We consider the equation $$x^{\text{'}\text{'}}+a^2\left(t\right)x=0,a\left(t\right):=a_k\text{if}{t}_{k-1}\le t<t_k,\text{for}k=1,2,...,$$ where $\left\{a_k\right\}$ is a given increasing sequence of positive numbers, and $\left\{t_k\right\}$ is chosen at random so that $\{t_k-t_{k-1}\}$ are totally independent random variables uniformly distributed on interval $[0,1]$. We determine the probability of the event that all solutions of the equation tend to zero as $t\to \infty$.

In this note, we prove an asymptotic expansion and a central limit theorem for the multiple overlap R1, ..., s of the SK model, defined for given N, s ≥ 1 by R1, ..., s = N-1Σi≤N σ1i ... σsi. These results are obtained by a careful analysis of the terms appearing in the cavity derivation formula, as well as some graph induction procedures. Our method could hopefully be applied to other spin glasses models.

The Parisi formula is an expression for the limiting free energy of the Sherrington-Kirkpatrick spin glass model, which had first been derived by Parisi using a non-rigorous replica method together with an hierarchical ansatz for the solution of the variational problem. It had become quickly clear that behind the solution, if correct, lies an interesting mathematical structure. The formula has recently been proved by Michel Talagrand based partly on earlier ideas and results by Francesco Guerra....