Source: Ann. Probab. Volume 32, Number 3B
(2004), 2650-2701.
Vertex-reinforced random walk (VRRW), defined by Pemantle in 1988, is a random process that takes values in the vertex set of a graph G, which is more likely to visit vertices it has visited before. Pemantle and Volkov considered the case when the underlying graph is the one-dimensional integer lattice ℤ. They proved that the range is almost surely finite and that with positive probability the range contains exactly five points. They conjectured that this second event holds with probability 1. The proof of this conjecture is the main purpose of this paper.
References
Benaïm, M. (1997). Vertex-reinforced random walks and a conjecture of Pemantle. Ann. Probab. 25 361--392.
Benaïm, M. (1999). Dynamics of stochastic approximation algorithms. Séminaire de Probabilités XXXIII. Lecture Notes in Math. 1709 1--68. Springer, Berlin.
Bienvenüe, A. (1999). Contribution à l'étude des marches aléatoires avec mémoire. Ph.D. dissertation, Univ. Claude Bernard Lyon 1.
Coppersmith, D. and Diaconis, P. (1986). Random walks with reinforcement. Unpublished manuscript.
Feller, W. (1957, 1968). An Introduction to Probability Theory and Its Applications 1, 2. Wiley, New York.
Neveu, J. (1975). Discrete Parameter Martingales. North-Holland, Amsterdam.
Mathematical Reviews (MathSciNet):
MR402915
Pemantle, R. (1988). Random processes with reinforcement. Ph.D. dissertation, Massachussets Institute of Technology.
Pemantle, R. (1992). Vertex-reinforced random walk. Probab. Theory Related Fields 92 117--136.
Pemantle, R. and Volkov, S. (1999). Vertex-reinforced random walk on $\Z$ has finite range. Ann. Probab. 27 1368--1388.
Sellke, T. (1994). Reinforced random walk on the $d$-dimensionnal integer lattice. Technical Report 94-26, Dept. Statistics, Purdue Univ.
Tarrès, P. (2000). Pièges répulsifs. C. R. Acad. Sci. Paris Sér. I Math. 330 125--130.
Tarrès, P. (2001). Pièges des algorithmes stochastiques et marches aléatoires renforcées par sommets. Ph.D. dissertation, École Normale Supérieure de Cachan. Available at www.lsp.ups-tlse.fr/Fp/Tarres/.
Volkov, S. (2001). Vertex-reinforced random walk on arbitrary graphs. Ann. Probab. 29 66--91.