Sourced fluctuations in the Early Universe

TYPEHigh Energy Physics Seminar
Speaker:Ido Ben Dayan
Organizer:shlomo razamat
Time:11:30 - 12:35
Location:Lidow Nathan Rosen (300)
Abstract:We calculate the gravitational waves (GW) spectrum produced in various Early Universe scenarios from gauge field sources, thus generalizing earlier inflationary calculations to bouncing cosmologies. We consider generic couplings between the gauge fields and the scalar field dominating the energy density of the Universe. Due to this coupling a sourced GW spectrum is generated. For certain coupling, the spectrum can be arbitrarily close to scale invariant (still slightly blue), that is distinguishable form the slightly red inflationary one. Hence, we have a model that predicts GW both at CMB scales and Laser Interferometer scales. I will further discuss work in progress of how to disentangle between the different paradigms. 

Last, if time permits I'll discuss some generalizations of the recently proposed clockwork scenario. The clockwork scenario provides a mechanism to generate small parameters in an effective theory, while all fundamental parameters at the UV scale are order unity. As such it allows a solution to various hierarchy problems in physics.