# Physical basis for the symmetries in the Friedmann–Robertson–Walker metric

@article{Melia2016PhysicalBF, title={Physical basis for the symmetries in the Friedmann–Robertson–Walker metric}, author={Fulvio Melia}, journal={Frontiers of Physics}, year={2016}, volume={11}, pages={1-7} }

Modern cosmological theory is based on the Friedmann–Robertson–Walker (FRW) metric. Often written in terms of co-moving coordinates, this well-known solution to Einstein’s equations owes its elegant and highly practical formulation to the cosmological principle and Weyl’s postulate, upon which it is founded. However, there is physics behind such symmetries, and not all of it has yet been recognized. In this paper, we derive the FRW metric coefficients from the general form of the spherically…

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## References

SHOWING 1-10 OF 42 REFERENCES

### The cosmic horizon

- Physics
- 2007

The cosmological principle, promoting the view that the Universe is homogeneous and isotropic, is embodied within the mathematical structure of the Robertson‐Walker (RW) metric. The equations derived…

### THE COSMOLOGICAL SPACETIME

- Physics
- 2009

We present here the transformations required to recast the Robertson–Walker metric and Friedmann–Robertson–Walker equations in terms of observer-dependent coordinates for several commonly assumed…

### The Rh=ct universe

- Physics
- 2011

The backbone of standard cosmology is the Friedmann-Robertson-Walker solution to Einstein's equations of general relativity (GR). In recent years, observations have largely confirmed many of the…

### RELATIVISTIC EQUATIONS FOR ADIABATIC, SPHERICALLY SYMMETRIC GRAVITATIONAL COLLAPSE

- Physics
- 1964

The Einstein equations for a spherically symmetrical distribution of matter are studied. The matter is described by the stress-energy tensor of an ideal fluid (heat flow and radiation are therefore…

### Hydrodynamic Calculations of General-Relativistic Collapse

- Physics
- 1966

The general-relativistic equations governing the motion of a large mass under the influence of its own gravitational field and its own pressure have been approximated by finite-difference equations.…

### On Continued Gravitational Contraction

- Physics
- 1939

When all thermonuclear sources of energy are exhausted a sufficiently heavy star will collapse. Unless fission due to rotation, the radiation of mass, or the blowing off of mass by radiation, reduce…

### Alcock-Paczynski Test with Model-independent BAO Data

- Physics
- 2015

Cosmological tests based on the statistical analysis of galaxy distributions usually depend on source evolution. An exception is the Alcock-Paczynski (AP) test, which is based on the changing ratio…

### Gravitation and Cosmology: Principles and Applications of the General Theory of Relativity

- Physics
- 1973

A leading physicist delves into relativity and experimental applications Gravitation and Cosmology: Principles and Applications of the General Theory of Relativity offers a Nobel laureate's…

### OBSERVATIONAL EVIDENCE FROM SUPERNOVAE FOR AN ACCELERATING UNIVERSE AND A COSMOLOGICAL CONSTANT

- Physics
- 1998

We present spectral and photometric observations of 10 Type Ia supernovae (SNe Ia) in the redshift range 0.16 " z " 0.62. The luminosity distances of these objects are determined by methods that…