# Comment about quasi-isotropic solution of Einstein equations near the cosmological singularity

@article{Khalatnikov2002CommentAQ, title={Comment about quasi-isotropic solution of Einstein equations near the cosmological singularity}, author={Isaak M. Khalatnikov and Alexander Yu. Kamenshchik and Alexei A. Starobinsky}, journal={Classical and Quantum Gravity}, year={2002}, volume={19}, pages={3845-3849} }

For the case of arbitrary hydrodynamical matter, we generalize the quasi-isotropic solution of Einstein equations near the cosmological singularity, found by Lifshitz and Khalatnikov in 1960 for the case of the radiation-dominated universe. It is shown that this solution always exists, but dependence of terms in the quasi-isotropic expansion acquires a more complicated form.

## 33 Citations

### Quasi-isotropic solution of the Einstein equations near a cosmological singularity for a two-fluid cosmological model

- Physics
- 2003

The quasi-isotropic inhomogeneous solution of the Einstein equations near a cosmological singularity in the form of a series expansion in the synchronous system of reference, first found by Lifshitz…

### Quasi-isotropic solution of the Einstein equations near a cosmological singularity for a two-fluid cosmological model

- Physics
- 2003

The quasi-isotropic inhomogeneous solution of the Einstein equations near a cosmological singularity in the form of a series expansion in the synchronous system of reference, first found by Lifshitz…

### Quasi-Isotropic Expansion for a Two-Fluid Cosmological Model Containing Radiation and String Gas

- Physics, MathematicsJournal of Experimental and Theoretical Physics
- 2019

The quasi-isotropic expansion for a simple two-fluid cosmological model, including radiation and string gas is constructed. The first non-trivial order expressions for the metric coefficients, energy…

### A general sudden cosmological singularity

- Mathematics
- 2010

We construct an asymptotic series for a general solution of the Einstein equations near a sudden singularity. The solution is quasi isotropic and contains nine independent arbitrary functions of the…

### A general proof of the conservation of the curvature perturbation

- Physics, Mathematics
- 2005

Without invoking a perturbative expansion, we define the cosmological curvature perturbation, and consider its behaviour assuming that the universe is smooth over a sufficiently large comoving scale.…

### Self-consistent initial conditions for primordial black hole formation

- Mathematics
- 2012

For an arbitrarily strong, spherically symmetric super-horizon curvature perturbation, we present analytic solutions of the Einstein equations in terms of the asymptotic expansion over the ratio of…

### Study of the Quasi-isotropic Solution near the Cosmological Singularity in Presence of Bulk-Viscosity

- Physics
- 2007

We analyze the dynamical behavior of a quasi-isotropic Universe in the presence of a cosmological fluid endowed with bulk viscosity. We express the viscosity coefficient as a power-law of the fluid…

### Inhomogeneity implies accelerated expansion

- Physics
- 2014

The Einstein equations for an inhomogeneous irrotational dust universe are analyzed. A set of mild assumptions, all of which are shared by the standard…

### δ M formalism: a new approach to cosmological perturbation theory in anisotropic inflation

- Physics
- 2018

We study the evolution of the metric perturbations in a Bianchi background in the long-wavelength limit. By applying the gradient expansion to the equations of motion we exhibit a generalized…

## References

SHOWING 1-10 OF 24 REFERENCES

### A New Type of Isotropic Cosmological Models without Singularity - Phys. Lett. B91, 99 (1980)

- Physics
- 1980

### Growth or decay of cosmological inhomogeneities as a function of their equation of state.

- Physics, MathematicsPhysical review. D, Particles and fields
- 1994

This work expands Einstein's equations in the synchronous gauge in terms of a purely space-dependent, ``seed,'' metric and shows that the (nonlinear) solution accurately describes a universe inhomogeneous at scales larger than the Hubble radius.

### Long wavelength iteration of Einstein's equations near a spacetime singularity.

- PhysicsPhysical review. D, Particles and fields
- 1995

We clarify the links between a recently developped long wavelength iteration scheme of Einstein's equations, the Belinski Khalatnikov Lifchitz (BKL) general solution near a singularity and the…

### M theory observables for cosmological space-times

- Physics, Mathematics
- 2001

We discuss the construction of the analog of an S-matrix for space-times that begin with a Big-Bang and asymptote to an FRW universe with nonnegative cosmological constant. When the cosmological…

### Classical theory of fields

- Physics, Geology
- 1952

The principle of relativity Relativistic mechanics Electromagnetic fields Electromagnetic waves The propagation of light The field of moving charges Radiation of electromagnetic waves Particle in a…

### Particle Physics and Inflationary Cosmology

- Physics, EducationPhysics Today
- 1987

With the invention of unified theories of strong, weak, electromagnetic and gravitational interactions, elementaryparticle physics has entered a very interesting and unusual stage of its development.…

### Problems of relativistic cosmology

- Physics
- 1964

CONTENTS I. Features of cosmological solutions of the gravitational equations 495 1. Introduction 495 2. General solution with fictitious singularity 496 3. Anisotropic solution with singularity 500…

### STOCHASTIC DE SITTER (INFLATIONARY) STAGE IN THE EARLY UNIVERSE

- Physics
- 1986

The dynamics of a large-scale quasi-homogeneous scalar field producing the de Sitter (inflationary) stage in the early universe is strongly affected by small-scale quantum fluctuations of the same…

### Power-law inflation.

- EconomicsPhysical review. D, Particles and fields
- 1985

A simple inflationary model characterized by a scale factor which grows like Sapprox.t/sup p/, with p a constant greater than one, which is called power-law inflation (PLI), and considers the constraints on this model coming from the requirement of solving the horizon, flatness, ''good'' reheating, and ''convenient'' perturbation-spectrum problems.