"Theory of Particle Physics and Cosmology" Seminar

Typical field theories feature a kinetic term quadratic in field derivatives, like (∂φ)². Introducing a kinetic term that is a nonlinear function of (∂φ)² does not violate Lorentz covariance of the action (and in the case of gauge theories inherits their gauge invariance), making it a viable case to study. Such models were already investigated, for example k-inflation models by Armendáriz-Picón and Mukhanov. I describe some general properties of kinetically non-canonical theories, including challenges in quantizing them to make a quantum field theory (to my knowledge still an open problem). I focus on a scalar theory with a Dirac-Born-Infeld style kinetic term and analyse its behaviour in the early universe (during and after Inflation). I simulate the self-production of the particles of this field, with the intention of proposing them as a dark matter candidate.