Citations with the tag: EINSTEIN field equations

Results 101 - 150

  • A Noncommutative Generalization of the Free-Field Yang�Mills Equations.
    McCabe, Gordon // International Journal of Theoretical Physics; Feb2006, Vol. 45 Issue 2, p350 

    The purpose of this paper is to propose a noncommutative generalization of a gauge connection and the free-field Yang�Mills equations. The paper draws upon the techniques proposed by Heller et al. for the noncommutative generalization of the Einstein field equations.

  • Reduction of the Einstein equations in 2+1 dimensions to a Hamiltonian system over Teichm�ller space.
    Moncrief, Vincent // Journal of Mathematical Physics; Dec89, Vol. 30 Issue 12, p2907 

    In this paper the ADM (Arnowitt, Deser, and Misner) reduction of Einstein�s equations for three-dimensional ��space-times�� defined on manifolds of the form S�R, where S is a compact orientable surface, is discussed. When the genus g of S is greater than unity it is...

  • Null geodesics in the gravitational field of a rotating, radiating body.
    Hadley, R. H.; Mallett, R. L. // Journal of Mathematical Physics; Mar1993, Vol. 34 Issue 3, p1007 

    A solution of the Einstein field equations for a rotating radiating body was presented by Carmeli and Kaye in 1977 [Ann. Phys. 103, 97 (1977)]. Their paper presented a new line element along with the corresponding energy-momentum tensor for the radiation field. The Newman�Penrose formalism...

  • On a class of invariant coframe operators with application to gravity.
    Itin, Yakov; Kaniel, Shmuel // Journal of Mathematical Physics; Sep2000, Vol. 41 Issue 9 

    Let a differential 4D-manifold with a smooth coframe field be given. Consider the operators on it that are linear in the second order derivatives and quadratic in the first order derivatives of the coframe, both with coefficients that depend on the coframe variables. The article exhibits the...

  • A black-box self-consistent field convergence algorithm: One step closer.
    Kudin, Konstantin N.; Scuseria, Gustavo E.; Cance`s, Eric // Journal of Chemical Physics; 5/15/2002, Vol. 116 Issue 19, p8255 

    A direct inversion iterative subspace version of the relaxed constrained algorithm is found to be a very powerful convergence acceleration technique for the solution of the self-consistent field equations found in the Hartree-Fock method and Kohn-Sham-based density functional theory (KS-DFT)....

  • Wavelike solutions to the Einstein equations coupled to neutrino and gauge fields.
    Torres del Castillo, G. F. // Journal of Mathematical Physics; Nov86, Vol. 27 Issue 11, p2756 

    Starting from the plane-wave metric, solutions to the Einstein field equations coupled to a Weyl neutrino field and to a Yang�Mills field are found. These solutions can be superposed to yield a solution with both sources if the direct interaction between them is neglected. A solution to the...

  • Effects of the shear viscosity on the character of cosmological evolution.
    Huang, Wung-Hong // Journal of Mathematical Physics; Mar1990, Vol. 31 Issue 3, p659 

    Bianchi type I cosmological models are studied that contain a stiff fluid with a shear viscosity that is a power function of the energy density, such as ?=aen. These models are analyzed by describing the cosmological evolutions as the trajectories in the phase plane of Hubble functions. The...

  • Exact model for a relativistic star.
    Tikekar, Ramesh // Journal of Mathematical Physics; Oct90, Vol. 31 Issue 10, p2454 

    Assuming that the physical three-space in a relativistic superdense star has the geometry of a three-spheroid, a static spherically symmetric model based on an analytic closed-form solution of Einstein�s field equations is presented. Assuming the density of the order of 2�1014 g cm-3,...

  • Shear-free perfect fluids in general relativity II. Aligned, Petrov type III space-times.
    Carminati, J. // Journal of Mathematical Physics; Oct90, Vol. 31 Issue 10, p2434 

    Petrov type III, shear-free, perfect fluid solutions of the Einstein field equations, with a barotropic equation of state p=p(w) satisfying w+p[not_identically_equal_to_(3_lines_with_slashthrough)]0, are investigated. It is shown that if the acceleration of the fluid is orthogonal to the...

