Sourced Spectra in Bouncing Cosmologies and their potential detection in Laser Interferometers

by Ido Ben-Dayan

at Particles and Fields Seminar

Mon, 17 Jun 2019, 14:00
Sacta-Rashi Building for Physics (54), room 207


Bouncing Cosmology is an alternative to the rather successful Inflationary paradigm. A period of slow contraction is followed by a Bounce and then the reheating of the Universe to the Hot Big Bang Cosmology. On top of solving the problems of the Hot Big Bang Cosmology, it is free of the Big Bang singularity. In both paradigms structure formation is a result of initial quantum fluctuations of the vacuum. A rather generic prediction of the bouncing models is a blue tilted gravitational waves spectrum, that is unobservable on CMB scales and possibly observable with Laser Interferometers (LI) such as LIGO and LISA. We show that if there is a coupling between the scalar field driving the contraction and a gauge field, then additional 'sourced fluctuations' are generated. The resulting spectrum is chiral, slightly blue and arbitrarily close to scale invariance. We discuss the predictions of the model with respect to CMB and LI. While the particular model fails, it serves as a proof of concept that Bouncing Cosmologies can yield an observable gravitational waves signal on both CMB and LI scales.

Created on 12-06-2019 by Citron, Zvi (zhcitron)
Updaded on 12-06-2019 by Citron, Zvi (zhcitron)