COMBINATORICS
2006
14 years 6 months ago
2006
COMBINATORICS
2006
14 years 6 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
14 years 6 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
14 years 6 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
14 years 6 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
14 years 6 months ago
2006
COMBINATORICS
2006
14 years 6 months ago
2006
COMBINATORICS
2006
14 years 6 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
14 years 6 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
14 years 6 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 ...