Recognition: unknown
How long before the end of inflation were observable perturbations produced?
read the original abstract
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 standard cosmology which is around 60, with the expectation that the actual value will be up to 10 below this. We also note a special property of the $\lambda \phi^4$ model which reduces the uncertainties in that case and favours a higher value, giving a fairly definite prediction of 64 e-foldings for that model. We note an extreme (and highly implausible) situation where the number of e-foldings can be even higher, possibly up to 100, and discuss the shortcomings of quantifying inflation by e-foldings rather than by the change in $aH$. Finally, we discuss the impact of non-standard evolution between the end of inflation and the present, showing that again the expected number of e-foldings can be modified, and in some cases significantly increased.
This paper has not been read by Pith yet.
Forward citations
Cited by 5 Pith papers
-
Inflation and topology from the no-boundary state
The no-boundary wavefunction on the 3-torus, summed over SL(3,Z) geometries using GL(3) automorphic forms, favors large inflating universes with N ≳ 250 e-folds and induces torus-moduli corrections to the CMB spectrum.
-
Inflaton Regeneration via Scalar Couplings: Generic Models and the Higgs Portal
For monomial inflationary potentials with k≥4, the inflaton regenerates from the thermal bath after reheating because its amplitude-dependent mass vanishes asymptotically.
-
Inflation from a Weyl-flat null origin
Single-field inflation with ε(N) approaching a constant in (0,1) at early times forms an asymptotic universality class with a Weyl-flat null origin while producing ns and r values compatible with Planck data.
-
Planck 2018 results. X. Constraints on inflation
Updated Planck CMB measurements give ns = 0.9649 ± 0.0042, r < 0.056, confirm flatness at 0.4 percent, and show no evidence for scale-dependent features or non-slow-roll dynamics in the inflaton potential.
-
On Global Embedding of Assisted Fibre Inflation
Assisted multi-fibre inflation distributes the required field range across several moduli in global CY orientifolds, overcoming single-field Kähler cone obstructions to realize viable inflation.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.