  • Static Bondi energy in the teleparallel equivalent of general relativity.
    Maluf, J.W.; da Rocha-Neto, J.F. // Journal of Mathematical Physics; Mar1999, Vol. 40 Issue 3, p1490 

    Focuses on Bondi's radiating metric in the context of the teleparallel equivalent of general relativity (TEGR). Description of the asymptotic form of a radiating solution of Einstein's equations; Expression of Bondi's solution in asymptotically spherical three plus one coordinates; Lagrangian...

  • Conformal transformations and viscous fluids in general relativity.
    Carot, J.; Mas, Ll. // Journal of Mathematical Physics; Sep86, Vol. 27 Issue 9, p2336 

    It is shown that viscous fluid solutions can be obtained by performing conformal transformations of vacuum solutions of Einstein�s field equations. The solutions obtained by such a procedure can be matched, under certain conditions, to their respective original vacuum metrics.

  • Stationary axisymmetric interior metric for a charged perfect fluid source.
    Garc�a D., Alberto // Journal of Mathematical Physics; Mar1991, Vol. 32 Issue 3, p708 

    A stationary axisymmetric type-D solution of the Einstein equations coupled with an electromagnetic field and a rigidly rotating perfect fluid distribution of finite dimensions is presented. For vanishing fluid parameters, it reduces to the Carter [A] metric, which contains among others the...

  • Tomimatsu-Sato electrovacuum cosmic string solutions for delta=2 interacting with gravitational...
    Papadopoulos, Demetrios B.; Xanthopoulos, Basilis C. // Journal of Mathematical Physics; Aug95, Vol. 36 Issue 8, p4248 

    Presents a cylindrically symmetric solution for Einstein-Maxwell electro-vacuum equations. Provision of the mechanism for galaxy formation and gravitational focusing; Control of the degrees of freedom of the gravitational field (GF); Representation of relative strength of the electromagnetism...

  • Linearization stability of the Einstein equation for Robertson-Walker models. I.
    Bruna, Lluis; Girbau, Joan // Journal of Mathematical Physics; Oct99, Vol. 40 Issue 10, p5117 

    Studies the linearization stability of the Einstein equation in the presence of matter. Robertson-Walker model considered; Stability of the equation in the case of the spacelike hypersurface having a constant curvature; Origin of the linearization stability of empty space Einstein equation.

  • Linearization stability of the Einstein equation for Robertson-Walker models. II.
    Bruna, Lluis; Girbau, Joan // Journal of Mathematical Physics; Oct99, Vol. 40 Issue 10, p5131 

    Studies the linearization stability of the Einstein equation for Robertson-Walker models of curvature. Instability of the Einstein equation at the initial metric when the curvature is positive; Notation used in the study; Expressions needed in the proof of the theorem.

  • Well-posed forms of the 3+1 conformally-decomposed Einstein equations.
    Frittelli, Simonetta; Reula, Oscar A. // Journal of Mathematical Physics; Oct99, Vol. 40 Issue 10, p5143 

    Shows that well-posed, conformally-decomposed formulations of the 3+1 Einstein equations can be obtained by densitizing the lapse and by combining the constraints with the evolution equations. Computation of the characteristics structure; Constraint propagation of the well-posed formulations;...

  • Local twistors and the conformal field equations.
    Frauendiener, Jo�rg; Sparling, George A. J. // Journal of Mathematical Physics; Jan2000, Vol. 41 Issue 1 

    In this paper we establish the connection between Friedrich's conformal field equations and the conformally invariant formalism of local twistors. � 2000 American Institute of Physics.

  • General solutions of Einstein�s spherically symmetric gravitational equations with junction conditions.
    Das, A.; DeBenedictis, A.; Tariq, N. // Journal of Mathematical Physics; Dec2003, Vol. 44 Issue 12, p5637 

    Einstein�s spherically symmetric interior gravitational equations are investigated. Following Synge�s procedure, the most general solution of the equations is furnished in case T[sub 1][sup 1] and T[sub 4][sup 4] are prescribed. The existence of a total mass function, M(r,t), is...

  • Waves in solids with vectorial microstructure.
    Pastrone, Franco // Proceedings of the Estonian Academy of Sciences, Physics, Mathem; Mar2003, Vol. 52 Issue 1, p21 

    A general model of solids with vectorial microstructures is introduced. Field equations are obtained via a variational principle, with natural boundary conditions. It is proved that scalar unidimensional bodies and Cosserat solids are included in this model. Waves and stability problems are...

