Fermion particle production in a periodic potential (Q1431729)

The authors study production of fermions by an oscillatory inflaton field i.e. fermion production in the early universe. On the one hand, they restudy the fermion particle production using methods already known in the literature, performing more in-depth analysis then it is usually done. On the other hand, generalizing the complex trajectory WKB method (CWKB) from the bosonic to the fermionic case, they restudy the fermion production from this point of view and carefully compare the results. In particular, almost identical results to that of Greene and Kofman are obtained. In addition, most of the results have been rechecked numerically using the Runge-Kutta method.