Mathematical Journal of Okayama University volume64 issue1
Tokyo Metropolitan College of Industrial Technology
We have the best constants of three kinds of discrete Sobolev inequalities on the complete bipartite graph with 2N vertices, that is, KN,N. We introduce a discrete Laplacian A on KN,N. A is a 2N ×2N real symmetric positive-semidefinite matrix whose eigenvector corresponding to zero eigenvalue is 1 = t(1, 1, … , 1)∈ C2N. A discrete heat kernel, a Green’s matrix and a pseudo Green’s matrix play important roles in giving the best constants.
Discrete Sobolev inequality
Mathematics Subject Classification. Primary 46E39; Secondary 35K08.