Numerical study of the disordered Poland-Scheraga model of DNA denaturation

dc.creatorGarel, Thomas
dc.creatorMonthus, Cecile
dc.date2005-04-05
dc.date2005-05-25
dc.date.accessioned2026-07-07T03:04:26Z
dc.date.available2026-07-07T03:04:26Z
dc.descriptionWe numerically study the binary disordered Poland-Scheraga model of DNA denaturation, in the regime where the pure model displays a first order transition (loop exponent $c=2.15>2$). We use a Fixman-Freire scheme for the entropy of loops and consider chain length up to $N=4 \cdot 10^5$, with averages over $10^4$ samples. We present in parallel the results of various observables for two boundary conditions, namely bound-bound (bb) and bound-unbound (bu), because they present very different finite-size behaviors, both in the pure case and in the disordered case. Our main conclusion is that the transition remains first order in the disordered case: in the (bu) case, the disorder averaged energy and contact densities present crossings for different values of $N$ without rescaling. In addition, we obtain that these disorder averaged observables do not satisfy finite size scaling, as a consequence of strong sample to sample fluctuations of the pseudo-critical temperature. For a given sample, we propose a procedure to identify its pseudo-critical temperature, and show that this sample then obeys first order transition finite size scaling behavior. Finally, we obtain that the disorder averaged critical loop distribution is still governed by $P(l) \sim 1/l^c$ in the regime $l \ll N$, as in the pure case.
dc.description12 pages, 13 figures. Revised version
dc.identifierhttps://arxiv.org/abs/cond-mat/0504094
dc.identifierhttp://arxiv.org/abs/cond-mat/0504094
dc.identifierJ. Stat. Mech. (2005) P06004
dc.identifierdoi:10.1088/1742-5468/2005/06/P06004
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/26136
dc.subjectDisordered Systems and Neural Networks
dc.subjectSoft Condensed Matter
dc.titleNumerical study of the disordered Poland-Scheraga model of DNA denaturation
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