Nous considérons une marche aléatoire dans un potentiel aléatoire qui modèle la situation d'un polymère aléatoire et nous étudions les coûts “annealed” et “quenched” pour réaliser de longues traversées d'un point à un hyperplan. Ces coûts sont mesurés en terme de normes de Lyapounov. Nous identifions des situations où les normes de Lyapounov d'un point à un hyperplan “annealed” et “quenched” sont différentes. Nous démontrons également que dans ces cas le chemin du polymère présente une localisation.
We consider a random walk in a random potential, which models a situation of a random polymer and we study the annealed and quenched costs to perform long crossings from a point to a hyperplane. These costs are measured by the so called Lyapounov norms. We identify situations where the point-to-hyperplane annealed and quenched Lyapounov norms are different. We also prove that in these cases the polymer path exhibits localization.
Mots clés : random walks, random potential, Lyapounov norms, strong disorder, localization, fractional moments
@article{AIHPB_2013__49_3_753_0, author = {Zygouras, N.}, title = {Strong disorder in semidirected random polymers}, journal = {Annales de l'I.H.P. Probabilit\'es et statistiques}, pages = {753--780}, publisher = {Gauthier-Villars}, volume = {49}, number = {3}, year = {2013}, doi = {10.1214/12-AIHP483}, mrnumber = {3112433}, language = {en}, url = {http://www.numdam.org/articles/10.1214/12-AIHP483/} }
TY - JOUR AU - Zygouras, N. TI - Strong disorder in semidirected random polymers JO - Annales de l'I.H.P. Probabilités et statistiques PY - 2013 SP - 753 EP - 780 VL - 49 IS - 3 PB - Gauthier-Villars UR - http://www.numdam.org/articles/10.1214/12-AIHP483/ DO - 10.1214/12-AIHP483 LA - en ID - AIHPB_2013__49_3_753_0 ER -
Zygouras, N. Strong disorder in semidirected random polymers. Annales de l'I.H.P. Probabilités et statistiques, Tome 49 (2013) no. 3, pp. 753-780. doi : 10.1214/12-AIHP483. http://www.numdam.org/articles/10.1214/12-AIHP483/
[1] A note on the diffusion of directed polymers in a random environment. Comm. Math. Phys. 123 (1989) 529-534. | MR | Zbl
.[2] On the static and dynamic points of view for certain random walks in random environment. Methods Appl. Anal. 9 (2002) 345-375. Special issue dedicated to Daniel W. Stroock and Srinivasa S. R. Varadhan on the occasion of their 60th birthday. | MR | Zbl
and .[3] Ornstein-Zernike theory for finite range Ising models above . Probab. Theory Related Fields 125 (2003) 305-349. | MR | Zbl
, and .[4] Ornstein-Zernike behavior for self-avoiding walks at all noncritical temperatures. Comm. Math. Phys. 105 (1986) 221-238. | MR
and .[5] Directed polymers in random environment are diffusive at weak disorder. Ann. Probab. 34 (2006) 1746-1770. | MR | Zbl
and .[6] Probabilistic analysis of directed polymers in a random environment: A review. In Stochastic Analysis on Large Scale Interacting Systems 115-142. Adv. Stud. Pure Math. 39. Math. Soc. Japan, Tokyo, 2004. | MR | Zbl
, and .[7] Coincidence of Lyapunov exponents for random walks in weak random potentials. Ann. Probab. 36 (2008) 1528-1583. | MR | Zbl
.[8] Marginal relevance of disorder for pinning models. Comm. Pure Appl. Math. 63 (2010) 233-265. | MR | Zbl
, and .[9] Crossing random walks and stretched polymers at weak disorder. Available at arXiv:1002.4289. | MR | Zbl
and .[10] Ballistic phase of self-interacting random walks. In Analysis and Stochastics of Growth Processes and Interface Models 55-79. Oxford Univ. Press, Oxford, 2008. | MR | Zbl
and .[11] Stretched polymers in random environment. Available at arXiv:1011.0266. | Zbl
and .[12] First passage percolation. In From Classical to Modern Probability 93-143. Progr. Probab. 54. Birkhäuser, Basel, 2003. | MR | Zbl
.[13] Lyapunov exponents of Green's functions for random potentials tending to zero. Probab. Theory Related Fields 150 (2011) 43-59. | MR | Zbl
, and .[14] New bounds for the free energy of directed polymer in dimension 11 and 12. Comm. Math. Phys. 294 (2010) 471-503. | MR | Zbl
.[15] Annealed Lyapounov exponents and large deviations in a Poissonian potential. I. Ann. Sci. Éc. Norm. Supér. 28 (1995) 345-370. | Numdam | MR | Zbl
.[16] Brownian motion with a drift in a Poissonian potential. Comm. Pure Appl. Math. 47 (1994) 1283-1318. | MR | Zbl
.[17] Brownian Motion, Obstacles and Random Media. Springer Monographs in Mathematics. Springer, Berlin, 1998. | MR | Zbl
.[18] Phase transitions and fluctuations for random walks with drift in random potentials. Ph.D. thesis, Univ. Zurich.
.[19] Strong localization and macroscopic atoms for directed polymers. Probab. Theory Related Fields 138 (2007) 391-410. | MR | Zbl
.[20] Directional decay of the Green’s function for a random nonnegative potential on . Ann. Appl. Probab. 8 (1998) 246-280. | MR | Zbl
.[21] Lyapounov norms for random walks in low disorder and dimension greater than three. Probab. Theory Related Fields 143 (2009) 615-642. | MR | Zbl
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