Seminarium "Teoria cząstek elementarnych i kosmologia"

A systematic approach will be presented to establish the connection between cosmic microwave background (CMB) observables and the reheating temperature (TR). Combining this connection with model-independent bounds on TR and CMB measurements allows us to (i) discriminate between different models of inflation and (ii) test particle physics scenarios sensitive to TR. We will illustrate this approach using alpha-attractor models of inflation and TR-dependent freeze-in dark matter (DM) production. One consequence of the model-independent bounds on TR is that the inflationary models predict narrow allowed ranges of the scalar spectral index, with a nontrivial dependence on the tensor-to-scalar ratio. For certain inflaton potentials, these ranges are further narrowed when the effects of non-perturbative fragmentation of the inflaton condensate are taken into account. The measured CMB observables can also impose significant constraints on the parameter space of freeze-in DM models, providing a consistency test between DM production and models of cosmic inflation.