Constraints on dark matter self-interaction from galactic core size
  Self interaction of particulate dark matter may help thermalising the
galactic center and driving core formation. The core radius is expectantly
sensitive to the self interaction strength of dark matter. In this paper we
study the feasibility of constraining dark matter self interaction from the
distribution of the core radius in isolated haloes. We perform systematic
$N$-body simulations of isolated galactic haloes in the mass range of $10^{10}
$-$10^{15}M_{\odot}$ incorporating the impact of DM self interactions.
Comparing the simulated profiles with observational data provides conservative
upper limit on the self coupling cross-section $ \sigma/m_{\rm DM} < $ $ 9.8 $
$\ \rm cm^2 /\rm gm $ at $ 95 \% $ confidence level. We report significant
dependence of the derived bounds on the galactic density distribution models
assumed in the analysis.
