EJC
2008
13 years 11 months ago
2008
We consider certain modules of the symmetric groups whose basis elements are called tabloids. As modules of the symmetric groups, some of these are isomorphic to Springer modules. ...
EJC
2008
13 years 11 months ago
2008
An arrangement of pseudocircles is a finite set of oriented closed Jordan curves each two of which cross each other in exactly two points. To describe the combinatorial structure ...
EJC
2010
13 years 11 months ago
2010
3 For d, k N with k 2d, let g(d, k) denote the infimum density of binary4 sequences (xi)iZ {0, 1}Z which satisfy the minimum degree condition d j=1 (xi+j +5
EJC
2010
13 years 11 months ago
2010
Let be a finite building (or, more generally, a thick spherical and locally finite building). The chamber graph G(), whose edges are the pairs of adjacent chambers in , is known t...
EJC
2010
13 years 11 months ago
2010
We prove that for any fixed r 2, the tree-width of graphs not containing Kr as a topological minor (resp. as a subgraph) is bounded by a linear (resp. polynomial) function of the...
EJC
2010
13 years 11 months ago
2010
Mutually unbiased bases (MUBs) in complex vector spaces play several important roles in quantum information theory. At present, even the most elementary questions concerning the m...
EJC
2010
13 years 11 months ago
2010
EJC
2010
13 years 11 months ago
2010
A Shilla distance-regular graph (say with valency k) is a distance-regular graph with diameter 3 such that its second largest eigenvalue equals to a3. We will show that a3 divide...
EJC
2010
13 years 11 months ago
2010
We study two enumeration problems for up-down alternating trees, i.e., rooted labelled trees T, where the labels v1, v2, v3, . . . on every path starting at the root of T satisfy v...
EJC
2010
13 years 11 months ago
2010
We start by describing all the varieties of loops Q that can be defined by autotopisms x, x Q, where x is a composition of two triples, each of which becomes an autotopism when th...