%0 Journal Article %T Stability for the spherically symmetric Einstein-Vlasov system - a coercivity estimate %A Mahir Hadzic %A Gerhard Rein %J Physics %D 2012 %I arXiv %R 10.1017/S030500411300056X %X The stability of static solutions of the spherically symmetric, asymptotically flat Einstein-Vlasov system is studied using a Hamiltonian approach based on energy-Casimir functionals. The main result is a coercivity estimate for the quadratic part of the expansion of the natural energy-Casimir functional about an isotropic steady state. The estimate shows in a quantified way that this quadratic part is positive definite on a class of linearly dynamically accessible perturbations, provided the particle distribution of the steady state is a strictly decreasing function of the particle energy and provided the steady state is not too relativistic. This should be an essential step in a fully non-linear stability analysis for the Einstein-Vlasov system. In the present paper it is exploited for obtaining a linearized stability result. %U http://arxiv.org/abs/1205.6198v1