Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-17T16:12:34.011Z Has data issue: false hasContentIssue false

Negative Association Does not Imply Log-Concavity of the Rank Sequence

Published online by Cambridge University Press:  14 July 2016

Klas Markström*
Affiliation:
Umeå University
*
Postal address: Department of Mathematics and Mathematical Statistics, Umeå University, SE-901 87 Umeå, Sweden. Email address: klas.markstrom@math.umu.se
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We present a minimum counterexample to the conjecture that a negatively associated random variable has an ultra-log-concave rank sequence. The rank sequence does not in fact even need to be unimodal.

Type
Short Communications
Copyright
Copyright © Applied Probability Trust 2007 

References

[1] Borcea, J., Brändén, P. and Liggett, T. M. (2007). Negative dependence and the geometry of polynomials. Available at http://www.arxiv.org/abs/0707.2340.Google Scholar
[2] Liggett, T. M. (1997). Ultra logconcave sequences and negative dependence. J. Combin. Theory Ser. A 79, 315325.Google Scholar
[3] Pemantle, R. (2000). Towards a theory of negative dependence. Probabilistic techniques in equilibrium and nonequilibrium statistical physics. J. Math. Phys. 41, 13711390.Google Scholar