
pages 137-150
Available online: 20 Jan 2009We show that for each permutation w containing no decreasing subsequence of length k, the Kazhdan–Lusztig immanant Imm w (x) vanishes on all matrices having k equal rows or columns. Also, we define two filtrations of the vector space of immanants via products of matrix minors and pattern avoidance and use the above result to show that these filtrations are equivalent. Finally, we construct new and simple inequalities satisfied by the minors of totally nonnegative matrices.