# Positivity of some multivariate formal power series arising from fractional powers of determinants

Speaker:
Alan Sokal (NYU and UCL)
Date/Time:
Fri, 17/03/2017 - 16:00
Room:
Queen's building W316
Seminar series:

We prove the coefficientwise positivity for a class of multivariate formal power series that arise as fractional powers of determinants. More precisely, we show that the formal power series $1 - \det(I_n - tA_n)^{1/n}$ is coefficientwise nonnegative when $A_n$ is an $n \times n$ matrix built in a suitable way out of $n^2$ independent indeterminates.

This is joint work with Alex Scott.