## Citations with the tag: EINSTEIN field equations

### Results 101 - 150

- Conformal transformations and viscous fluids in general relativity.

Carot, J.; Mas, Ll. // Journal of Mathematical Physics; Sep86, Vol. 27 Issue 9, p2336It is shown that viscous fluid solutions can be obtained by performing conformal transformations of vacuum solutions of Einsteinï¿½s 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, p708A 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, p4248Presents 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, p5117Studies 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, p5131Studies 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, p5143Shows 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;...

- General solutions of Einsteinï¿½s spherically symmetric gravitational equations with junction conditions.

Das, A.; DeBenedictis, A.; Tariq, N. // Journal of Mathematical Physics; Dec2003, Vol. 44 Issue 12, p5637Einsteinï¿½s spherically symmetric interior gravitational equations are investigated. Following Syngeï¿½s 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, p21A 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...

- Towards the classification of static vacuum spacetimes with negative cosmological constant.

Chrusciel, Piotr T.; Simon, Walter // Journal of Mathematical Physics; Apr2001, Vol. 42 Issue 4We 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.

- Einsteinâ€“Maxwell equations and the groups of homothetic motion.

Faridi, Abbas M. // Journal of Mathematical Physics; Feb90, Vol. 31 Issue 2, p401The Einsteinâ€“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, p371The 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, p2683Exact solutions of Einsteinâ€™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 Einsteinâ€™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, p1334The Einsteinâ€™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, p1322This paper extends the earlier discussion of the types of energy-momentum tensors TÎ¼Î½ 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 TÎ¼Î½ are discussed. For each of...

- Exact self-gravitating disks and rings: A solitonic approach.

Letelier, P. S.; Oliveira, S. R. // Journal of Mathematical Physics; Jan1987, Vol. 28 Issue 1, p165The Belinskyâ€“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, p2110Exact, 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 Einsteinâ€“Maxwell equations.

Torres del Castillo, G. F. // Journal of Mathematical Physics; Sep89, Vol. 30 Issue 9, p2114The 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, p4117The 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, p4053Gives 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, p4025Examines 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, p5792Reports 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, p3035Derives 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, p4962Describes 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.

- The HH equation in arbitrary canonical coordinates.

Torres del Castillo, G. F. // Journal of Mathematical Physics; Jan1985, Vol. 26 Issue 1, p152Extending 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, p465The explicit expression of a Petrov type G solution to the Einsteinâ€“Maxwell equations is given. This new solution is endowed with eight arbitrary parameters; mass, Newmanâ€“Untiâ€“Tamburino (NUT) parameter, angular momentum, acceleration, electric and magnetic charges, and...

- Exact solutions of an algebraically extended Kaluzaâ€“Klein theory.

Mann, R. B. // Journal of Mathematical Physics; Sep85, Vol. 26 Issue 9, p2308The four-dimensional field equations in an algebraically extended Kaluzaâ€“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, p262Four 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, p1076Classes of inhomogeneous perfect fluid solutions can be obtained by requiring that the associated Weyl tensor corresponds to a nonflat vacuum solution of Einsteinâ€™s field equations. It is shown how one derives from this assumption useful information on the Newmanâ€“Penrose variables....

- On solution spaces of massless field equations with arbitrary spin.

Heidenreich, W. // Journal of Mathematical Physics; Aug86, Vol. 27 Issue 8, p2154The solution spaces of massless field equations [Laplacian_variant] Î¨=0, with Î¨ being a tensor, a (multi)spinor, or a Raritaâ€“Schwinger field, are studied. They carry indecomposable representations of the PoincarÃ© 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, p2111The 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, p2105An analogy between source-free, asymptotically Taubâ€“NUT magnetic monopole solutions to Einsteinâ€™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...

- Einsteinâ€“Maxwell equations and the conformal Ricci collineations.

Faridi, Abbas M. // Journal of Mathematical Physics; Jun87, Vol. 28 Issue 6, p1370The Einsteinâ€“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, p449An analytic solution to Einsteinâ€™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...

- Symmetries of Einsteinâ€™s field equations with a perfect fluid source as examples of Lieâ€“BÃ¤cklund symmetries.

Stephani, H. // Journal of Mathematical Physics; Jul88, Vol. 29 Issue 7, p1650The framework of Lieâ€“BÃ¤cklund (or generalized) symmetries is used to give a unifying view of some of the known symmetries of Einsteinâ€™s field equations for the vacuum or perfect fluid case (with a Î¼=p or a Î¼+3p=0 equation of state). These symmetries occur if space-time...

- Spherically symmetric solutions in higher dimensions.

Krori, K. D.; Borgohain, P.; Das, Kanika // Journal of Mathematical Physics; Oct89, Vol. 30 Issue 10, p2315An exact general solution of Einsteinâ€™s equations for spherically symmetric distribution of a perfect fluid in N dimensions is presented from which the whole class of spherically symmetric solutions may be obtained. As examples, some particular solutions obtainable from a general solution...

- Involutive systems of differential equations: Einsteinâ€™s strength versus Cartanâ€™s degrÃ© dâ€™arbitraire.

Sué, Michael // Journal of Mathematical Physics; Feb91, Vol. 32 Issue 2, p392Three new theorems relating Einsteinâ€™s notions of â€˜â€˜strengthâ€™â€™ and â€˜â€˜compatibilityâ€™â€™ to the field of the initial-value problem are presented. These theorems result (i) in a first proof of Matthewsâ€™ conjectures concerning this...

