 1e−25  1e−20  1e−15  1e−10  1e−05  1  100000  0  50  100  150  200  250  300  350  400 2*M$_{S}$ M$_{S}$ M /2 S M /4 S M$_{S}$ 2*M$_{S}$ M /2 S M /4 S Grav Wave Energy Gauge Field Energy Time FIG. 19: Different colors show how the gravitational wave energy and gauge field energy grow for different values of the tachyonic mass. FIG. 20: Snap-shots of iso-surface of the energy density for gauge field, gravity waves, tachyon and the inflaton (from left-to-right) at a particular instant of time, t = 300. The plots are taken from [727]. On particular realistic example of preheating [124, 608] can be illustrated by the SM Higgs inflation [86]. After inflation the Higgs field evolves in time, h = h ( χ ( t )), see Eq. (215), so the effective masses of the fermions and of the gauge bosons also obtain time dependence. where θ$_{W}$ is the Weinberg angle θ$_{W}$ = tan − $^{1}$( g$_{1}$/g$_{2}$ ), and y$_{f}$ , g$_{1}$ and g$_{2}$ are the Yukawa and the U (1)$_{Y}$ and SU (2)$_{L}$ couplings, respectively. The time dependent Higgs VEV spontaneously breaks the gauge symmetry, and give masses to W and Z gauge bosons masses. The relevant 190 8. SM Higgs preheating m$_{W}$ = m$_{Z}$ cos θ$_{W}$ = 1 2 g$_{2}$h ( χ ( t )) , m$_{f}$ = 1 2 y$_{f}$ h ( χ ( t )) , (410)