Results 61 to 70 of about 1,020 (80)

Classical pattern distributions in $\mathcal{S}_{n}(132)$ and $\mathcal{S}_{n}(123)$ [PDF]

Discrete Mathematics & Theoretical Computer Science, 2019
Classical pattern avoidance and occurrence are well studied in the symmetric group $\mathcal{S}_{n}$. In this paper, we provide explicit recurrence relations to the generating functions counting the number of classical pattern occurrence in the set of ...
Dun Qiu, Jeffrey Remmel
doaj   +1 more source

Key-avoidance for alternating sign matrices [PDF]

Discrete Mathematics & Theoretical Computer Science
We initiate a systematic study of key-avoidance on alternating sign matrices (ASMs) defined via pattern-avoidance on an associated permutation called the \emph{key} of an ASM.
Mathilde Bouvel, Rebecca Smith, Jessica Striker   +2 more
doaj   +1 more source

Distribution of sets of descent tops and descent bottoms on restricted permutations [PDF]

Discrete Mathematics & Theoretical Computer Science
In this note, we prove some and conjecture other results regarding the distribution of descent top and descent bottom sets on some pattern-avoiding permutations.
Alexander Burstein
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K-Orbit closures and Hessenberg varieties

Forum of Mathematics, Sigma
This article explores the relationship between Hessenberg varieties associated with semisimple operators with two eigenvalues and orbit closures of a spherical subgroup of the general linear group.
Mahir Bilen Can, Martha Precup, John Shareshian, Özlem Uğurlu   +3 more
doaj   +1 more source

Involution factorizations of Ewens random permutations [PDF]

Discrete Mathematics & Theoretical Computer Science
An involution is a bijection that is its own inverse. Given a permutation $σ$ of $[n],$ let $\mathsf{invol}(σ)$ denote the number of ways $σ$ can be expressed as a composition of two involutions of $[n].$ We prove that the statistic $\mathsf{invol}$ is ...
Charles Burnette
doaj   +1 more source

Two-sided permutation statistics via symmetric functions

Forum of Mathematics, Sigma
Given a permutation statistic $\operatorname {\mathrm {st}}$ , define its inverse statistic $\operatorname {\mathrm {ist}}$ by . We give a general approach, based on the theory of symmetric functions, for finding the joint distribution of
Ira M. Gessel, Yan Zhuang
doaj   +1 more source

Pattern Avoidance in Weak Ascent Sequences [PDF]

Discrete Mathematics & Theoretical Computer Science
In this paper, we study pattern avoidance in weak ascent sequences, giving some results for patterns of length 3. This is an analogous study to one given by Duncan and Steingr\'imsson (2011) for ascent sequences. More precisely, we provide systematically
Beáta Bényi, Toufik Mansour, José L. Ramírez   +2 more
doaj   +1 more source

Alternating sign matrices with reflective symmetry and plane partitions: $n+3$ pairs of equivalent statistics and a Cauchy-type identity

Forum of Mathematics, Sigma
Vertically symmetric alternating sign matrices (VSASMs) of order $2n+1$ are known to be equinumerous with lozenge tilings of a hexagon with side lengths $2n+2,2n,2n+2,2n,2n+2,2n$ and a central triangular hole of size $2$ that exhibit
Ilse Fischer, Hans Höngesberg
doaj   +1 more source

On the $\operatorname{rix}$ statistic and valley-hopping [PDF]

Discrete Mathematics & Theoretical Computer Science
This paper studies the relationship between the modified Foata$\unicode{x2013}$Strehl action (a.k.a. valley-hopping)$\unicode{x2014}$a group action on permutations used to demonstrate the $\gamma$-positivity of the Eulerian polynomials$\unicode{x2014 ...
Nadia Lafrenière, Yan Zhuang
doaj   +1 more source

Finite automata, probabilistic method, and occurrence enumeration of a pattern in words and permutations. [PDF]

SIAM J Discret Math, 2020
Mansour T, Rastegar R, Roitershtein A.
europepmc   +1 more source