Renormalization of Quantum Fields in Curved Spacetime

2021

Quantum fields in curved spacetime undergo fluctuations that produce non-vanishing vacuum expectation values of the stress-energy tensor, i.e., energy can be generated due to the gravitational field. The same happens for other type of background fields like gauge or scalars. This effect plays an important role in the early Universe, in astrophysical compact objects, and in strong electromagnetic phenomena. However, the computation of the stress-energy tensor, among others, is a highly nontrivial issue. In particular, non-trivial divergences appear when computing expectation values of local observables. The objective of my thesis is to tackle this issue by studying regularization and renorma…