# Towards a Physical Interpretation for the Stephani Universes

@article{Sussman1999TowardsAP, title={Towards a Physical Interpretation for the Stephani Universes}, author={Roberto A. Sussman}, journal={General Relativity and Gravitation}, year={1999}, volume={32}, pages={1527-1557} }

A physically reasonable interpretation is provided for the perfect fluid, spherically symmetric, conformally flat "Stephani Universes". The free parameters of this class of exact solutions are determined so that the ideal gas relation p = nkBT is identically fulfilled, while the full equation of state of a classical monatomic ideal gas and a matter-radiation mixture holds up to a good approximation in a near dust, matter dominated regime. Only the models having spacelike slices with positive…

## 15 Citations

### Angular sizes in spherically symmetric Stephani cosmological models

- Physics
- 2006

Spherically symmetric Stephani cosmological models are considered in the context of angular sizes of compact as well as expanding objects percepted by an observer placed at the symmetry centre. We…

### Local thermal equilibrium and ideal gas Stephani universes

- Physics
- 2005

The Stephani universes that can be interpreted as an ideal gas evolving in local thermal equilibrium are determined. Five classes of thermodynamic schemes are admissible, which give rise to five…

### Undermining the cosmological principle: almost isotropic observations in inhomogeneous cosmologies

- Physics
- 2000

We challenge the widely held belief that the cosmological principle is an obvious consequence of the observed isotropy of the cosmic microwave background radiation (CMB), combined with the Copernican…

### Accelerated Expansion of the Universe in the Model with Nonuniform Pressure

- PhysicsThe Astrophysical Journal
- 2019

We present the particular case of the Stephani solution for shear-free perfect fluid with uniform energy density and nonuniform pressure. Such models appeared as possible alternative to the…

### Dark side of the universe in the Stephani cosmology

- Physics
- 2014

We investigate the late time acceleration of the universe in the context of the Stephani model. This solution generalizes those of Friedmann–Lemaitre–Robertson–Walker (FLRW) in such a way that the…

### Geodesic Structure of the Accelerated Stephani Universe

- PhysicsSymmetry
- 2021

This work investigates the main scenarios of the test particle and photon motion in the spherically symmetric Stephani cosmological model with an accelerated expansion and shows that a comoving observer sees an appropriate picture.

### The quantum Stephani Universe in the vicinity of the symmetry center

- Physics
- 2008

We study a class of spherically symmetric Stephani cosmological models in the presence of a self-interacting scalar field in both classical and quantum domains. We discuss the construction of…

### Relativistic compressibility conditions

- PhysicsPhysical Review D
- 2020

The constraints imposed by the relativistic compressibility hypothesis on the square of the speed of sound in a medium are obtained. This result allows to obtain purely hydrodynamic conditions for…

### Non-homogeneity-driven universe acceleration

- Physics
- 2001

A class of spherically symmetric Stephani cosmological models is examined in the context of evolution type. It is assumed that the equation of state at the symmetry centre of the models is barotropic…

### Accelerated expansion of the universe from the perspective of inhomogeneous cosmology

- Physics, Mathematics
- 2020

We present a special case of the Stephani solution with spherical symmetry while considering different values of spatial curvature. We investigate the dynamics of the universe evolution in our model,…

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