  • Gravoelectric dual of the Kerr solution.
    Dadhich, Naresh; Patel, L. K.; Patel, L.K. // Journal of Mathematical Physics; Feb2000, Vol. 41 Issue 2 

    By decomposing the Riemann curvature into electric and magnetic parts, we define the gravoelectric duality transformation by interchange of active and passive electric parts which amounts to interchange of the Ricci and Einstein tensors. It turns out that the vacuum equation is duality...

  • A big-bang cylindrically symmetric radiation universe.
    Davidson, W. // Journal of Mathematical Physics;  

    A new nonstationary cylindrically symmetric solution to Einstein’s equations is given for a perfect fluid. The solution has a time singularity (t=0) at which the pressure p and density μ are equal to +∞ throughout the radial coordinate range 0≤r<∞, but for t>0 the model...

  • Towards the classification of static vacuum spacetimes with negative cosmological constant.
    Chrusciel, Piotr T.; Simon, Walter // Journal of Mathematical Physics; Apr2001, Vol. 42 Issue 4 

    We present a systematic study of static solutions of the vacuum Einstein equations with negative cosmological constant which asymptotically approach the generalized Kottler ("Schwarzschild-anti-de Sitter") solution, within (mainly) a conformal framework. We show connectedness of conformal...

  • Theory of high-frequency guided waves in a plasma-loaded waveguide.
    Ganguli, A.; Akhtar, M.K.; Tarey, R.D. // Physics of Plasmas;  

    Describes the theory of high-frequency guided waves in a plasma-loaded waveguide. Effects of finite electron/ion temperatures on wave dispersion; Discussion on the equations for the plasma axis; Use of vacuum solutions for field equations.

  • The diffusivity-mobility ratio in nonparabolic materials.
    Ghatak, K. P.; Mondal, M. // Journal of Applied Physics;  

    Presents a study that examined the Einstein relation for the diffusivity mobility ratio of the carriers in several materials and bismuth by formulating the expressions in accordance with the models used. Theoretical background; Results and discussion.

  • Einstein–Maxwell equations and the groups of homothetic motion.
    Faridi, Abbas M. // Journal of Mathematical Physics; Feb90, Vol. 31 Issue 2, p401 

    The Einstein–Maxwell field equations for a source-free, non-null electromagnetic field are studied under the assumption of admitting a nontrivial homothetic conformal motion, generating a homothetic bivector which is also non-null. It is shown that a space-time, whether vacuum or not,...

  • Inflation in a spatially closed anisotropic universe.
    Ponce de León, J. // Journal of Mathematical Physics; Feb90, Vol. 31 Issue 2, p371 

    The effects of shear on the occurrence of inflation are studied on the basis of a simple model for a spatially closed universe which enters an inflationary era. It is assumed that the universe enters a vacuum-dominated phase in an abrupt transition that occurs everywhere at the same time. The...

  • The gravitational field of plane symmetric thick domain walls.
    Goetz, Guenter // Journal of Mathematical Physics; Nov90, Vol. 31 Issue 11, p2683 

    Exact solutions of Einstein’s equations for a scalar field with a potential V([uppercase_phi_synonym]) =V0 cos2(1-n) ([uppercase_phi_synonym]/f(n)) (0

  • Exact solutions of Einstein’s equations for space-time with local rotational symmetry in which the Dirac equation separates.
    Jing, Jiliang // Journal of Mathematical Physics; May91, Vol. 32 Issue 5, p1334 

    The Einstein’s equations for space-time with local rotational symmetry in which the Dirac equation separates are studied. All possible solutions are exhibited for a fluid with negative pressure. Other solutions correspond to radiation and a stiff fluid.

  • Interaction of null dust clouds fronted by plane impulsive gravitational waves. II.
    Taub, A. H. // Journal of Mathematical Physics; May91, Vol. 32 Issue 5, p1322 

    This paper extends the earlier discussion of the types of energy-momentum tensors Tμν that can exist in the region of interaction of two colliding plane impulsive gravitational waves, each followed by a null dust cloud. Two additional types of tensors Tμν are discussed. For each of...

  • Singularity-free static fluid spheres in general relativity.
    Orlyansky, Oleg Yu. // Journal of Mathematical Physics; Oct97, Vol. 38 Issue 10, p5301 

    Focuses on singularity-free static fluid spheres in general relativity. Einstein equations; Modification of the known methods of obtaining exact spherically symmetric solutions.

