COMBINATORICS
2007
13 years 4 months ago
2007
COMBINATORICS
2007
13 years 4 months ago
2007
A permutation class which is closed under pattern involvement may be described in terms of its basis. The wreath product construction X Y of two permutation classes X and Y is als...
COMBINATORICS
2007
13 years 4 months ago
2007
The density matrix of a graph is the combinatorial laplacian matrix of a graph normalized to have unit trace. In this paper we generalize the entanglement properties of mixed dens...
COMBINATORICS
2007
13 years 4 months ago
2007
In 1995, Hochberg, McDiarmid, and Saks proved that the vertex-bandwidth of the triangular grid Tn is precisely n + 1; more recently Balogh, Mubayi, and Pluh´ar posed the problem ...
COMBINATORICS
2007
13 years 4 months ago
2007
We study the shape of the Young diagram λ associated via the Robinson– Schensted–Knuth algorithm to a random permutation in Sn such that the length of the longest decreasing ...
COMBINATORICS
2007
13 years 4 months ago
2007
A k-ary necklace of order n is an equivalence class of strings of length n of symbols from {0, 1, . . . , k − 1} under cyclic rotation. In this paper we define an ordering on t...
COMBINATORICS
2007
13 years 4 months ago
2007
We use methods of combinatorics of polytopes together with geometrical and computational ones to obtain the complete list of compact hyperbolic Coxeter npolytopes with n + 3 facet...
COMBINATORICS
2007
13 years 4 months ago
2007
We present an infinite family of 3-connected non-bipartite graphs with chromatic roots in the interval (1, 2) thus resolving a conjecture of Jackson’s in the negative. In addit...
COMBINATORICS
2007
13 years 4 months ago
2007
COMBINATORICS
2007
13 years 4 months ago
2007
The distinguishing number ∆(X) of a graph X is the least positive integer n for which there exists a function f : V (X) → {0, 1, 2, · · · , n−1} such that no nonidentity ...