The Quantum-Corrected Fermion Mode Function during Inflation

Understand

My project computed the one loop fermion self-energy for massless Dirac + Einstein in the presence of a locally de Sitter background.

• I employed dimensional regularization and obtain a fully renormalized result by absorbing all divergences with Bogliubov, Parasiuk, Hepp and Zimmermann (BPHZ) counterterms.
• An interesting technical aspect of my computation was the need for a noninvariant counterterm, owing to the breaking of de Sitter invariance by our gauge condition.
• I also solved the effective Dirac equation for massless fermions during inflation in the simplest gauge, including all one loop corrections from quantum gravity.