On the self-interacting dark matter in galaxies.

M. Carinci, R. Ruffini

III - Astrofisica
Aula GSSI Rettorato - Auditorium - Mercoledì 25 h 16:30 - 19:00
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For several decades there has been comparing evidence of the system of dark matter of the galactic case. There exists in the literature different approaches to the distribution of dark matter, such as the NFW profile or the semi-analytic RAR Model for a self-gravitating system of elementary KeV fermions, which is based on the equations of gravitational equilibrium, in the general relativity framework, together with the thermodynamic equilibrium conditions. But there is evidence that the DM is also self-interacting, motivated by the increasing observational bound on the dark-matter cross-section. In this work, we consider the inclusion of self-interactions among the dark matter fermions. More specifically, we work in the Lagrangian mean field theory approach which includes the coupling constant $C_{\nu}$. We calculate the effect on the morphology of the DM profile. We further calculate the $C_{\nu}$ at which we have changes in the halo, for each kind of galaxy. We also show how the effect of the self-interacting term is connected to the temperature, and how we must change the other parameters (i.e. the chemical potential). In particular, we analyse the case of vlusters, where there are more applications with a -ino mass of 1--10 MeV. Finally, we shall calculate the cross sections, finding strong constraints for $C_{\nu}$, if we would use the perturbative Lagrangian approach.

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