COMBINATORICS
2006
13 years 11 months ago
2006
COMBINATORICS
2006
13 years 11 months ago
2006
This paper introduces parity versions of familiar graph theoretic results, in particular results related to 2-connectedness. The even and odd circuit connected graphs are characte...
COMBINATORICS
2006
13 years 11 months ago
2006
Two sets are non-crossing if they are disjoint or one contains the other. The noncrossing graph NCn is the graph whose vertex set is the set of nonempty subsets of [n] = {1, . . ....
COMBINATORICS
2006
13 years 11 months ago
2006
Given an integer s 0 and a permutation Sn, let ,s be the graph on n vertices {1, . . . , n} where two vertices i < j are adjacent if the permutation flips their order and th...
COMBINATORICS
2006
13 years 11 months ago
2006
Let G be a group acting faithfully on a set X. The distinguishing number of the action of G on X, denoted DG(X), is the smallest number of colors such that there exists a coloring...
COMBINATORICS
2006
13 years 11 months ago
2006
COMBINATORICS
2006
13 years 11 months ago
2006
COMBINATORICS
2006
13 years 11 months ago
2006
We prove that the set of permutations generated by a stack of depth two and an infinite stack in series has a basis (defining set of forbidden patterns) consisting of 20 permutati...
COMBINATORICS
2006
13 years 11 months ago
2006
A homomorphism from an oriented graph G to an oriented graph H is a mapping from the set of vertices of G to the set of vertices of H such that -----(u)(v) is an arc in H whenever...
COMBINATORICS
2006
13 years 11 months ago
2006
We show that the Grothendieck bialgebra of the semi-tower of partition lattice algebras is isomorphic to the graded dual of the bialgebra of symmetric functions in noncommutative ...