Inertia of Loewner matrices

Article Type

Research Article

Publication Title

Indiana University Mathematics Journal

Abstract

Given positive numbers p1 < p2 < ⋯ < pn and a real number r, let Lr be the n x n matrix with its i, j entry equal to (pir - pjr)/(pi - pj). A well-known theorem of C. Loewner says that Lr is positive definite when 0 < r < 1. In contrast, R. Bhatia and J. Holbrook (Indiana Univ. Math. J, 49 (2000), 1153-1173) showed that when 1 < r < 2, the matrix Lr has only one positive eigenvalue, and made a conjecture about the signatures of eigenvalues of Lr for other values of r. That conjecture is proved in this paper.

First Page

1251

Last Page

1261

DOI

10.1512/iumj.2016.65.5869

Publication Date

1-1-2016

Comments

Open Access; Green Open Access

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