Understanding the nature of the Dark Matter ( DM ) is one of the current challenges in modern astrophysics and cosmology .
Knowing the properties of the DM particle would shed light on physics beyond the Standard Model and even provide us with details of the early Universe .
In fact , the detection of such a relic would bring us information from the pre-Big Bang Nucleosynthesis ( BBN ) period , an epoch from which we have no direct data , and could even hint at inflation physics .
In this work , we assume that the expansion rate of the Universe after inflation is governed by the kinetic energy of a scalar field \phi , in the so-called “ kination ” model .
Adding to previous work on the subject , we assume that the \phi field decays into both radiation and DM particles , which we take to be Weakly Interacting Massive Particles ( WIMPs ) .
The present abundance of WIMPs is then fixed during the kination period through either a thermal “ freeze-out ” or “ freeze-in ” mechanism , or through a non-thermal process governed by the decay of \phi .
We explore the parameter space of this theory with the requirement that the present WIMP abundance provides the correct relic budget .
Requiring that BBN occurs during the standard cosmological scenario sets a limit on the temperature at which the kination period ends .
Using this limit and assuming the WIMP has a mass m _ { \chi } = 100 GeV , we obtain that the thermally-averaged WIMP annihilation cross section has to satisfy the constraints 4 \times 10 ^ { -16 } { GeV ^ { -2 } } \lesssim \langle \sigma v \rangle \lesssim 2 \times 1 % 0 ^ { -5 } { GeV ^ { -2 } } in order for having at least one of the production mechanism to yield the observed amount of DM .
This result shows how the properties of the WIMP particle , if ever measured , can yield information on the pre-BBN content of the Universe .