Peculiarity of the Coulombic Criticality ?

Abstract

We indicate that Coulombic systems could correspond to Wilson effective Hamiltonians similar to that of the ordinary (nonionic) fluids but with a negative $\phi^4$-coefficient. In that case, solving the ``exact'' renormalization group equation in the local potential approximation, we show that close initial Hamiltonians may lead either to a first order transition or to an Ising-like critical behavior, the partition being formed by the tri-critical surface. Hence the theoretical wavering encountered in the literature concerning the nature of the Coulombic criticality may not appear senseless.