%0 Journal Article %T Kinetic transport in the two-dimensional periodic Lorentz gas %A Jens Marklof %A Andreas Strombergsson %J Mathematics %D 2008 %I arXiv %R 10.1088/0951-7715/21/7/001 %X The periodic Lorentz gas describes an ensemble of non-interacting point particles in a periodic array of spherical scatterers. We have recently shown that, in the limit of small scatterer density (Boltzmann-Grad limit), the macroscopic dynamics converges to a stochastic process, whose kinetic transport equation is not the linear Boltzmann equation--in contrast to the Lorentz gas with a disordered scatterer configuration. The present paper focuses on the two-dimensional set-up, and reports an explicit, elementary formula for the collision kernel of the transport equation. %U http://arxiv.org/abs/0804.0566v1