  • Exact self-gravitating disks and rings: A solitonic approach.
    Letelier, P. S.; Oliveira, S. R. // Journal of Mathematical Physics; Jan1987, Vol. 28 Issue 1, p165 

    The Belinsky–Zakharov version of the inverse scattering method is used to generate a large class of solutions to the vacuum Einstein equations representing uniformly accelerating and rotating disks and rings. The solutions studied are generated from a simple class of static disks and...

  • Nonstatic charged spheres admitting a conformal Killing vector.
    Rago, H. // Journal of Mathematical Physics; Sep89, Vol. 30 Issue 9, p2110 

    Exact, nonstatic, spherically symmetric solutions of the Einstein-Maxwell equations are found for self-gravitating charged spheres under the assumption of the existence of a conformal Killing vector. Solutions are matched to the Reissner-Nordstrom metric and it is found that as a consequence of...

  • Spin-3/2 perturbations of algebraically special solutions of the Einstein–Maxwell equations.
    Torres del Castillo, G. F. // Journal of Mathematical Physics; Sep89, Vol. 30 Issue 9, p2114 

    The equations for the spin-3/2 perturbations of the solutions of the Einstein-Maxwell equations given by the linearized O (2) extended supergravity are considered. It is shown that for each geodetic and shear-free principal null direction of the background electromagnetic field there exists a...

  • Qualitative analysis of diagonal Bianchi type V imperfect fluid cosmological models.
    Coley, A. A.; Hoogen, R. J. van den // Journal of Mathematical Physics; Aug94, Vol. 35 Issue 8, p4117 

    The Einstein field equations for diagonal Bianchi type V imperfect fluid cosmological models with both viscosity and heat conduction are set up as an autonomous system of differential equations using dimensionless variables and a set of dimensionless equations of state. Models with and without a...

  • Perturbations of solutions of the Einstein-Maxwell equations with a null background...
    del Castillo, G.F. Torres // Journal of Mathematical Physics; Aug96, Vol. 37 Issue 8, p4053 

    Gives a derivation of the expressions for the complete perturbations of the solutions of the Einstein-Maxwell equations with a null background electromagnetic field in terms of two complex scalar potentials using Wald's method and the Newman-Penrose notation. Decoupled equations and scalar...

  • Conditions on the stability of the external space solutions in a higher-dimensional quadratic...
    Kleidis, K.; Varvoglis, H.; Papadopoulos, D.B. // Journal of Mathematical Physics; Aug96, Vol. 37 Issue 8, p4025 

    Examines the conditions under which stable colutions to the field equations for the scale function of the external space may be derived in the context of a five-dimensional quadratic theory of gravity using Lyapounov's direct method. Explicit form of the field equations for a quadratic theory...

  • Axially symmetric metrics from Laplace's seed by inverse scattering method.
    Chaudhuri, S.; Das, K.C. // Journal of Mathematical Physics; Nov97, Vol. 38 Issue 11, p5792 

    Reports on two-soliton solutions of axially symmetric Einstein field equations using two different Laplace's solutions as seed. Reduction of the derived stationary solutions; Surface geometry of the metrics; Evidence that the solutions generated from the Inverse Scattering Method of...

  • Large amplitude gravitational waves.
    Ali, G.; Hunter, John K. // Journal of Mathematical Physics; Jun99, Vol. 40 Issue 6, p3035 

    Derives an asymptotic solution of the Einstein field equations which describes the propagation of a thin, large amplitude gravitational wave into a curved space-time. Same form of the resulting equations as the colliding plane wave equations without one of the usual constraint equations; Exact...

  • Scalar field inhomogeneous cosmologies.
    Feinstein, A.; Ibanez, J.; Labraga, P. // Journal of Mathematical Physics; Sep95, Vol. 36 Issue 9, p4962 

    Describes exact solutions for the Einstein field equations corresponding to inhomogeneous cosmologies with an exponential-potential scalar field. Discussion the properties related to generalized inflation and asymptotic behavior of the models.

  • Comments on the use of the Einstein equation for transport diffusion: Application to argon in AlPO[sub 4]-5.
    Tepper, H. L.; Briels, W. J. // Journal of Chemical Physics; 6/1/2002, Vol. 116 Issue 21, p9464 

    Two methods to calculate corrected collective diffusion coefficients in zeolites are compared. The meaning of the center-of-mass coordinate that occurs in the usual Einstein expression for the corrected diffusivity is discussed. The use of unfolded particle trajectories in the expression is...