- Colliding gravitational waves with Killingâ€“Cauchy horizons.

Li, Wei; Hauser, Isidore; Ernst, Frederick J. // Journal of Mathematical Physics; Apr91, Vol. 32 Issue 4, p1025A large family of solutions that were constructed earlier [J. Math. Phys. 32, 723 (1991)] is shown to exhibit Killingâ€“Cauchy horizons when one of the parameters, n, is set equal to 3, 1, -1, or -3.

- On the gravitational interaction of plane symmetric clouds of null dust.

Tsoubelis, Dimitri; Wang, Anzhong // Journal of Mathematical Physics; Apr91, Vol. 32 Issue 4, p1017Plane symmetric solutions of the Einstein field equations are considered, solutions that represent the collision of oppositely moving clouds of initially unidentified massless particlesâ€”clouds of â€˜â€˜null dust.â€™â€™ In terms of specific examples it is shown that the...

- Nondiagonal double seed solutions and double soliton solution family of the Einstein equations.

Gao, Ya-Jun; Zhong, Zai-Zhe // Journal of Mathematical Physics; Jan1992, Vol. 33 Issue 1, p278By using the double inverse scattering method, the problem of how to find new soliton solutions of the stationary axisymmetric vacuum field equation is studied. It is found that, for some kinds of seed solutions, the scattering wave functions can be directly obtained. Some examples of...

- Conformal symmetry inheritance with cosmological constant.

Tariq, N.; Tupper, B. O. J. // Journal of Mathematical Physics; Dec92, Vol. 33 Issue 12, p4002A study is made of space-times satisfying the Einstein field equations with a nonzero cosmological constant and admitting a conformal Killing vector (CKV), Î¾a, which is such that the Lie derivative of the energy-momentum tensor in the direction of Î¾a is zero. This condition is necessary,...

- Metric of two arbitrary Kerrâ€“Newman sources located on the symmetry axis.

Manko, V. S.; Martín, J.; Ruiz, E. // Journal of Mathematical Physics; Dec94, Vol. 35 Issue 12, p6644An exact asymptotically flat axisymmetric solution of the Einsteinâ€“Maxwell equations representing the exterior field of two arbitrary Kerrâ€“Newman masses located on the symmetry axis is constructed in explicit form. In a particular case, when the solution describes two identical...

- A family of cosmological solutions in higher-dimensional Einstein gravity.

Coley, Alan A.; McManus, Des J. // Journal of Mathematical Physics; Jan1995, Vol. 36 Issue 1, p335Presents a two-parameter family of solutions to Einstein's vacuum field equations in six dimensions. Natural extension of a one-parameter family of five-dimensional vacuum solutions found by Ponce de Leon; Background on the problem of embedding pseudo-Riemannian manifolds in flat spaces of...

- Mass spectra from field equations. II. The electromagnetic contribution.

Good Jr., R.H. // Journal of Mathematical Physics; Feb95, Vol. 36 Issue 2, p707Extends a method for finding a mass spectrum from a given field equation, to include the self-electromagnetic effect on the rest mass. Field Lagrangian; Field Hamiltonian and the basic equation; Special assumptions about the vector potential.

- Space-time defects.

Letelier, Patricio S.; Wang, Anzhong // Journal of Mathematical Physics; Jun95, Vol. 36 Issue 6, p3023Discusses the use of the theory of distributions in Riemannian spaces to obtain exact solutions to the Einstein equations for space-times. Generation of metrics that represent space-time defects; Presentation of considerations for cylindrically, plane and axially symmetric thin shells.

- Tuning the properties of matter to any chosen dynamical behavior in cosmological models...

Magli, Giulio // Journal of Mathematical Physics; Jun95, Vol. 36 Issue 6, p3054Focuses on the construction of the Einstein field equations governing Bianchi type I space-times in elastic media. Relativistic theory of elasticity; Characterization of the physical properties of the elastic medium; Energy density for the elastic field.

- The interaction of outgoing and ingoing spherically symmetric null fluids.

Holvorcem, Paulo R.; Letelier, Patricio S.; Anzhong Wang // Journal of Mathematical Physics; Jul95, Vol. 36 Issue 7, p3663Examines the reduction of the Einstein field equations coupled to two oppositely directed null fluids for spherically symmetric space-time to an autonomous system of three ordinary differential equations using similarity methods. Backscattering of an initially outgoing null fluid shell in a...

- Exact solutions of the Einstein equations with sources from linearized solutions.

del Castillo, G.F. Torres // Journal of Mathematical Physics; Sep96, Vol. 37 Issue 9, p4584Discusses the exact solutions of the Einstein-Maxwell equations with sources from linearized solutions. Generalization of the Xanthopoulos theorem; Analogous solutions of the Einstein-Weyl equations.

- Stationary Bianchi type II perfect fluid models.

Nilsson, Ulf S.; Uggla, Claes // Journal of Mathematical Physics; May97, Vol. 38 Issue 5, p2611Studies Einstein's field equations for stationary Bianchi type II models with perfect fluid source. Rewriting of the field equations as a system of autonomous first-order differential equations; Dimensionless variables introduced for which the reduced phase space is compact.

- Form invariance of differential equations in general relativity.

Chimento, Luis P. // Journal of Mathematical Physics; May97, Vol. 38 Issue 5, p2565Studies the reduction of Einstein equations for several matter sources in Robertson-Walker and Bianchi I type metrics to a kind of second-order nonlinear ordinary differential equation. Generalized statistical mechanics for values; Linearization of the equation; Application of form invariance...