which require dramatic changes in how we understand ourselves, our world, and the entire universe? Why have educational reforms failed? In this book, two…
Einstein's Annalen Papers: The Complete Collection 1901 - 1922
NASA Astrophysics Data System (ADS)
Renn, Jürgen
2005-05-01
In 1905, Einstein's Annus Mirabilis, Albert Einstein made three discoveries concerning the foundations of nature which form the basis of his fame as a physicist. These revolutionary papers on the light-quantum hypothesis, Brownian motion, and special relativity, were published in the journal "Annalen der Physik". All three are now established as pillars of modern science and its applications in technology and are an indispensable part of the modern world. This volume presents some of the most significant original papers which Albert Einstein ever wrote. It includes the facsimiles of the three revolutionary papers of 1905. In addition it contains papers which show the consequences of the ground-breaking ideas of these seminal papers from E=mcÂ² to the quantum theory of specific heats. It also features Einstein's first exposition of his new general theory of relativity. Introducing the original German papers the science historians Jürgen Renn (MPI for the History of Science, Berlin), David C. Cassidy (Hofstra University, Hempstead), Michel Janssen (University of Minnesota), and Robert Rynasiewicz (John Hopkins University) complement and comment the collection with topical articles.
A Conceptual Derivation of Einstein's Postulates of Special Relativity.
ERIC Educational Resources Information Center
Bearden, Thomas E.
This document presents a discussion and conceptual derivation of Einstein's postulates of special relativity. The perceptron approach appears to be a fundamentally new manner of regarding physical phenomena and it is hoped that physicists will interest themselves in the concept. (Author)
Emergent Gravitational Dynamics in Bose-Einstein Condensates
Sindoni, Lorenzo; Liberati, Stefano; Girelli, Florian
2009-12-15
We discuss a toy model for an emergent non-relativistic gravitational theory. Within a certain class of Bose-Einstein condensates, it is possible to show that, in a suitable regime, a modified version of non-relativistic Newtonian gravity does effectively describes the low energy dynamics of the coupled system condensate/quasi-particles.
Does the Saenger gedanken experiment advance Einstein's special relativity theory?
NASA Astrophysics Data System (ADS)
Schmidt, Werner
1987-12-01
The basics of Einstein's theory of special relativity are reviewed, and the impact of the Saenger gedanken experiment on the theory is considered. The application of this experiment to the clock paradox is stressed. The relevance of special relativity on some current astrophysical problems is addressed.
Spinning fluids in the Einstein-Cartan theory
NASA Technical Reports Server (NTRS)
Ray, J. R.; Smalley, L. L.
1983-01-01
An Eulerian variational principle for a spinning fluid in the Einstein-Cartan metric-torsion theory is presented. The variational principle yields the complete set of field equations for the system. The symmetric energy-momentum tensor is a sum of a perfect-fluid term and a spin term.
Columbia/Einstein observations of extragalactic X-ray sources
NASA Technical Reports Server (NTRS)
Ku, W. H. M.
1979-01-01
Results are presented of the analysis of data from observations of extragalactic objects with the imaging proportional counter on board the Einstein Observatory. Surveys of normal galaxies, radio galaxies, active galaxies, quasars and BL Lacs, and clusters of galaxies were studied in order to improve the understanding of the origin of the Milky Way Galaxy.
Albert Einstein and his mentor Max Talmey. The seventh Charles B. Snyder Lecture.
Ravin, J G
1997-01-01
While he was a student at the Munich medical school, Max Talmey strongly influenced the education of Albert Einstein. Their association occurred during five years of Einstein's second decade. They lost contact for many years after each left Munich. Talmey emigrated to the United States and practiced medicine, mainly ophthalmology, in New York City. He made significant contributions to medicine, to the popularization of Einstein's work, and to the development of international languages. The relationship of Talmey and Einstein was rekindled when Einstein visited and later moved to the United States.
