Modifying dark matter indirect detection signals by thermal effects at freeze-out

Abstract

We present an extension of the Standard Model, containing a fermion dark matter candidate and two real scalar singlets, where the observed dark matter abundance is produced via freeze-out before the electroweak phase transition. We show that in this case the dark matter annihilation channels determining its freeze-out are different from those producing indirect detection signal. We present a benchmark model where the indirect annihilation cross-section differs from the freeze-out one. The model also has a gravitational wave signature due to the first order electroweak phase transition.