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arXiv · 1506.08382

A combinatorial identity on Galton-Watson process

Linyuan Lu·Arthur L. B. Yang
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Abstract

Let $f(m,c)=\sum_{k=0}^{\infty} (km+1)^{k-1} c^k e^{-c(km+1)/m} / (m^kk!)$. For any positive integer $m$ and positive real $c$, the identity $f(m,c)=f(1,c)^{1/m}$ arises in the random graph theory. In this paper, we present two elementary proofs of this identity: a pure combinatorial proof and a power-serial proof. We also proved that this identity holds for any positive reals $m$ and $c$.

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Linyuan Lu, Arthur L. B. Yang. 2015-06-28. A combinatorial identity on Galton-Watson process. https://arxiv.org/abs/1506.08382

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