Theoretical studies of Bose-Einstein condensates
NASA Astrophysics Data System (ADS)
Das, Kunal Kashyap
This thesis is a theoretical study of Bose-Einstein Condensation (BEC) in harmonically-trapped, weakly-interacting dilute gases. The motivation for this study is the experimental realization of BEC in trapped alkali gases since 1995. The weak inter-particle interactions and diluteness of the gases allow for a fairly accurate mean-field treatment and justifies a discrete quasi-particle description as we use in this work. This thesis considers three specific topics in the rapidly growing field of BEC theory: (i) interference effects in BEC, (ii) interaction-induced energy shifts and damping of excitations of condensates and (iii) the properties of highly anisotropic condensates. The results are summarized here: i. We show that if two multiply occupied boson modes are in eigenstates of the Hermitian relative phase operator, then the visibility of fringes formed by the interference between the modes is necessarily less than unity. For large total occupation numbers the visibility V ≤ pi/4. States with definite relative phase and unit visibility do exist. They are related to coherent states and are not orthogonal (not eigenstates of a Hermitian phase operator). This visibility limitation may make it possible to investigate experimentally the physical role of the relative phase eigenstates in interference measurements on BEC. ii. We evaluate analytically the asymptotic energy shifts of the high energy Bogoliubov quasi-particle modes. In spherical geometry, those modes display a 1/ n dependence on their number of radial nodes n but only a weak dependence on their angular momenta l. We obtain similar results for cylindrical geometry. We derive an implicit equation for the widths or decay rates gamma of the modes from an assumption of exponential decay. We use the equation to do a detailed numerical study of the trends in the behavior of the widths as a function of temperature, energy, particle number and scattering lengths. In particular, we find that widths due to
What Is the Largest Einstein Radius in the Universe?
Oguri, Masamune; Blandford, Roger D.
2008-08-05
The Einstein radius plays a central role in lens studies as it characterizes the strength of gravitational lensing. In particular, the distribution of Einstein radii near the upper cutoff should probe the probability distribution of the largest mass concentrations in the universe. Adopting a triaxial halo model, we compute expected distributions of large Einstein radii. To assess the cosmic variance, we generate a number of Monte-Carlo realizations of all-sky catalogues of massive clusters. We find that the expected largest Einstein radius in the universe is sensitive to parameters characterizing the cosmological model, especially {sigma}{sub s}: for a source redshift of unity, they are 42{sub -7}{sup +9}, 35{sub -6}{sup +8}, and 54{sub -7}{sup +12} arcseconds (errors denote 1{sigma} cosmic variance), assuming best-fit cosmological parameters of the Wilkinson Microwave Anisotropy Probe five-year (WMAP5), three-year (WMAP3) and one-year (WMAP1) data, respectively. These values are broadly consistent with current observations given their incompleteness. The mass of the largest lens cluster can be as small as {approx} 10{sup 15} M{sub {circle_dot}}. For the same source redshift, we expect in all-sky {approx} 35 (WMAP5), {approx} 15 (WMAP3), and {approx} 150 (WMAP1) clusters that have Einstein radii larger than 2000. For a larger source redshift of 7, the largest Einstein radii grow approximately twice as large. While the values of the largest Einstein radii are almost unaffected by the level of the primordial non-Gaussianity currently of interest, the measurement of the abundance of moderately large lens clusters should probe non-Gaussianity competitively with cosmic microwave background experiments, but only if other cosmological parameters are well-measured. These semi-analytic predictions are based on a rather simple representation of clusters, and hence calibrating them with N-body simulations will help to improve the accuracy. We also find that these 'superlens
Ultraslow, stopped, and compressed light in Bose-Einstein condensates
NASA Astrophysics Data System (ADS)
Dutton, Zachary John
We present theoretical analysis and experimental results of methods to achieve and use ultraslow light (USL), stopped light, and compressed light in sodium Bose-Einstein condensates (BECs). We present applications of these methods to study and harness both the coherent and superfluid properties of BECs. A description of the propagation of probe and coupling laser fields in three-level Λ configuration atoms is presented in a semiclassical description. This formalism is used to derive how electromagnetically induced transparency (EIT) and USL arise. We present novel theoretical results on the effect a fourth level, and effects of nonlinearities associated with a strong probe. Experimental demonstration of ultraslow light is presented. A description which includes atomic motion in Bose-condensed samples of alkali atoms is developed in a mean field description and coupled Gross-Pitaevskii equations are derived. A numerical code which solves these equations is presented. An analytic and numerical analysis reveal the limits on ultraslow light and compressed light imposed by the external atomic dynamics. We then show that using USL and switching the coupling field off allows storage of the coherent probe pulse information (amplitude and phase) in the atomic fields. Switching the coupling beam back on writes the coherent information back onto the probe field. Experimental demonstration is presented. We present experimental data and theoretical analysis showing how stopping light in a BEC creates an atom laser with the highest reported phase space density flux to date. Alternatively, reviving the probe pulse after significant BEC dynamics can be used to process the information before it is written back onto the probe. Possible applications to quantum processing are discussed. We then present results on a light "roadblock", whereby blocking part of the coupling field spatially compresses probe pulses to sizes on the order of the condensate healing length. The compressed
Einstein*s witches* sabbath in Brussels: The legend and the facts
NASA Astrophysics Data System (ADS)
Lambert, Franklin J.
