Quantum vacuum effects imply that particles can be created from vacuum due to the influence of an external time dependent perturbation, such as an intense short-pulse laser field. It is now understood that the detailed (possibly sub-cycle) temporal profile of the external pulse has a significant effect on the particle yield, due to quantum interference. Such particle rates are computed at asymptotic late times, after the external pulse has passed. In this talk I propose a new concept of super-adiabatic particle number that probes also intermediate times, raising the surprising possibility of defining particle number even during the creation process itself. The technical input is a remarkable result, due to Dingle and Berry, about universal behaviour of high orders of the adiabatic expansion. I also briefly mention applications to cosmological particle production in expanding and contracting cosmologies.

Seminarraum HI-Jena, Fröbelstieg 3
Datum (Start der Veranstaltung)