# Creating spatial flatness by combining string gas cosmology and power law inflation

@article{Kamali2020CreatingSF,
title={Creating spatial flatness by combining string gas cosmology and power law inflation},
author={Vahid Kamali and Robert Brandenberger},
journal={arXiv: High Energy Physics - Theory},
year={2020}
}
• Published 22 February 2020
• Physics
• arXiv: High Energy Physics - Theory
We show that it is possible to combine an early phase of String Gas Cosmology which can explain the origin of the observed structures on cosmological scales with a short later period of power law inflation which creates spatial flatness. The resulting model is consistent with the swampland criteria'' and the constraints coming from the {\it Trans-Planckian Censorship Conjecture}. Such a construction is not possible using only canonical slow-roll inflation, but it can emerge in the warm…
2 Citations

## Figures from this paper

String cosmology backgrounds from classical string geometry
• Physics
• 2021
We introduce a very early universe model based on the thermodynamics of a gas of closed strings in a background which is non-perturbative in $\alpha'$. Upon considering the fully $\alpha'$-corrected
Stochastic gravitational-wave background in quantum gravity
• Physics
• 2020
Among all cosmological quantum-gravity or quantum-gravity-inspired scenarios, only very few predict a blue-tilted primordial tensor spectrum. We explore five of them and check whether they can

## References

SHOWING 1-10 OF 56 REFERENCES
Inflation Free, Stringy Generation of Scale-Invariant Cosmological Fluctuations in D = 3 + 1 Dimensions
We propose an alternative scenario to cosmic inflation for producing the initial seeds of cosmic structures. The cosmological fluctuations are generated by thermal fluctuation of the energy density
Inflationary universe: A possible solution to the horizon and flatness problems
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
Non‐Standard Cosmological Models and The Trans‐Planckian Censorship Conjecture
The trans‐Planckian censorship conjecture (TCC) puts an upper bound on the life‐time of de Sitter spacetimes. It has immediate consequences for inflationary cosmology. In the standard paradigm, the
Tensor modes from a primordial Hagedorn phase of string cosmology.
• Physics
Physical review letters
• 2007
It is shown that a Hagedorn phase of string gas cosmology can provide a causal mechanism for generating a nearly scale-invariant spectrum of scalar metric fluctuations, without the need for an intervening period of de Sitter expansion, and the spectrum of tensor metric fluctuations is also nearly scale invariant.
String gas cosmology
• Physics
• 2006
A critical review and summary of string gas cosmology is presented. A pedagogical derivation of the effective action starting from string theory, emphasizing the necessary approximations that must be
Minimal warm inflation
• Physics
Journal of Cosmology and Astroparticle Physics
• 2020
Slow-roll inflation is a successful paradigm. However we find that even a small coupling of the inflaton to other light fields can dramatically alter the dynamics and predictions of inflation. As an
Warm brane inflation with an exponential potential: A consistent realization away from the swampland
• Physics
Physical Review D
• 2020
It has very recently been realized that coupling branes to higher dimensional quantum gravity theories and considering the consistency of what lives on the branes, one is able to understand whether
String gas cosmology and structure formation
• Physics
• 2007
It has recently been shown that a Hagedorn phase of string gas cosmology may provide a causal mechanism for generating a nearly scale-invariant spectrum of scalar metric fluctuations, without the
Producing a scale-invariant spectrum of perturbations in a Hagedorn phase of string cosmology.
• Physics
Physical review letters
• 2006
In this cosmological scenario, the early Hagedorn phase of string gas cosmology goes over smoothly into the radiation-dominated phase of standard cosmology, without having a period ofcosmological inflation.