# Does inflation provide natural initial conditions for the universe

@article{Carroll2005DoesIP, title={Does inflation provide natural initial conditions for the universe}, author={S. Carroll and Jennifer Chen}, journal={General Relativity and Gravitation}, year={2005}, volume={37}, pages={1671-1674} }

If our universe underwent inflation, its entropy during the inflationary phase was substantially lower than it is today. Because a low-entropy state is less likely to be chosen randomly than a high-entropy one, inflation is unlikely to arise through randomly-chosen initial conditions. To resolve this puzzle, we examine the notion of a natural state for the universe, and argue that it is a nearly-empty spacetime. If empty space has a small vacuum energy, however, inflation can begin…

## 44 Citations

### Symmetries in evolving space time from present to prior universes

- Mathematics
- 2005

We wish to demonstrate how the presence of a dynamic cosmological parameter, plus a model of the universe as a quantum computer can be combined to give us a picture of early universe inflationary…

### Cyclic Inflation

- Physics
- 2008

We present an inflationary model that is geodesically complete and does not suffer from the transplanckian problem. In most inflationary models, massless (conformal) scalar field fluctuations in a…

### Origin of the universe: A hint from Eddington-inspired Born-Infeld gravity

- Physics
- 2013

We study the ‘initial state’ of an anisotropic universe in Eddington-inspired Born-Infeld gravity filled with a scalar field, whose potential has various forms. With this purpose, the evolution of a…

### Evolution of entanglement entropy in the early universe

- Physics
- 2014

We investigate the entropy evolution in the early universe by computing the change of the entanglement entropy in Freedmann-Robertson-Walker quantum cosmology in the presence of particle horizon. The…

### Evolution of entanglement entropy in the early universe

- Physics
- 2014

We investigate the entropy evolution in the early universe by computing the change of the entanglement entropy in Freedmann-Robertson-Walker quantum cosmology in the presence of particle horizon. The…

### Arrows of time and the beginning of the universe

- Mathematics
- 2013

I examine two cosmological scenarios in which the thermodynamic arrow of time points in opposite directions in the asymptotic past and future. The first scenario, suggested by Aguirre and Gratton,…

### Can thermal input from a prior universe account for relic graviton production

- Physics
- 2006

Primer for how intense graviton production can be obtained in the first 10 to the minus 43 seconds of cosmological inflation. In addition several cosmological models which appear to have conclusions…

### Can thermal input from a prior universe account for relic graviton production?

- Physics
- 2006

The author presents how answering Sean Carroll’s supposition of a pre inflation state of low temperature-low entropy pre inflation state as given in 2005 provides a bridge between two models with…

### Can a Parabolic Evolution of the Entropy of the Universe Provide the Foundation for the Second Law of Thermodynamics

- Physics
- 2012

In this thesis, we want to address the foundations of the second law of thermodynamics. More explicit, we want to discuss a cosmological model featuring a parabolic-like evolution of the entropy of…

### Is the Hypothesis About a Low Entropy Initial State of the Universe Necessary for Explaining the Arrow of Time

- Physics
- 2016

According to statistical mechanics, micro-states of an isolated physical system (say, a gas in a box) at time t0 in a given macro-state of less-than-maximal entropy typically evolve in such a way…

## References

SHOWING 1-10 OF 63 REFERENCES

### Spontaneous inflation and the origin of the arrow of time

- Physics
- 2004

We suggest that spontaneous eternal inflation can provide a natural explanation for the thermodynamic arrow of time, and discuss the underlying assumptions and consequences of this view. In the…

### Can the universe afford inflation

- Economics
- 2004

Cosmic inflation is envisioned as the 'most likely' start for the observed universe. To give substance to this claim, a framework is needed in which inflation can compete with other scenarios and the…

### Inflation and time asymmetry in the Universe

- PhysicsNature
- 1983

The recently proposed inflationary Universe scenario1–4 explains several of the mysteries of modern cosmology. I argue here that it also provides a natural explanation for the origin of time…

### Causality and cosmic inflation

- Physics
- 1999

In the context of inflationary models with a pre-inflationary stage, in which the Einstein equations are obeyed, the null energy condition is satisfied, and spacetime topology is trivial, we argue…

### Recycling universe

- Physics
- 1997

If the effective cosmological constant is non-zero, our observable universe may enter a stage of exponential expansion. In such case, regions of it may tunnel back to the false vacuum of an inflaton…

### Inflation without a beginning: A Null boundary proposal

- Physics
- 2003

We develop our recent suggestion that inflation may be made past eternal, so that there is no initial cosmological singularity or "beginning of time". Inflation with multiple vacua generically…

### Essay: An Alternative to Inflation

- Physics
- 2002

Inflationary models are generally credited with explaining the large scale homogeneity, isotropy, and flatness of our universe as well as accounting for the origin of structure (i.e., the deviations…

### Birth of inflationary universes

- Physics
- 1983

A cosmological model is proposed in which the Universe is created by quantum tunneling from ''nothing'' into a de Sitter space. The tunneling is described by a de Sitter-- p Hawking--Moss instanton.…

### Inflationary universe: A possible solution to the horizon and flatness problems

- Physics
- 1981

The standard model of hot big-bang cosmology requires initial conditions which are problematic in two ways: (1) The early universe is assumed to be highly homogeneous, in spite of the fact that…

### Science and Ultimate Reality: Cosmic inflation and the arrow of time

- Physics
- 2004

Cosmic inflation claims to make the initial conditions of the standard big bang "generic". But Boltzmann taught us that the thermodynamic arrow of time arises from very non-generic ("low entropy")…