2015-09-01
This paper is about the first Solvay Council on Physics, its surprising origin and its far reaching consequences. In spite of the various accounts that have been given by several authors - they include historians of science, but also outstanding scientists, such as Leon Rosenfeld, Niels Bohr and Eduardo Amaldi - it appears that only limited attention was paid so far to the more singular aspects of this legendary meeting, and to the peculiar circumstances which led to its convening. This fact may be due to the restricted availability of relevant documents, many of which are located in different archives. It also reflects the rather abstract character of Ernest Solvay*s Institute of Physics - an Institute without a permanent staff, governed by geographically separated bodies: a scientific committee with a chairman in Haarlem, a secretary in Copenhagen and an administrative committee in Brussels. One of the purposes of the paper is to fill this gap by revisiting the course of events which led to Solvay*s invitation of June 1911. Another aim is to present a brief, yet balanced, account of the deliberations which took place in October-November 1911, by pointing at some elements that may be regarded as highlights of the Council, and by focusing on the contrasting aspects of its main results: the contrast between the Council*s disappointing conclusions on the one hand, and its positive consequences on the other hand. Special attention in this context is given to the unexpected concern about the validity of Planck*s law, expressed by Emil Warburg, and to the apparent contradictions in Einstein*s private reactions to the outcome of the Brussels meeting. The paper also aims at restoring the truth about some facts regarding the Solvay reports and their discussion, by revealing the discrepancies between the official account - the Gauthier-Villars volume "La théorie du rayonnement et les quanta", published in 1912, and the actual proceedings of the conference, based on notes
Spatially compact solutions and stabilization in Einstein-Yang-Mills-Higgs theories.
Forgács, Péter; Reuillon, Sébastien
2005-08-01
New solutions to the static, spherically symmetric Einstein-Yang-Mills-Higgs equations with the Higgs field in the triplet (doublet) representation are presented. They form continuous families parametrized by alpha = M(W)/M(Pl) [M(W) (M(Pl)) denoting the W boson (the Planck) mass]. The corresponding space-times are regular and have spatially compact sections. A particularly interesting class with the Yang-Mills amplitude being nodeless is exhibited and is shown to be linearly stable with respect to spherically symmetric perturbations. For some solutions with nodes of the Yang-Mills amplitude a new stabilization phenomenon is found, according to which their unstable modes disappear as alpha increases (for the triplet) or decreases (for the doublet).
