Abstract
The cosmic history before the BBN is highly determined by the physics that operates beyond the Standard Model (BSM) of particle physics and it is poorly constrained observationally. Ongoing and future precision measurements of the CMB observables can provide us with significant information about the pre-BBN era and hence possibly test the cosmological predictions of different BSM scenarios. Supersymmetry is a particularly motivated BSM theory and it is often the case that different superymmetry breaking schemes require different cosmic histories with specific reheating temperatures or low entropy production in order to be cosmologically viable. In this paper we quantify the effects of the possible alternative cosmic histories on the ns and r CMB observables assuming a generic non-thermal stage after cosmic inflation. We analyze TeV and especially multi-TeV super-symmetry breaking schemes assuming the neutralino and gravitino dark matter scenarios. We complement our analysis considering the Starobinsky R2 inflation model to exemplify the improved CMB predictions that a unified description of the early universe cosmic evolution yields. Our analysis underlines the importance of the CMB precision measurements that can be viewed, to some extend, as complementary to the laboratory experimental searches for supersymmetry or other BSM theories.
Highlights
Scenarios often imply a different cosmic evolution in order to satisfy the BBN predictions and the observed dark matter abundance ΩDMh2 = 0.12 [1, 2]
The cosmic history before the BBN is highly determined by the physics that operates beyond the Standard Model (BSM) of particle physics and it is poorly constrained observationally
In most of the inflationary models, a precise measurement of the spectral index ns(N∗) and tensor-to-scalar ratio r(N∗) value accounts for an indirect measure of the reheating temperature of the universe [4,5,6,7,8,9,10,11,12,13] and one could in principle examine the cosmology of theories beyond the Standard Model of particle physics as well as non-trivial extensions of the Einstein gravity [14]
Summary
When the scalar X coherently oscillates about the minimum of a effectively quadratic potential it is wX = 0 In such a case, at the cosmic time tdXom Γ−X1 the energy density of X is larger than that of the plasma and the universe enters a scalar dominated era that dilutes any pre-existing abundances of the relativistic degrees of freedom at the time of the X decay. The maximum value of the ∆NX ∼ 15 is achieved when Nrh → 0 and Nrad → 0 This case corresponds to the maximum dilution scenario where the X field oscillations dominate the energy density of the universe right after the end of high scale inflation until the onset of BBN. Plugging in the thermal reference value n(sth) that a given inflation model yields, the expression (2.20) returns the shift in the spectral index due to a pre-BBN dilution of.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
