Ultra logconcave sequences and negative dependence

[摘要] We prove that the convolution of two ultra-logconcave sequences is ultra-logconcave. This was conjectured recently by Pemantle and implies that a natural negative dependence property is preserved under the operation of ''joining'' families of exchangeable Bernoulli random variables. (C) 1997 Academic Press.

[发布日期] 1997-08-01