Entropy of the microwave background radiation in the observable universe

@article{Piao2006EntropyOT,
  title={Entropy of the microwave background radiation in the observable universe},
  author={Yun-song Piao},
  journal={Physical Review D},
  year={2006},
  volume={74},
  pages={047301}
}
We show that the cosmological constant at late-time places a bound on the entropy of microwave background radiation deposited in the future event horizon of a given observer, $S\ensuremath{\le}{S}_{{\ensuremath{\Lambda}}_{0}}^{3/4}$. This bound is independent of the energy scale of reheating and the FRW evolution after reheating. We also discuss why the entropy of microwave background in our observable universe has its present value. 
5 Citations

A UNIFIED DARK ENERGY MODEL FROM A VANISHING SPEED OF SOUND WITH EMERGENT COSMOLOGICAL CONSTANT

The problem of the cosmic acceleration is here revisited by using the fact that the adiabatic speed of sound can be assumed to be negligible small. Within the context of general relativity, the total

The generalized second law in chameleon cosmology

In this paper, we investigate the validity of the generalized second law of thermodynamics in flat Friedmann–Lemaitre–Robertson–Walker chameleon cosmology where the boundary of the universe is

Accelerating cosmologies with nonlinear electrodynamics

In this paper, we consider the framework of nonlinear electrodynamics in locally rotationally symmetric (LRS) Bianchi-I universe model composed of magnetic fluid. It has been shown that an

Thermodynamic behavior of time-dependent wormholes in Palatini f(R) gravity

In the frame work of Palatini approach to modified f ( R ) theories of gravity, we attempt to investigate the thermodynamic behavior of time-dependent wormhole geometries. By considering an evolving

Validity of the Generalized Second Law of Thermodynamics in the Logamediate and Intermediate Scenarios of the Universe

In this work, we have investigated the validity of the generalized second law of thermodynamics in logamediate and intermediate scenarios of the universe bounded by the Hubble, apparent, particle and

References

SHOWING 1-10 OF 33 REFERENCES

Positive vacuum energy and the N-bound

We argue that the total observable entropy is bounded by the inverse of the cosmological constant. This holds for all space-times with a positive cosmological constant, including cosmologies

Cosmological Event Horizons, Thermodynamics, and Particle Creation

It is shown that the close connection between event horizons and thermodynamics which has been found in the case of black holes can be extended to cosmological models with a repulsive cosmological

Islands in the Λ-sea: An alternative cosmological model

We propose an alternative cosmological model in which our observable Universe is an island in a cosmological constant sea. Initially the Universe is filled with cosmological constant of the currently

Dark Matter and Dark Energy

I briefly review our current understanding of dark matter and dark energy. The first part of this paper focusses on issues pertaining to dark matter including observational evidence for its

The Cosmological Constant and Dark Energy

Physics invites the idea that space contains energy whose gravitational effect approximates that of Einstein's cosmological constant, Lambda: nowadays the concept is termed dark energy or

The Acceleration of the universe, a challenge for string theory

Recent astronomical observations indicate that the universe is acceler- ating. We argue that generic quintessence models that accomodate the present day acceleration tend to accelerate eternally. As

Disturbing Implications of a Cosmological Constant

In this paper we consider the implications of a cosmological constant for the evolution of the universe, under a set of assumptions motivated by the holographic and horizon complementarity

Classical treatment of island cosmology

Computing the perturbation spectrum in the recently proposed Island Cosmology remains an open problem. In this paper we present a classical computation of the perturbations generated in this scenario