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Article
Infinite Log-concavity: Developments and Conjectures
Faculty Journal Articles
  • Peter McNamara, Bucknell University
  • Bruce Sagan, Michigan State University
Publication Date
1-1-2010
Description

Given a sequence (ak)=a0,a1,a2,… of real numbers, define a new sequence L(ak)=(bk) where . So (ak) is log-concave if and only if (bk) is a nonnegative sequence. Call (ak)infinitely log-concave if Li(ak) is nonnegative for all i⩾1. Boros and Moll conjectured that the rows of Pascal's triangle are infinitely log-concave. Using a computer and a stronger version of log-concavity, we prove their conjecture for the nth row for all n⩽1450. We also use our methods to give a simple proof of a recent result of Uminsky and Yeats about regions of infinite log-concavity. We investigate related questions about the columns of Pascal's triangle, q-analogues, symmetric functions, real-rooted polynomials, and Toeplitz matrices. In addition, we offer several conjectures.

Disciplines
Journal
Advances in Applied Mathematics
Department
Mathematics
Citation Information
Peter McNamara and Bruce Sagan. "Infinite Log-concavity: Developments and Conjectures" Vol. 44 Iss. 1 (2010) p. 1 - 15
Available at: http://works.bepress.com/peter_mcnamara/11/