-partitions and a multi-parameter Klyachko idempotent.
Parabolic bundles, products of conjugacy classes, and Gromov-Witten invariants
The set of conjugacy classes appearing in a product of conjugacy classes in a compact, -connected Lie group can be identified with a convex polytope in the Weyl alcove. In this paper we identify linear inequalities defining this polytope. Each inequality corresponds to a non-vanishing Gromov-Witten invariant for a generalized flag variety , where is the complexification of and is a maximal parabolic subgroup. This generalizes the results for of Agnihotri and the second author and Belkale on...
Parking functions and noncrossing partitions.
Partitions, rooks, and symmetric functions in noncommuting variables.
Paths and tableaux descriptions of Jacobi-Trudi determinant associated with quantum affine algebra of type .
Pattern avoidance in partial permutations.
Pebblings.
Permutations with Kazhdan-Lusztig polynomial . With an appendix by Sara Billey and Jonathan Weed.
Permutations without long decreasing subsequences and random matrices.
Pieri's formula for flag manifolds and Schubert polynomials
We establish the formula for multiplication by the class of a special Schubert variety in the integral cohomology ring of the flag manifold. This formula also describes the multiplication of a Schubert polynomial by either an elementary or a complete symmetric polynomial. Thus, we generalize the classical Pieri’s formula for Schur polynomials (associated to Grassmann varieties) to Schubert polynomials (associated to flag manifolds). Our primary technique is an explicit geometric description of certain...
Plancherel averages: remarks on a paper by Stanley.
Plethysm and the non-compact groups .
Poincaré polynomials for unitary reflection groups.
Poset homology of Rees products, and -Eulerian polynomials.
Positivity for special cases of -Kostka coefficients and standard tableaux statistics.
Positivity in coefficient-free rank two cluster algebras.
Positivity of Schur function expansions of Thom polynomials
Combining the approach to Thom polynomials via classifying spaces of singularities with the Fulton-Lazarsfeld theory of cone classes and positive polynomials for ample vector bundles, we show that the coefficients of the Schur function expansions of the Thom polynomials of stable singularities are nonnegative with positive sum.
Positivity of the -system cluster algebra.
Positivity of Thom polynomials II: the Lagrange singularities
We study Thom polynomials associated with Lagrange singularities. We expand them in the basis of Q̃-functions. This basis plays a key role in the Schubert calculus of isotropic Grassmannians. We prove that the Q̃-function expansions of the Thom polynomials of Lagrange singularities always have nonnegative coefficients. This is an analog of a result on the Thom polynomials of mapping singularities and Schur S-functions, established formerly by the last two authors.
Pretty cleanness and filter-regular sequences
Let be a field and . Let be a monomial ideal of and be monomials in . We prove that if form a filter-regular sequence on , then is pretty clean if and only if is pretty clean. Also, we show that if form a filter-regular sequence on , then Stanley’s conjecture is true for if and only if it is true for . Finally, we prove that if is a minimal set of generators for which form either a -sequence, proper sequence or strong -sequence (with respect to the reverse lexicographic...