Department of Statistics & Actuarial Science: Asymptotic expansions of central limit theorems


2:00 PM - 3:00 PM

MB 541/ Zhumu Meeting


  • Date: April 23, 2021, Friday
  • Time: 14:00 – 15:00
  • Venue: MB541, Math Building / Zhumu Meeting
  • Organiser: Department of Statistics & Actuarial Science
  • Scan for Zhumu:


Harris proposed the question on the Central Limit Theorems for a branching random walk in 1963. Since then, the topic received much attention. Specially, in 1994, Revesz started the research on convergence rates of the central limit theorems for branching random walks where the migration law is governed by simple random walks or Wiener processes. Chen (2001) verified Revesz’s conjecture on exact convergence rate. In a series of works, we improve and generalize Chen’s results. More precisely, we improve Chen’s results by weakening the moment conditions on the branching mechanism of the models he considered, then we give the further expansion for those models. Moreover, we extend these results to general cases where the migration law are governed by random walks on Rd or Zd, as well for branching random walks in random environments where both the branching mechanism and migration laws vary with time.


Dr Zhiqiang Gao is an Associate Professor at School of Mathematical Sciences, Beijing Normal University. He received his PhD degree in Probability from University of South Brittany, France in 2011. His interests include probability theory and complex analysis. His main research results are published in international journals including Bernoulli, Stochastic Processes and Their applications, Ann Inst Henri Poincaré, Markov Processes and Related Fields.

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