Growth dynamics of a Bose-Einstein condensate in a dimple trap without cooling
Garrett, Michael C.; Davis, Matthew J.; Ratnapala, Adrian; Ooijen, Eikbert D. van; Vale, Christopher J.; Weegink, Kristian; Schnelle, Sebastian K.; Vainio, Otto; Heckenberg, Norman R.; Rubinsztein-Dunlop, Halina
2011-01-15
We study the formation of a Bose-Einstein condensate in a cigar-shaped three-dimensional harmonic trap, induced by the controlled addition of an attractive ''dimple'' potential along the weak axis. In this manner we are able to induce condensation without cooling due to a localized increase in the phase-space density. We perform a quantitative analysis of the thermodynamic transformation in both the sudden and adiabatic regimes for a range of dimple widths and depths. We find good agreement with equilibrium calculations based on self-consistent semiclassical Hartree-Fock theory describing the condensate and thermal cloud. We observe that there is an optimal dimple depth that results in a maximum in the condensate fraction. We also study the nonequilibrium dynamics of condensate formation in the sudden turn-on regime, finding good agreement for the observed time dependence of the condensate fraction with calculations based on quantum kinetic theory.
Winding-number dependence of Bose-Einstein condensates in a ring-shaped lattice
Jezek, D. M.; Cataldo, H. M.
2011-01-15
We study the winding-number dependence of the stationary states of a Bose-Einstein condensate in a ring-shaped lattice. The system is obtained by confining atoms in a toroidal trap with equally spaced radial barriers. We calculate the energy and angular momentum as functions of the winding number and the barrier height for two quite distinct particle numbers. In both cases we observe two clearly differentiated regimes. For low barriers, metastable vortex states are obtained up to a maximum winding number that depends on the particle number and barrier height. In this regime, the angular momentum and energy show, respectively, almost linear and quadratic dependences on the winding number. For large barrier heights, on the other hand, stationary states are obtained up to a maximum winding number that depends only on the number of lattice sites, whereas energy and angular momentum are shown to be sinusoidal functions of the winding number.
Visibility and stability of superstripes in a spin-orbit-coupled Bose-Einstein condensate
NASA Astrophysics Data System (ADS)
Martone, G. I.
2015-04-01
We consider a spin-1/2 Bose-Einstein condensate with equal Rashba and Dresselhaus spin-orbit coupling. After reviewing some relevant features of the quantum phases of the system, we present a short study on how their properties are changed by the presence of non-zero magnetic detunings and spin-asymmetric interactions. At small values of the Raman coupling and of the magnetic field the so-called stripe phase occurs, which displays both superfluidity and periodic density modulations, in analogy with supersolids. We finally review a recent proposal (Phys. Rev. A 90, 041604) to improve the visibility of the fringes, based on the space separation of the two spin components into a 2D bi-layer configuration and on the application of a π/2 Bragg pulse, and we show that this new configuration also yields a sizable increase of the stability of the stripe phase against magnetic fluctuations.
Nonlinear localized modes in dipolar Bose-Einstein condensates in two-dimensional optical lattices
NASA Astrophysics Data System (ADS)
Rojas-Rojas, Santiago; Naether, Uta; Delgado, Aldo; Vicencio, Rodrigo A.
2016-09-01
We analyze the existence and properties of discrete localized excitations in a Bose-Einstein condensate loaded into a periodic two-dimensional optical lattice, when a dipolar interaction between atoms is present. The dependence of the Number of Atoms (Norm) on the energy of solutions is studied, along with their stability. Two important features of the system are shown, namely, the absence of the Norm threshold required for localized solutions to exist in finite 2D systems, and the existence of regions in the parameter space where two fundamental solutions are simultaneously unstable. This feature enables mobility of localized solutions, which is an uncommon feature in 2D discrete nonlinear systems. With attractive dipolar interaction, a non-trivial behavior of the Norm dependence is obtained, which is well described by an analytical model.
Scalable Bose-Einstein-condensate Sagnac interferometer in a linear trap
Burke, J. H. T.; Sackett, C. A.
2009-12-15
We demonstrate a two-dimensional atom interferometer in a harmonic magnetic waveguide using a Bose-Einstein condensate. Such an interferometer could measure rotation using the Sagnac effect. Compared to free space interferometers, larger interactions times and enclosed areas can in principle be achieved, since the atoms are not in free fall. In this implementation, we induce the atoms to oscillate along one direction by displacing the trap center. We then split and recombine the atoms along an orthogonal direction using an off-resonant optical standing wave. We enclose a maximum effective area of 0.1 mm{sup 2} limited by fluctuations in the initial velocity and by the coherence time of the interferometer. We argue that this arrangement is scalable to enclose larger areas by increasing the coherence time and then making repeated loops.
