12:00–1:00 pm ERC 401
Host: Anastasia Sokolenko
Moinul Rahat (University of Southampton) "Gravitational wave signatures of massive vector boson production during inflation"
In this talk I will focus on the gravitational wave imprints of massive vector boson production during inflation through their axionic coupling to the pseudoscalar inflaton. This coupling enables nonperturbative production of one of the transverse gauge modes, overcoming the exponential suppression inherent to any massive particle production in the inflationary era. Inverse decay of the produced gauge modes impacts the power spectrum of primordial scalar and tensor perturbations and induces substantial nongaussianity. Constraining the parameter space from various observational bounds, I will extrapolate the scalar and tensor power spectrum at smaller scales taking into account the strong backreaction effects from gauge modes in the context of the Starobinsky model of inflation. I will show that the overproduction of primordial black holes from large scalar perturbations is avoided, while observable gravitational wave signals at various ground- and space-based interferometers emerge.
Short bio: Moinul is currently a postdoctoral research fellow at University of Southampton. He received his PhD in Physics from University of Florida in 2022 working under the supervision of Pierre Ramond. He is interested in the interplay of early universe cosmology and BSM physics.
