摘要

Consider a branching random walk, where the underlying branching mechanism is governed by a Galton-Watson process and the migration of particles by a simple random walk in Z(d). Denote by Z(n) (z) the number of particles of generation n located at site z is an element of Z(d). We give the second order asymptotic expansion for Z(n) (z). The higher order expansion can be derived by using our method here. As a by-product, we give the second order expansion for a simple random walk on Z(d), which is used in the proof of the main theorem and is of independent interest.

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