DATA: 11032019
SEZIONE DI ROMA III The calculation of tunneling actions, that control the exponential
suppression of the decay of metastable phases (like the unstable
electroweak vacuum), can be reformulated as an elementary variational
problem in field space. This alternative approach circumvents the use
of bounces in Euclidean space by introducing an auxiliary function, a
tunneling potential Vt that connects smoothly the metastable and
stable phases of the field potential V. The tunneling action is
obtained as the integral in field space of an action density that is a
simple function of Vt and V and can be considered as a generalization
of the thinwall action to arbitrary potentials. This formalism
provides new handles for the theoretical understanding of different
features of vacuum decay, can be easily extended to include
gravitational effects in an elegant way and has a number of useful
applications that I will discuss.
