Positive expansions of permuted basement and quasisymmetric Macdonald polynomials at $t=0$

Olya Mandelshtam, Harper Niergarth, Kartik Singh

It is well known that the $q$-Whittaker polynomials, which are $t=0$ specializations of the Macdonald polynomials $P_{\lambda }(X;q,t)$, expand positively as the sum of Schur polynomials. M…