scholarly journals Exact general relativistic perfect fluid disks with halos

2003 ◽  
Vol 68 (8) ◽  
Author(s):  
Daniel Vogt ◽  
Patricio S. Letelier
Keyword(s):  
Perfect Fluid ◽  
General Relativistic ◽  
Fluid Disks

On the classical and quantum irrotational motions of a relativistic perfect fluid I. Classical theory

1985 ◽  
Vol 401 (1820) ◽  
pp. 53-66 ◽  
Keyword(s):  
Perfect Fluid ◽  
Vacuum State ◽  
Background Field ◽  
Field Configuration ◽  
Spontaneous Breaking ◽  
Sound Waves ◽  
Action Functional ◽  
Fluid Equation ◽  
Goldstone Bosons ◽  
General Relativistic

Some aspects of perfect-fluid general-relativistic hydrodynamics under the assumptions of irrotationality and isentropicity are analysed. A new derivation of the known fact that the Lagrangian for these fluids is just the pressure is given. Then we study the fluctuations around a given background field configuration, extracting a rule that connects the order at which a Taylor expansion of the action functional possibly stops with the fluid equation of state. From a classical invariance of the action we deduce the conserved Noether current. Because of the spontaneous breaking of such an invariance on the vacuum state Goldstone bosons arise, which turn out to be just phonons (quantized sound waves). Some useful results concerning the linear theory of sound waves are also given.

A NONSINGULAR PERFECT FLUID CLASSICAL LEPTON MODEL OF ARBITRARILY SMALL RADIUS

2013 ◽  
Vol 22 (14) ◽  
pp. 1350088 ◽  
Author(s):  
THOMAS E. KIESS
Keyword(s):  
Electric Field ◽  
Perfect Fluid ◽  
Small Radius ◽  
Spherically Symmetric ◽  
Model Based ◽  
Perfect Fluids ◽  
General Relativistic ◽  
Relativistic Models ◽  
Lepton Model

We exhibit a classical lepton model based on a perfect fluid that reproduces leptonic charges and masses in arbitrarily small volumes without metric singularities or pressure discontinuities. This solution is the first of this kind to our knowledge, because to date the only classical general relativistic models that have reproduced leptonic charges and masses in arbitrarily small volumes are based on imperfect (anisotopic) fluids or perfect fluids with electric field discontinuities. We use a Maxwell–Einstein exact metric for a spherically symmetric static perfect fluid in a region in which the pressure vanishes at a boundary, beyond which the metric is of the Reissner–Nordström form. This construction models lepton mass and charge in the limit as the boundary → 0.

scholarly journals Shear-free conditions of a Chaplygin-gas-dominated universe

2021 ◽  
pp. 2150192
Author(s):  
Amare Abebe ◽  
Mudhahir Al Ajmi ◽  
Maye Elmardi ◽  
Hemwati Nandan ◽  
Noor ul Sabah
Keyword(s):  
General Relativity ◽  
Perfect Fluid ◽  
Chaplygin Gas ◽  
Current Investigation ◽  
Free Condition ◽  
General Relativistic ◽  
Relativistic Framework ◽  
Fluid Spacetimes

In this work, we revisit the shear-free conjecture of general relativity and study the well-known shear-free condition in the context of the Chaplygin-gas cosmology. It had been shown in previous investigations that, in the general relativistic framework, the matter congruences of shear-free perfect fluid spacetimes should be either expansion-free or rotation-free. Our current investigation, however, indicates that a universe dominated by a Chaplygin-gas can allow a simultaneous expansion and rotation of the fluid provided that certain non-trivial conditions, which we derive and describe in what follows, are met. We also show that, in the appropriate limiting cases, our results reduce to the expected results of dust spacetimes which can only expand or rotate, but not both, at the same time.

scholarly journals Spacetimes with Pseudosymmetric Energy-momentum Tensor

2016 ◽  
Vol 26 (2) ◽  
pp. 121 ◽  
Author(s):  
Sahanous Mallick ◽  
Uday Chand De
Keyword(s):  
Perfect Fluid ◽  
Energy Momentum Tensor ◽  
Momentum Tensor ◽  
Conformally Flat ◽  
Flat Spacetime ◽  
General Relativistic

The object of the present paper is to introduce spacetimes with pseudosymmetricenergy-momentum tensor. In this paper at first we consider the relation \(R(X,Y)\cdot T=fQ(g,T)\), that is, the energy-momentumtensor \(T\) of type (0,2) is pseudosymmetric. It is shown that in a general relativistic spacetimeif the energy-momentum tensor is pseudosymmetric, then the spacetime is also Ricci pseudosymmetricand the converse is also true. Next we characterize the perfect fluid spacetimewith pseudosymmetric energy-momentum tensor. Finally, we consider conformally flat spacetime withpseudosymmetric energy-momentum tensor.

Standard covariant formulation for perfect-fluid dynamics

1988 ◽  
Vol 186 ◽  
pp. 1-24 ◽  
Author(s):  
B. Carter ◽  
B. Gaffet
Keyword(s):  
Perfect Fluid ◽  
Chemical Constituents ◽  
Standard Form ◽  
Space Time ◽  
Variation Principle ◽  
Covariant Formulation ◽  
Invariance Group ◽  
Dynamical Equations ◽  
General Relativistic ◽  
Derivatives Of

After a brief description of the Milne generalization of the Galilean invariance group for the space–time of Newtonian kinematics, it is shown how the generalized Eulerian dynamical equations for the motion of a multiconstituent perfect (nonconducting) fluid can be expressed in terms of interior products of current 4-vectors with exterior derivatives of the appropriate 4-momentum 1-forms (whose role is central in this approach) in a fully covariant standard form whose structure is identical in the Newtonian case to that of the corresponding equation for the case of (special or general) relativistic perfect fluid mechanics. In addition to space–time covariance, this standard form exhibits chemical covariance in the sense that it is manifestly invariant under redefinition of the number densities of the independent conserved chemical constituents in terms of linear combinations of each other. It is shown how, in the strictly conservative case when no chemical reactions occur, this standard form, can be used (via the construction of suitably generalized Clebsch potentials) for setting up an Eulerian (fixed-point) variation principle in a form that is simultaneously valid for both Newtonian and relativistic cases.

scholarly journals Exact relativistic static charged perfect fluid disks

2004 ◽  
Vol 70 (6) ◽  
Author(s):  
D. Vogt ◽  
P. S. Letelier
Keyword(s):  
Perfect Fluid ◽  
Fluid Disks

scholarly journals The Minimal Geometric Deformation Approach: A Brief Introduction

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
J. Ovalle ◽  
R. Casadio ◽  
A. Sotomayor
Keyword(s):  
Perfect Fluid ◽  
Brane World ◽  
Geometric Deformation ◽  
General Relativistic ◽  
Deformation Approach

We review the basic elements of the Minimal Geometric Deformation approach in detail. This method has been successfully used to generate brane-world configurations from general relativistic perfect fluid solutions.

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