Results 1 to 10 of about 56,648 (187)

Bijections on m-level Rook Placements [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2014
Partition the rows of a board into sets of $m$ rows called levels. An $m$-level rook placement is a subset of squares of the board with no two in the same column or the same level.
Kenneth Barrese, Bruce Sagan
doaj   +3 more sources

q-Rook placements and Jordan forms of upper-triangular nilpotent matrices [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2013
The set of $n$ by $n$ upper-triangular nilpotent matrices with entries in a finite field $F_q$ has Jordan canonical forms indexed by partitions $λ \vdash n$. We study a connection between these matrices and non-attacking q-rook placements, which leads to
Martha Yip
doaj   +3 more sources

Patterns in matchings and rook placements [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2013
Extending the notion of pattern avoidance in permutations, we study matchings and set partitions whose arc diagram representation avoids a given configuration of three arcs.
Jonathan Bloom, Sergi Elizalde
doaj   +3 more sources

Matrix Ansatz, lattice paths and rook placements [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2009
We give two combinatorial interpretations of the Matrix Ansatz of the PASEP in terms of lattice paths and rook placements. This gives two (mostly) combinatorial proofs of a new enumeration formula for the partition function of the PASEP.
S. Corteel   +3 more
doaj   +3 more sources

Combinatorics of diagrams of permutations [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2014
There are numerous combinatorial objects associated to a Grassmannian permutation $w_λ$ that index cells of the totally nonnegative Grassmannian. We study some of these objects (rook placements, acyclic orientations, various restricted fillings) and ...
Joel Brewster Lewis, Alejandro Morales
doaj   +1 more source

On the Spectra of Simplicial Rook Graphs [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2013
The $\textit{simplicial rook graph}$ $SR(d,n)$ is the graph whose vertices are the lattice points in the $n$th dilate of the standard simplex in $\mathbb{R}^d$, with two vertices adjacent if they differ in exactly two coordinates.
Jeremy L. Martin, Jennifer D. Wagner
doaj   +1 more source

A Combinatorial Model for $q$-Generalized Stirling and Bell Numbers [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2008
We describe a combinatorial model for the $q$-analogs of the generalized Stirling numbers in terms of bugs and colonies. Using both algebraic and combinatorial methods, we derive explicit formulas, recursions and generating functions for these $q ...
Miguel Méndez, Adolfo Rodríguez
doaj   +1 more source

Stammering tableaux [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2017
The PASEP (Partially Asymmetric Simple Exclusion Process) is a probabilistic model of moving particles, which is of great interest in combinatorics, since it appeared that its partition function counts some tableaux.
Matthieu Josuat-Vergès
doaj   +1 more source

Modified Growth Diagrams, Permutation Pivots, and the BWX Map $\phi^*$ [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2012
In their paper on Wilf-equivalence for singleton classes, Backelin, West, and Xin introduced a transformation $\phi^*$, defined by an iterative process and operating on (all) full rook placements on Ferrers boards. Bousquet-Mélou and Steingrimsson proved
Jonathan Bloom, Dan Saracino
doaj   +1 more source

Type B (p, q)-Stirling Numbers via Signed Restricted Growth Functions and Rook Theory

open access: yesMathematics
Stirling numbers are among the most classical objects in enumerative combinatorics, counting set partitions and permutations. In this paper, we study their (p,q)-analogues in type B from a rook-theoretic point of view. We introduce a type B Ferrers board
Hasan Arslan   +3 more
doaj   +1 more source

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