96 citations · 292 across the 62 of their papers we have counts for
4 papers · 1 filter
Complex Hadamard matrices contained in a Bose-Mesner algebra
Takuya Ikuta, Akihiro Munemasa
A complex Hadamard matrix is a square matrix H with complex entries of absolute value 1 satisfying , where stands for the Hermitian transpose and I is the identity ma…
Complementary Ramsey numbers and Ramsey graphs
Akihiro Munemasa, Masashi Shinohara
In this paper, we consider a variant of Ramsey numbers which we call complementary Ramsey numbers . We first establish their connections to pairs of Ramsey -…
On the smallest eigenvalues of the line graphs of some trees
Akihiro Munemasa, Yoshio Sano, Tetsuji Taniguchi
In this paper, we study the characteristic polynomials of the line graphs of generalized Bethe trees. We give an infinite family of such graphs sharing the same smallest eigenvalue…
Equiangular lines in Euclidean spaces
G. Greaves, J. H. Koolen, A. Munemasa +1
We obtain several new results contributing to the theory of real equiangular line systems. Among other things, we present a new general lower bound on the maximum number of equiang…