Radiating black holes in Einstein-Yang-Mills theory and cosmic censorship
Ghosh, Sushant G.; Dadhich, Naresh
2010-08-15
Exact nonstatic spherically symmetric black-hole solutions of the higher dimensional Einstein-Yang-Mills equations for a null dust with Yang-Mills gauge charge are obtained by employing Wu-Yang ansatz, namely, HD-EYM Vaidya solution. It is interesting to note that gravitational contribution of Yang-Mills (YM) gauge charge for this ansatz is indeed opposite (attractive rather than repulsive) that of Maxwell charge. It turns out that the gravitational collapse of null dust with YM gauge charge admits strong curvature shell focusing naked singularities violating cosmic censorship. However, there is significant shrinkage of the initial data space for a naked singularity of the HD-Vaidya collapse due to presence of YM gauge charge. The effect of YM gauge charge on structure and location of the apparent and event horizons is also discussed.
Acoustic superradiance from an optical-superradiance-induced vortex in a Bose-Einstein condensate
NASA Astrophysics Data System (ADS)
Ghazanfari, Nader; Müstecaplıoǧlu, Özgür Esat
2014-04-01
We consider the scattering of an acoustic wave from a vortex induced by optical superradiance. The vortex is created by pumping a large amount of angular momentum with a Laguerre-Gaussian light beam in an atomic Bose-Einstein condensate. We derive the mean-field dynamical equations of the light-superfluid system, and obtain the equations governing the elementary excitation of the system, which result in a massless Klein-Gordon equation with source terms. This equation describes the propagation of the sound wave in an effective space-time. Employing a simplifying draining bathtub model for the vortex, we investigate the scattering of the acoustic wave in the vortex phase and obtain a condition for the acoustic superradiance. We conclude that Laguerre-Gaussian-beam-induced sudden transition from homogeneous to vortex state in the superfluid leads to a prominent observation of the acoustic superradiance.
Photonic Band Gap via Quantum Coherence in Vortex Lattices of Bose-Einstein Condensates
Muestecaplioglu, Oe.E.; Oktel, M.Oe.
2005-06-10
We investigate the optical response of an atomic Bose-Einstein condensate with a vortex lattice. We find that it is possible for the vortex lattice to act as a photonic crystal and create photonic band gaps, by enhancing the refractive index of the condensate via a quantum coherent scheme. If high enough index contrast between the vortex core and the atomic sample is achieved, a photonic band gap arises depending on the healing length and the lattice spacing. A wide range of experimentally accessible parameters are examined and band gaps in the visible region of the electromagnetic spectrum are found. We also show how directional band gaps can be used to directly measure the rotation frequency of the condensate.
On the Josephson effect in a Bose-Einstein condensate subject to a density-dependent gauge potential
NASA Astrophysics Data System (ADS)
Edmonds, M. J.; Valiente, M.; Öhberg, P.
2013-07-01
We investigate the coherent dynamics of a Bose-Einstein condensate in a double well, subject to a density-dependent gauge potential. Further, we derive the nonlinear Josephson equations that allow us to understand the many-body system in terms of a classical Hamiltonian that describes the motion of a nonrigid pendulum with an initial angular offset. Finally we analyse the phase-space trajectories of the system, and describe how the self-trapping is affected by the presence of an interacting gauge potential.
Guenaydin, M.; Sierra, G.; Townsend, P.K.
1985-01-01
In this talk we give a review of our work on the construction and classification of N = 2 Maxwell-Einstein Supergravity theories (MESGT), study of the underlying algebraical and geometrical structure of these theories, and their compact and non-compact gaugings. We begin by summarizing our construction of the N = 2 MESGT's in five dimensions and give a geometrical interpretation to various scalar dependent quantities in the Lagrangian, based on the constraiants implied by supersymmetry. This is followed by a complete classification of the N = 2 MESGT's whose target manifolds parametrized by the scalar fields are symmetric spaces. 39 refs.
