Speaker
Description
We introduce a new approach to renormalize physical quantities in curved space-time
by adiabatic subtraction. We use a comoving infrared cut-off in defining the adiabatic counterpart of
the physical quantity under consideration. We show how this infrared cut-off should be used to
obtain a completely well-defined renormalization scheme and how it is fundamental to avoid unphysical
divergences that can be generated by a pathological behavior of the adiabatic subtraction extended
to the infrared domain. The infrared cut-off appears as a new degree of freedom introduced in the theory
and its actual value has to be consistently fixed by a physical prescription. As an example, we show
how such degree of freedom can be set to obtain the correct value of the conformal anomaly in the
symptomatic case of an inflationary model with gauge fields coupled to a pseudo-scalar inflaton.
