Tunneling in real time

Marzo 25, 2019
De 3:00pm hasta 4:00pm

IFT Seminar Room/Red Room

Theoretical Physics, general interest
Speaker: 
Carlos Tamarit
Institution: 
Munich Tech. U.
Location&Place: 

IFT Seminar Room/Red Room

Abstract: 
Tunneling calculations in quantum mechanics and quantum field theory are usually performed in Euclidean time by means of semiclassical expansions of the path integral.
An understanding of how the complete calculation can be defined in real time, and whether one can recover the Euclidean result, was so far missing: although the existence of complex saddle points in real time has been already pointed out, it was not yet clear how the integration of fluctuations might be carried out and related to its Euclidean counterpart. We show that the result obtained for an arbitrary rotation of the time contour matches the Euclidean one. We also provide an interpretation of vacuum decay in terms of the optical theorem, and point out that the effective potential at the false vacuum can be related to the normalization of the corresponding state.