Newton’s second law, radiation reaction and type II Einstein-Maxwell fields
NASA Astrophysics Data System (ADS)
Newman, Ezra T.
2011-12-01
Considering perturbations of the Reissner-Nordström metric while keeping the perturbations in the class of type II Einstein-Maxwell metrics, we perform a spherical harmonic expansion of all the variables up to the quadrupole term. This leads to rather surprising results. Referring to the source of the metric as a type II particle (analogous to referring to a Schwarzschild-Reissner-Nordström or Kerr-Newman particle), we see immediately that the Bondi momentum of the particle takes the classical form of mass times velocity plus an electromagnetic radiation reaction term, while the Bondi mass loss equation becomes the classical gravitational and electromagnetic (electric and magnetic) dipole and quadrupole radiation. The Bondi momentum loss equation turns into Newton’s second law of motion containing the Abraham-Lorentz-Dirac radiation reaction force plus a momentum recoil (rocket) force, while the reality condition on the Bondi mass aspect yields the conservation of angular momentum. Two things must be pointed out: (1) these results, (equations of motion, etc) take place, not in the spacetime of the type II metric but in an auxiliary space referred to as {H}-space, whose physical meaning is rather obscure and (2) this analysis of the type II field equations is a very special case of a similar analysis of the general asymptotically flat Einstein-Maxwell equations. Although the final results are similar (though not the same), the analysis uses different equations (specifically, the type II field equations) and is vastly simpler than the general case. Without a great deal of the technical structures needed in the general case, one can see rather easily where the basic results reside in the type II field equations.
NASA Astrophysics Data System (ADS)
Grundmann, Siegfried
Referring to the Straus-Herrmann correspondence, we deal only with one aspect of the ``political Einstein'': his attitude towards Marx, Engels, Lenin and Stalin (who were in the past sometimes called the ``classics of Marxism-Leninism''). Einstein revered Marx, but condemned Stalin as a criminal. He also resisted attempts to be misused by representatives of ``dialectic materialism''.
Einstein's osmotic equilibrium of colloidal suspensions in conservative force fields
NASA Astrophysics Data System (ADS)
Fu, Jinxin; Ou-Yang, H. Daniel
2014-09-01
Predicted by Einstein in his 1905 paper on Brownian motion, colloidal particles in suspension reach osmotic equilibrium under gravity. The idea was demonstrated by J.B. Perrin to win Nobel Prize in Physics in 1926. We show Einstein's equation for osmotic equilibrium can be applied to colloids in a conservative force field generated by optical gradient forces. We measure the osmotic equation of state of 100nm Polystyrene latex particles in the presence of KCl salt and PEG polymer. We also obtain the osmotic compressibility, which is important for determining colloidal stability and the internal chemical potential, which is useful for predicting the phase transition of colloidal systems. This generalization allows for the use of any conservative force fields for systems ranging from colloidal systems to macromolecular solutions.
Thermal spin fluctuations in spinor Bose-Einstein condensates
NASA Astrophysics Data System (ADS)
Melé-Messeguer, M.; Juliá-Díaz, B.; Polls, A.; Santos, L.
2013-03-01
We study the thermal activation of spin fluctuations in dynamically stable spinor Bose-Einstein condensates. We analyze the specific cases of a nondipolar spin-1 condensate in the state m=0, where thermal activation results from spin-changing collisions, and of a chromium condensate in the maximally stretched state m=-3, where thermal spin fluctuations are due to dipole-induced spin relaxation. In both cases, we show that the low energy associated to the spinor physics may be employed for thermometry purposes down to extremely low temperatures, typically impossible to measure in Bose-Einstein condensates with the usual thermometric techniques. Moreover, the peculiar dependence of the system's entropy with the applied Zeeman energy opens a possible route for adiabatic cooling.
