1215 search results - page 119 / 243 » Combinatorics |
127
Voted
COMBINATORICS
2007
15 years 3 months ago
2007
Let µ (G) and µmin (G) be the largest and smallest eigenvalues of the adjacency matrix of a graph G. Our main results are: (i) If H is a proper subgraph of a connected graph G o...
108
Voted
COMBINATORICS
2007
15 years 3 months ago
2007
By introducing the notion of relative derangements of type B, also called signed relative derangements, which are defined in terms of signed permutations, we obtain a type B anal...
109
Voted
COMBINATORICS
2007
15 years 3 months ago
2007
Let Sn denote the symmetric group on [n] = {1, . . . , n}. A family I ⊆ Sn is intersecting if any two elements of I have at least one common entry. It is known that the only int...
96
Voted
COMBINATORICS
2007
15 years 3 months ago
2007
We define an excedance number for the multi-colored permutation group i.e. the wreath product (Zr1 × · · · × Zrk ) Sn and calculate its multi-distribution with some natural ...
123
click to vote
COMBINATORICS
2007
15 years 3 months ago
2007
Sommerville and Davies classified the spherical triangles that can tile the sphere in an edge-to-edge fashion. However, if the edge-to-edge restriction is relaxed, there are othe...