The Vlasov-Poisson system with massless electrons (VPME) is widely used in
plasma physics to model the evolution of ions in a plasma. It differs from the
classical Vlasov-Poisson system (VP) in that the Poisson coupling has an
exponential nonlinearity that creates several mathematical difficulties. In
particular, while the global well-posedness in 3D is well understood in the
classical case, this problem remained completely open for massless electrons.
The aim of this paper is to fill this gap by proving uniqueness for VPME in the
class of solutions with bounded density, and global existence of solutions with
bounded density for a general class of initial data, generalising to this
setting all the previous results known for VP.