Breakdown of Bose-Einstein Distribution in Photonic Crystals
Lo, Ping-Yuan; Xiong, Heng-Na; Zhang, Wei-Min
2015-01-01
In the last two decades, considerable advances have been made in the investigation of nano-photonics in photonic crystals. Previous theoretical investigations of photon dynamics were carried out at zero temperature. Here, we investigate micro/nano cavity photonics in photonic crystals at finite temperature. Due to photonic-band-gap-induced localized long-lived photon dynamics, we discover that cavity photons in photonic crystals do not obey Bose-Einstein statistical distribution. Within the photonic band gap and in the vicinity of the band edge, cavity photons combine the long-lived non-Markovain dynamics with thermal fluctuations together to form photon states that memorize the initial cavity state information. As a result, Bose-Einstein distribution is completely broken down in these regimes, even if the thermal energy is larger or much larger than the cavity detuning energy. In this investigation, a crossover phenomenon from equilibrium to nonequilibrium steady states is also revealed. PMID:25822135
Breakdown of Bose-Einstein distribution in photonic crystals.
Lo, Ping-Yuan; Xiong, Heng-Na; Zhang, Wei-Min
2015-01-01
In the last two decades, considerable advances have been made in the investigation of nano-photonics in photonic crystals. Previous theoretical investigations of photon dynamics were carried out at zero temperature. Here, we investigate micro/nano cavity photonics in photonic crystals at finite temperature. Due to photonic-band-gap-induced localized long-lived photon dynamics, we discover that cavity photons in photonic crystals do not obey Bose-Einstein statistical distribution. Within the photonic band gap and in the vicinity of the band edge, cavity photons combine the long-lived non-Markovain dynamics with thermal fluctuations together to form photon states that memorize the initial cavity state information. As a result, Bose-Einstein distribution is completely broken down in these regimes, even if the thermal energy is larger or much larger than the cavity detuning energy. In this investigation, a crossover phenomenon from equilibrium to nonequilibrium steady states is also revealed.
Entanglement entropy and mutual information in Bose-Einstein condensates
Ding Wenxin; Yang Kun
2009-07-15
In this paper we study the entanglement properties of free nonrelativistic Bose gases. At zero temperature, we calculate the bipartite block entanglement entropy of the system and find that it diverges logarithmically with the particle number in the subsystem. For finite temperatures, we study the mutual information between the two blocks. We first analytically study an infinite-range hopping model, then numerically study a set of long-range hopping models in one dimension that exhibit Bose-Einstein condensation. In both cases we find that a Bose-Einstein condensate, if present, makes a divergent contribution to the mutual information which is proportional to the logarithm of the number of particles in the condensate in the subsystem. The prefactor of the logarithmic divergent term is model dependent.
Einstein's theory of gravity and the problem of missing mass.
Ferreira, Pedro G; Starkman, Glenn D
2009-11-01
The observed matter in the universe accounts for just 5% of the observed gravity. A possible explanation is that Newton's and Einstein's theories of gravity fail where gravity is either weak or enhanced. The modified theory of Newtonian dynamics (MOND) reproduces, without dark matter, spiral-galaxy orbital motions and the relation between luminosity and rotation in galaxies, although not in clusters. Recent extensions of Einstein's theory are theoretically more complete. They inevitably include dark fields that seed structure growth, and they may explain recent weak lensing data. However, the presence of dark fields reduces calculability and comes at the expense of the original MOND premise, that the matter we see is the sole source of gravity. Observational tests of the relic radiation, weak lensing, and the growth of structure may distinguish modified gravity from dark matter.
Theory of cold atoms: Bose-Einstein statistics
NASA Astrophysics Data System (ADS)
Yukalov, V. I.
2016-06-01
This tutorial is the continuation of the previous tutorial part, published in (2013 Laser Phys. 23 062001), where the basic mathematical techniques required for an accurate description of cold atoms for both types of quantum statistics are expounded. In the present part, the specifics of the correct theoretical description of atoms obeying Bose-Einstein statistics are explained, including trapped Bose atoms. In the theory of systems exhibiting the phenomenon of Bose-Einstein condensation, there exists a number of delicate mathematical points, whose misunderstanding often results in principally wrong conclusions. This is why the consideration in the present tutorial is sufficiently detailed in order that the reader could clearly understand the underlying mathematics and would avoid confusions.