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On Seneta–Heyde scaling for a stable branching random walk

Published online by Cambridge University Press:  26 July 2018

Hui He*
Affiliation:
Beijing Normal University
Jingning Liu*
Affiliation:
Beijing Normal University
Mei Zhang*
Affiliation:
Beijing Normal University
*
* Postal address: Laboratory of Mathematics and Complex Systems, School of Mathematical Sciences, Beijing Normal University, Beijing, 100875, P. R. China.
* Postal address: Laboratory of Mathematics and Complex Systems, School of Mathematical Sciences, Beijing Normal University, Beijing, 100875, P. R. China.
* Postal address: Laboratory of Mathematics and Complex Systems, School of Mathematical Sciences, Beijing Normal University, Beijing, 100875, P. R. China.

Abstract

We consider a discrete-time branching random walk in the boundary case, where the associated random walk is in the domain of attraction of an α-stable law with 1 < α < 2. We prove that the derivative martingale Dn converges to a nontrivial limit D under some regular conditions. We also study the additive martingale Wn and prove that n1/αWn converges in probability to a constant multiple of D.

Type
Original Article
Copyright
Copyright © Applied Probability Trust 2018 

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References

[1]Aïdékon, E. (2013). Convergence in law of the minimum of a branching random walk. Ann. Prob. 41, 13621426. Google Scholar
[2]Aïdékon, E. and Jaffuel, B. (2011). Survival of branching random walks with absorption. Stoch. Process. Appl. 121, 19011937. Google Scholar
[3]Aïdékon, E. and Shi, Z. (2010). Weak convergence for the minimal position in a branching random walk: a simple proof. Period. Math. Hungar. 61, 4354. Google Scholar
[4]Aïdékon, E. and Shi, Z. (2014). The Seneta–Heyde scaling for the branching random walk. Ann. Prob. 42, 959993. Google Scholar
[5]Barral, J. (2000). Differentiability of multiplicative processes related to branching random walks. Ann. Inst. H. Poincaré Prob. Statist. 36, 407417. Google Scholar
[6]Biggins, J. D. (1977). Martingale convergence in the branching random walk. J. Appl. Prob. 14, 2537. Google Scholar
[7]Biggins, J. D. (1991). Uniform convergence of martingales in the one-dimensional branching random walk. In Selected Proceedings of the Sheffield Symposium an Applied Probability (IMS Lecture Notes Monogr. Ser. 18), Institute of Mathematical Statistics, Hayward, CA, pp. 159173. Google Scholar
[8]Biggins, J. D. (1992). Uniform convergence of martingales in the branching random walk. Ann. Prob. 20, 137151. Google Scholar
[9]Biggins, J. D. (2003). Random walk conditioned to stay positive. J. London Math. Soc. (2) 67, 259272. Google Scholar
[10]Biggins, J. D. (2010). Branching out. In Probability and Mathematical Genetics (London Math. Soc. Lecture Note Ser. 378), Cambridge University Press, pp. 113134. Google Scholar
[11]Biggins, J. D. and Kyprianou, A. E. (1996). Branching random walk: Seneta–Heyde norming. In Trees (Versailles, 1995; Progr. Prob. 40), Birkhäuser, Basel, pp. 3149. Google Scholar
[12]Biggins, J. D. and Kyprianou, A. E. (1997). Seneta–Heyde norming in the branching random walk. Ann. Prob. 25, 337360. Google Scholar
[13]Biggins, J. D. and Kyprianou, A. E. (2004). Measure change in multitype branching. Adv. Appl. Prob. 36, 544581. Google Scholar
[14]Biggins, J. D. and Kyprianou, A. E. (2005). Fixed points of the smoothing transform: the boundary case. Electron. J. Prob. 10, 609631. Google Scholar
[15]Bingham, N. H. (1973). Limit theorems in fluctuation theory. Adv. Appl. Prob. 5, 554569. Google Scholar
[16]Bingham, N. H. (1973). Maxima of sums of random variables and suprema of stable processes. Z. Wahrscheinlichkeitsth. 26, 273296. Google Scholar
[17]Caravenna, F. and Chaumont, L. (2013). An invariance principle for random walk bridges conditioned to stay positive. Electron. J. Prob. 18, 60. Google Scholar
[18]Chen, X. (2015). A necessary and sufficient condition for the nontrivial limit of the derivative martingale in a branching random walk. Adv. Appl. Prob. 47, 741760. Google Scholar
[19]Chung, K. L. (2001). A Course in Probability Theory, 3rd edn. Academic Press, San Diego, CA. Google Scholar
[20]Feller, W. (1971). An Introduction to Probability Theory and Its Applications, Vol. II, 2nd edn. John Wiley, New York. Google Scholar
[21]Heyde, C. C. (1970). Extension of a result of Seneta for the super-critical Galton–Watson process. Ann. Math. Statist. 41, 739742. Google Scholar
[22]Hu, Y. and Shi, Z. (2009). Minimal position and critical martingale convergence in branching random walks, and directed polymers on disordered trees. Ann. Prob. 37, 742789. Google Scholar
[23]Jaffuel, B. (2012). The critical barrier for survival of branching random walk with absorption. Ann. Inst. H. Poincaré Prob. Statist. 48, 9891009. Google Scholar
[24]Kyprianou, A. E. (1998). Slow variation and uniqueness of solutions to the functional equation in the branching random walk. J. Appl. Prob. 35, 795801. Google Scholar
[25]Liu, Q. (2000). On generalized multiplicative cascades. Stoch. Process. Appl. 86, 263286. Google Scholar
[26]Lyons, R. (1997). A simple path to Biggins' martingale convergence for branching random walk. In Classical and Modern Branching Processes (IMA Vol. Math. Appl. 84), Springer, New York, pp. 217221. Google Scholar
[27]Rogozin, B. A. (1964). On the distribution of the first jump. Theory Prob. Appl. 9, 450465. Google Scholar
[28]Rogozin, B. A. (1971). The distribution of the first ladder moment and height and fluctuation of a random walk. Theory Prob. Appl. 16, 575595. Google Scholar
[29]Seneta, E. (1968). On recent theorems concerning the supercritical Galton–Watson process. Ann. Math. Statist. 39, 20982102. Google Scholar
[30]Sinai, Ya. G. (1957). On the distribution of the first positive sum for a sequence of independent random variables. Theory Prob. Appl 2, 122129. Google Scholar
[31]Tanaka, H. (1989). Time reversal of random walks in one-dimension. Tokyo J. Math. 12, 159174. Google Scholar
[32]Vatutin, V. A. and Wachtel, V. (2009). Local probabilities for random walks conditioned to stay positive. Prob. Theory Relat. Fields 143, 177217. Google Scholar