Authors: Diego Chialva
Date: 12 Apr 2010
Abstract: We study the production, spectrum and detectability of gravitational waves in models of the early Universe where first order phase transitions occur during inflation. We consider all possible sources: bubble collisions, dynamics of the fluid, thermal fluctuations, turbulence,The final spectrum of the waves is strongly affected by the constraints deriving from the requirement of efficient inflation (small backreaction of the sources) and by the redshift between the time of emission and the exit from horizon. It results that models with a few phase transitions leave no detectable marks in the CMBR nor a gravitational background sufficient for detection by interferometers such as LIGO, LISA, DECIGO. When the number of phase transitions is instead large, the primordial gravitational waves can be observed both in the CMBR or with LISA (marginally) and especially DECIGO. It is also discussed the nucleosynthesis bound and the constraints it places on the parameters of the models.
© M. Vallisneri 2012 — last modified on 2010/01/29
Tantum in modicis, quantum in maximis