English
Related papers

Related papers: $P$-partitions and $p$-positivity

200 papers

We provide a construction for the kromatic symmetric function $\overline{X}_G$ of a graph introduced by Crew, Pechenik, and Spirkl using combinatorial (linearly compact) Hopf algebras. As an application, we show that $\overline{X}_G$ has a…

Combinatorics · Mathematics 2025-03-18 Eric Marberg

The dual immaculate and Young quasisymmetric Schur bases of quasisymmetric functions possess analogues in the peak algebra: respectively, the quasisymmetric Schur $Q$-functions and the peak Young quasisymmetric Schur functions. We show…

Combinatorics · Mathematics 2024-06-19 Dominic Searles , Matthew Slattery-Holmes

In 1993, Stanley and Stembridge conjectured that a chromatic symmetric function of any $(3+1)$-free poset is $e$-positive. Guay-Paquet reduced the conjecture to $(3+1)$- and $(2+2)$-free posets which are also called natural unit interval…

Combinatorics · Mathematics 2022-02-15 Seung Jin Lee , Sue Kyong Y. Soh

We define some generalizations of the classical descent and inversion statistics on signed permutations that arise from the work of Sack and Ulfarsson [20] and called after width-k descents and width-k inversionsof type A in Davis's work…

Combinatorics · Mathematics 2022-05-11 Marwa Ben Abdelmaksoud , Adel Hamdi

In this note we classify when a skew Schur function is a positive linear combination of power sum symmetric functions. We then use this to determine precisely when any scalar multiple of a skew Schur function is the chromatic symmetric…

Combinatorics · Mathematics 2018-09-03 Soojin Cho , Stephanie van Willigenburg

Quasi-symmetric functions show up in an approach to solve the Kadomtsev-Petviashvili (KP) hierarchy. This moreover features a new nonassociative product of quasi-symmetric functions that satisfies simple relations with the ordinary product…

Mathematical Physics · Physics 2009-01-19 Aristophanes Dimakis , Folkert Muller-Hoissen

It is known that, under certain conditions, *-representability and extensibility to the unitized *-algebra of a positive linear functional, defined on a *-algebra without unit, are equivalent. In this paper, a new condition for an analogous…

Functional Analysis · Mathematics 2013-12-06 Giorgia Bellomonte

We introduce a generalization of the Stirling numbers via symmetric functions involving two weight functions. The resulting extension unifies previously known Stirling-type sequences with known symmetric function forms, as well as other…

We summarize the known useful and interesting results and formulas we have discovered so far in this collaborative article summarizing results from two related articles by Merca and Schmidt arriving at related so-termed Lambert series…

Number Theory · Mathematics 2017-08-07 Mircea Merca , Maxie D. Schmidt

We extend the big and $p$-typical Witt vector functors from commutative rings to commutative semirings. In the case of the big Witt vectors, this is a repackaging of some standard facts about monomial and Schur positivity in the…

Combinatorics · Mathematics 2015-09-10 James M. Borger

The fundamental quasisymmetric functions in superspace are a generalization of the fundamental quasisymmetric functions involving anticommuting variables. We obtain the action of the product, coproduct, and antipode on the fundamental…

Combinatorics · Mathematics 2024-11-21 Susanna Fishel , Jessica Gatica , Luc Lapointe , Maria Elena Pinto

We study the space, $R_m$, of $m$-symmetric functions consisting of polynomials that are symmetric in the variables $x_{m+1},x_{m+2},x_{m+3},\dots$ but have no special symmetry in the variables $x_1,\dots,x_m$. We obtain $m$-symmetric…

Combinatorics · Mathematics 2025-01-10 Luc Lapointe

We give a new combinatorial interpretation of the stationary distribution of the (partially) asymmetric exclusion process on a finite number of sites in terms of decorated alternative trees and colored permutations. The corresponding…

Combinatorics · Mathematics 2016-06-08 Petter Brändén , Madeleine Leander , Mirkó Visontai

The ring of symmetric functions carries the structure of a Hopf algebra. When computing the coproduct of complete symmetric functions $h_\lambda$ one arrives at weighted sums over reverse plane partitions (RPP) involving binomial…

Combinatorics · Mathematics 2019-07-02 Christian Korff , David Palazzo

In 2015, Jing and Li defined type B quasisymmetric Schur functions and conjectured that these functions have a positive, integral and unitriangular expansion into peak functions. We prove this conjecture, and refine their combinatorial…

Combinatorics · Mathematics 2025-04-08 Ezgi Kantarcı Oğuz

The machinery of noncommutative Schur functions provides a general tool for obtaining Schur expansions for combinatorially defined symmetric functions. We extend this approach to a wider class of symmetric functions, explore its strengths…

Combinatorics · Mathematics 2016-07-12 Jonah Blasiak , Sergey Fomin

We seek simple conditions on a pair of labeled posets that determine when the difference of their $(P,\omega)$-partition enumerators is $F$-positive, i.e., positive in Gessel's fundamental basis. This is a quasisymmetric analogue of the…

Combinatorics · Mathematics 2025-09-17 Nathan R. T. Lesnevich , Peter R. W. McNamara

Tatsuyuki Hikita recently proved the Stanley--Stembridge conjecture using probabilistic methods, showing that the chromatic symmetric functions of unit interval graphs are $e$-positive. Finding a combinatorial interpretation for these…

Combinatorics · Mathematics 2026-02-18 Isaiah Siegl

A common theme of enumerative combinatorics is formed by counting functions that are polynomials evaluated at positive integers. In this expository paper, we focus on four families of such counting functions connected to hyperplane…

Combinatorics · Mathematics 2013-10-07 Matthias Beck

Consider the algebra Q<<x_1,x_2,...>> of formal power series in countably many noncommuting variables over the rationals. The subalgebra Pi(x_1,x_2,...) of symmetric functions in noncommuting variables consists of all elements invariant…

Combinatorics · Mathematics 2007-05-23 Mercedes H. Rosas , Bruce E. Sagan