The quenched limiting distributions of a charged-polymer model

Abstract

The limit distributions of the charged-polymer Hamiltonian of Kantor and Kardar [Bernoulli case] and Derrida, Griffiths and Higgs [Gaussian case] are considered. Two sources of randomness enter in the definition: a random field $q= (q_i)_{i\geq 1}$ of i.i.d. random variables (called random charges) and a random walk $S = (S_n)_{n \in \mathbb{N}}$ evolving in $\mathbb{Z}^d$, independent of the charges. The energy or Hamiltonian $K = (K_n)_{n \geq 2}$ is then defined as $$K_n := \sum_{1\leq i < j\leq n} q_i q_j {\bf 1}_{\{S_i=S_j\}}.$$ The law of $K$ under the joint law of $q$ and $S$ is called "annealed", and the conditional law given $q$ is called "quenched". Recently, strong approximations under the annealed law were proved for $K$. In this paper we consider the limit distributions of $K$ under the quenched law.