Rollercoaster cosmology

@article{DAmico2021RollercoasterC,
  title={Rollercoaster cosmology},
  author={Guido D’Amico and Nemanja Kaloper},
  journal={Journal of Cosmology and Astroparticle Physics},
  year={2021},
  volume={2021}
}
Does inflation have to happen all in one go? The answer is a resounding no! All cosmological problems can be solved by a sequence of short bursts of cosmic acceleration, interrupted by short epochs of decelerated expansion. The spectrum of perturbations will still match the CMB and LSS if the earliest stage of the last O(50)- O(60) efolds is at least O(15) efolds long. Other stages can be considerably shorter. But as long as they add up to O(50)- O(60) efolds and the stages of decelerated… Expand
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References

SHOWING 1-10 OF 160 REFERENCES
Just enough inflation: power spectrum modifications at large scales
We show that models of `just enough' inflation, where the slow-roll evolution lasted only $50-60$ e-foldings, feature modifications of the CMB power spectrum at large angular scales. We perform aExpand
Punctuated inflation and the low CMB multipoles
We investigate inflationary scenarios driven by a class of potentials which are similar in form to those that arise in certain minimal supersymmetric extensions of the standard model. We find thatExpand
How long before the end of inflation were observable perturbations produced
We reconsider the issue of the number of e-foldings before the end of inflation at which observable perturbations were generated. We determine a plausible upper limit on that number for the standardExpand
Primeval corrections to the CMB anisotropies
We show that deviations of the quantum state of the inflaton from the thermal vacuum of inflation may leave an imprint in the CMB anisotropies. The quantum dynamics of the inflaton in such a stateExpand
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 thatExpand
Power-law inflation.
TLDR
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. Expand
On the cosmological implications of the string Swampland
Abstract We study constraints imposed by two proposed string Swampland criteria on cosmology. These criteria involve an upper bound on the range traversed by scalar fields as well as a lower bound onExpand
H0 tension, swampland conjectures, and the epoch of fading dark matter
Motivated by the swampland dS conjecture, we consider a rolling scalar field as the source of dark energy. Furthermore, the swampland distance conjecture suggests that the rolling field will lead atExpand
Primordial tensor perturbation in double inflationary scenario with a break
We study the primordial tensor perturbation produced from the double inflationary scenario with an intermediate break stage. Because of the transitions, the power spectrum deviates from the vacuumExpand
Horizon ratio bound for inflationary fluctuations.
We demonstrate that the gravity wave background amplitude implies a robust upper bound on the wavelength-to-horizon ratio at the end of inflation: lambda/H(-1) less than or approximately equal e(60),Expand
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