  • The HH equation in arbitrary canonical coordinates.
    Torres del Castillo, G. F. // Journal of Mathematical Physics; Jan1985, Vol. 26 Issue 1, p152 

    Extending previous results, the equation which determines the algebraically special solutions to the Einstein vacuum field equations is given in an arbitrary system of coordinates adapted to the congruence of totally null two-dimensional surfaces that these space-times possess. The action of the...

  • The gravitational field of a charged, magnetized, accelerating, and rotating mass.
    García Díaz, Alberto; Bretón Baez, Nora // Journal of Mathematical Physics; Mar1985, Vol. 26 Issue 3, p465 

    The explicit expression of a Petrov type G solution to the Einstein–Maxwell equations is given. This new solution is endowed with eight arbitrary parameters; mass, Newman–Unti–Tamburino (NUT) parameter, angular momentum, acceleration, electric and magnetic charges, and...

  • Exact solutions of an algebraically extended Kaluza–Klein theory.
    Mann, R. B. // Journal of Mathematical Physics; Sep85, Vol. 26 Issue 9, p2308 

    The four-dimensional field equations in an algebraically extended Kaluza–Klein theory are solved in the static spherically symmetric case. Eight distinct classes of solutions are found, some of which are free of singularities in both the metric and the electromagnetic field.

  • Fluid sources for Bianchi I and III space-times.
    Bayin, Selçuk Ş.; Krisch, J. P. // Journal of Mathematical Physics; Jan1986, Vol. 27 Issue 1, p262 

    Four analytic solutions to the Einstein field equations are presented. The solutions are parametrized to have either Bianchi I or Bianchi III symmetry. The associated fluid parameters are given and some of them are discussed in detail.

  • Conformally Ricci-flat perfect fluids.
    Van den Bergh, N. // Journal of Mathematical Physics; Apr86, Vol. 27 Issue 4, p1076 

    Classes of inhomogeneous perfect fluid solutions can be obtained by requiring that the associated Weyl tensor corresponds to a nonflat vacuum solution of Einstein’s field equations. It is shown how one derives from this assumption useful information on the Newman–Penrose variables....

  • On solution spaces of massless field equations with arbitrary spin.
    Heidenreich, W. // Journal of Mathematical Physics; Aug86, Vol. 27 Issue 8, p2154 

    The solution spaces of massless field equations [Laplacian_variant] Ψ=0, with Ψ being a tensor, a (multi)spinor, or a Rarita–Schwinger field, are studied. They carry indecomposable representations of the Poincaré group whose invariant subspaces are determined. There exist...

  • Total energy momentum in general relativity.
    Ó Murchadha, Niall // Journal of Mathematical Physics; Aug86, Vol. 27 Issue 8, p2111 

    The energy momentum of any asymptotically flat vacuum solution to the Einstein equations is a well-defined, conserved, Lorentz-covariant, timelike, future-pointing vector. The only requirement is that one be given asymptotically flat initial data that satisfy very weak continuity and falloff...

  • Dual mass, H-spaces, self-dual gauge connections, and nonlinear gravitons with topological origin.
    Magnon, Anne // Journal of Mathematical Physics; Aug86, Vol. 27 Issue 8, p2105 

    An analogy between source-free, asymptotically Taub–NUT magnetic monopole solutions to Einstein’s equation and self-(anti-self-) dual gauge connections is displayed, which finds its origin in the first Chern class of these space-times. A definition of asymptotic graviton modes is...

  • Einstein–Maxwell equations and the conformal Ricci collineations.
    Faridi, Abbas M. // Journal of Mathematical Physics; Jun87, Vol. 28 Issue 6, p1370 

    The Einstein–Maxwell field equations for non-null electromagnetic fields are studied under the assumption of admitting a conformal Ricci collineation. It is shown that a non-null electromagnetic field does not admit any conformal Ricci collineation, unless the generators of the symmetry...

  • Bianchi type VI0 space-times with perfect fluid source.
    Ram, Shri // Journal of Mathematical Physics; Feb88, Vol. 29 Issue 2, p449 

    An analytic solution to Einstein’s field equations is presented for the Bianchi type VI0 class of models. The energy-momentum tensor is of the perfect fluid type. The solution corresponds to a locally rotationally symmetric and expanding cosmological universe which would give an...

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