Biomedical subjects

JL Jacobsen

Publications and source records attributed to JL Jacobsen.

3 recordsLinked to original sources

PubMed2000

Large-q asymptotics of the random-bond potts model

We numerically examine the large-q asymptotics of the q-state random bond Potts model. Special attention is paid to the parametrization of the critical line, which is determined by combining the loop representation of the transfer matrix with Zamolodchikov's c-theorem. Asymptotically the central charge seems to behave like c(q)=1 / 2 log(2)(q)+O(1). Very accurate values of the bulk magnetic exponent x(1) are then extracted by performing Monte Carlo simulations directly at the critical point. As q-->infinity, these seem to tend to a nontrivial limit, x(1)-->0.192+/-0.002.

Journal Article↗

PubMed2000

Multiscaling of energy correlations in the random-bond potts model

We numerically calculate the exponents governing the disorder averaged and fixed-sample decay of the energy-energy correlator in the q-state random-bond Potts model. Our results are in good agreement with a two-loop expansion around q=2 recently found from perturbative renormalization group techniques, fulfill the correlation length bound nu>/=2/d, and give further evidence against replica symmetry breaking in this class of models.

Journal Article↗

PubMed2000

Duality relations for M coupled potts models

We establish explicit duality transformations for systems of M q-state Potts models coupled through their local energy density, generalizing known results for M=1,2,3. The M-dimensional space of coupling constants contains a self-dual submanifold of dimension D(M)=[M/2]. For the case M=4, the variation of the effective central charge along the self-dual surface is investigated by numerical transfer matrix techniques. Evidence is given for the existence of a family of critical points, corresponding to conformal field theories with an extended S(M) symmetry algebra.

Journal Article↗