Speaker
Description
It has been shown that the longitudinal mode of a massive vector boson can be p\
roduced by inflationary fluctuations and account for the dark matter content of\
the Universe. In this work we examine the possibility of instead producing the\
transverse mode via the coupling ϕFF̃ between the inflaton and the vector field\
strength. Such a coupling leads to a tachyonic instability and exponential pro\
duction of one transverse polarization of the vector field, reaching its maximu\
m near the end of inflation. We show that these polarized transverse vectors ca\
n account for the observed dark matter relic density in the mass range μeV to h\
undreds of GeV. We also find that the tachyonic production mechanism of the tra\
nsverse mode can accommodate larger vector masses and lower Hubble scales of in\
flation compared to the production mechanism for the longitudinal mode via infl\
ationary fluctuations.
