134 search results - page 18 / 27 » Combinatorics of diagrams of permutations |
COMBINATORICS
2006
13 years 9 months ago
2006
Let Sn be the group of permutations of [n] = {1, . . . , n}. The Bruhat order on Sn is a partial order relation, for which there are several equivalent definitions. Three well-kno...
COMBINATORICS
2002
13 years 9 months ago
2002
: We generalize the notion of pattern avoidance to arbitrary functions on ordered sets, and consider specifically three scenarios for permutations: linear, cyclic and hybrid, the f...
JCT
2010
13 years 8 months ago
2010
The pattern-avoiding fillings of Young diagrams we study arose from Postnikov’s work on positive Grassman cells. They are called Γ -diagrams, and are in bijection with decorate...
COMBINATORICS
2004
13 years 9 months ago
2004
A word is abelian square-free if it does not contain two adjacent subwords which are permutations of each other. Over an alphabet k on k letters, an abelian squarefree word is max...
COMBINATORICS
2000
13 years 9 months ago
2000
Given an integer n 2, and a non-negative integer k, consider all affine hyperplanes in Rn of the form xi = xj +r for i, j [n] and a non-negative integer r k. Let n,k be the pos...