Results 81 to 90 of about 152 (126)

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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and [PDF]

, 2010
. A centrosymmetric permutation is one which is invariant under the reversecomplement operation, or equivalently one whose associated standard Young tableaux under the Robinson-Schensted algorithm are both invariant under the Schützenberger involution ...
Matteo Silimbani, Mark F. Flanagan
core  

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
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On Matrices with Bidimensional Fibonacci Numbers

Annales Mathematicae Silesianae
In this paper, the bidimensional extensions of the Fibonacci numbers are explored, along with a detailed examination of their properties, characteristics, and some identities.
Costa Eudes Antonio, Catarino Paula M.M.C.   +1 more
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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
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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
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Continued fractions using a Laguerre digraph interpretation of the Foata-Zeilberger bijection and its variants [PDF]

In the combinatorial theory of continued fractions, the Foata-Zeilberger bijection and its variants have been extensively used to derive various continued fractions enumerating several (sometimes infinitely many) simultaneous statistics on permutations ...
Deb, Bishal
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Subspace profiles over finite fields and q-Whittaker expansions of symmetric functions

Forum of Mathematics, Sigma
Bender, Coley, Robbins, and Rumsey posed the problem of counting the number of subspaces which have a given profile with respect to a linear endomorphism defined on a finite vector space.
Samrith Ram
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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

Combinatorics of rectangulations: old and new bijections [PDF]

A rectangulation is a decomposition of a rectangle into finitely many rectangles. Via natural equivalence relations, rectangulations can be seen as combinatorial objects with a rich structure, with links to lattice congruences, flip graphs, polytopes ...
Felsner, Stefan, Cardinal, Jean, Fusy, Éric, Asinowski, Andrei   +3 more
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