492 search results - page 39 / 99 » combinatorics 2006 |
COMBINATORICS
2000
13 years 5 months ago
2000
We construct examples of nonnegative harmonic functions on certain graded graphs: the Young lattice and its generalizations. Such functions first emerged in harmonic analysis on th...
COMBINATORICS
2000
13 years 5 months ago
2000
We consider the problem of determining when two delta-matroids on the same ground-set have a common base. Our approach is to adapt the theory of matchings in 2-polymatroids develo...
COMBINATORICS
2000
13 years 5 months ago
2000
Recently Zagier proved a remarkable q-series identity. We show that this identity can also be proved by modifying Franklin's classical proof of Euler's pentagonal number...
COMBINATORICS
2000
13 years 5 months ago
2000
We give new lower bounds for the Schur numbers S(6) and S(7). This will imply new lower bounds for the Multicolor Ramsey Numbers R6(3) and R7(3). We also make several observations...
COMBINATORICS
2000
13 years 5 months ago
2000
The question of whether the characteristic polynomial of a simple graph is uniquely determined by the characteristic polynomials of its vertex-deleted subgraphs is one of the many...