Analytic Approximations for Fermionic Preheating
This study investigates how non-thermal fermions are produced during preheating when a scalar field oscillates in a quartic potential. The analysis shows that for small coupling parameters, fermion production is dominated by specific resonance peaks in momentum rather than the continuous bulk region. Analytic approximations provide scaling laws for total number density based on the coupling strength, and mass constraints are derived if these fermions constitute dark matter.