Joint cosmology seminar at Tufts online:

Tuesday, October 8, 2024, 2:30 pm
{\large\sf Zoom link will be distributed to joint cosmology seminar mailing list. See\\
https://cosmos.phy.tufts.edu/mailman/listinfo/cosmology-seminar to join.\\}
Tufts University

Weyl Fermion Creation by Cosmological Gravitational Wave Background at 1-loop

Azadeh Maleknejad
Kings College London

Abstract:

Weyl fermions, when minimally coupled to Einstein's gravity, cannot be produced purely gravitationally in an expanding universe. However, this picture changes at the gravitational 1-loop level in the presence of cosmic perturbations, leading to a new and unavoidable mechanism for gravitational particle production. In this talk, I will explore the theory and rich phenomenological implications of this new particle production mechanism. Notably, if Weyl fermions acquire mass and assuming a realistic--and potentially detectable--gravitational wave background, this mechanism could explain the abundance of dark matter in the Universe.