
Profile
Department
Natural Sciences, Mathematics Education
Position
Associate Professor
Academic Background
2004-2008, Kyushu University, Graduate School of Mathematics
2000-2004, Kyushu University, Faculty of Sciences, Department of Mathematics
Degree
Ph.D. (Mathematics), Kyushu University
Research Career
2009-2012, Tohoku University PD
2008-2009, Kyushu University PD
2006-2008, Kyushu University DC1
SDGs Related to Research

Research
Research Field
Algebraic Combinatorics
Keywords: Association scheme, Spectral graph theory, Codes and Design theory
Academic Paper
Embedding dimensions of matrices whose entries are indefinite distances in the pseudo-Euclidean space
Bulletin of the Iranian Mathematical Society, Springer, Vol. 50, No. 5, 2024Spherical designs and modular forms of the D4 lattice
Research in Number Theory, Springer, Vol. 9, No. 77, 2023Bounds for sets with few distances distinct modulo a prime ideal
Algebraic Combinatorics, Vol. 6, No. 2, pp. 539-545, 2023Rationality of the inner products of spherical s-distance t-designs for t ≥ 2s − 2, s ≥ 3
Linear Algebra and its Applications, Elsevier, Vol. 646, No. 1, pp. 107-118, 2022On the spectrum and linear programming bound for hypergraphs
European Journal of Combinatorics, Elsevier, Vol. 104, No. 103535, 2022A Proof of a Dodecahedron Conjecture for Distance Sets
Graphs and Combinatorics, Springer, Vol. 37, pp. 1585-1603, 2021Maximal 2-distance sets containing the regular simplex
Discrete math., Elsevier, Vol. 343, No. 11, 2020Largest regular multigraphs with three distinct eigenvalues
Discrete Math., Elsevier, Vol. 342, No. 7, pp. 2134-2138, 2019A spectral version of the Moore problem for bipartite regular graphs
Algebraic Combinatorics, Vol. 2, No. 6, pp. 1219-1238, 2019Complex spherical codes with three inner products
Discrete and Computational Geometry, Springer, Vol. 60, pp. 294-317, 2018On the largest subsets avoiding the diameter of (0,±1)-vectors
Ars Math. Contemp., Vol. 13, No. 1, pp. 1-13, 2017Maximal m-distance sets containing the representation of the Hamming graph H(n,m)
Discrete math., Elsevier, Vol. 340, No. 3, pp. 430-442, 2017Polynomial properties on large symmetric association schemes
Annals of Combinatorics, Springer, Vol. 20, pp. 379-386, 2016Maximizing the order of a regular graph of given valency and second eigenvalue
SIAM J. Discrete Math., Society for Industrial and Applied Mathematics, Vol. 30, No. 3, pp. 1509-1525, 2016Complex spherical codes with two inner products
European Journal of Combinatorics, Elsevier, Vol. 51, pp. 511-518, 2016Linear programming bounds for regular graphs
Graphs and Combinatorics, Springer, Vol. 31, pp. 1973-1984, 2015Weighing matrices and spherical codes
Journal of Algebraic Combinatorics, Springer, Vol. 42, No. 1, pp. 283-291, 2015A spectral equivalent condition of the P-polynomial property for association schemes
The Electronic Journal of Combinatorics, Vol. 21, No. 3, pp. 8, 2014Remarks on Hilbert identities, isometric embeddings, and invariant cubature
St. Petersburg Math. J., Vol. 25, No. 4, pp. 139-181, 2013Lower bounds for the minimum diameter of integral point sets
Australas. J. Combin, Combinatorial Mathematics Society of Australasia, Vol. 56, pp. 139-143, 2013 A characterization of Q-polynomial association schemes
J. Comb. Theory Ser. A, Elsevier, Vol. 119, No. 1, pp. 57-62, 2012A characterization of skew Hadamard matrices and doubly regular tournaments
Linear Algebra Appl., Elsevier, Vol. 437, No. 3, pp. 1050-1056, 2012A new approach for the existence problem of minimal cubature formulas based on the Larman-Rogers-Seidel theorem
SIAM J. Numer. Anal., Society for Industrial and Applied Mathematics, Vol. 50, No. 5, pp. 2716-2728, 2012A geometrical characterization of strongly regular graphs
Linear Algebra Appl., Elsevier, Vol. 437, No. 10, pp. 2587-2600, 2012Note on cubature formulae and designs obtained from group orbits
Canad. J. Math, Canadian Mathematical Society, Vol. 64, pp. 1359-1377, 2012A generalization of Larman-Rogers-Seidel's theorem
Discrete Math., Elsevier, Vol. 311, No. 10, pp. 792-799, 2011 Bounds on three- and higher-distance sets
European J. Combin., Elsevier, Vol. 32, No. 8, pp. 1182-1190, 2011 Bounds on s-distance sets with strength t
SIAM J. Discrete Math., Society for Industrial and Applied Mathematics, Vol. 25, pp. 1699-1713, 2011Inside s-inner product sets and Euclidean designs
Combinatorica, Springer, Vol. 31, No. 6, pp. 725-737, 2011On a generalization of distance sets
J. Comb. Theory Ser. A, Elsevier, Vol. 117, No. 7, pp. 810-826, 2010 A separation property of the zeros of Eisenstein series for SL(2,Z)
Bull. London Math. Soc., London Mathematical Society, Vol. 40, No. 1, pp. 26-36, 2008 On the rigidity of spherical t-designs that are orbits of reflection groups E8 and H4
European J. Combin., Elsevier, Vol. 29, No. 7, pp. 1696-1703, 2008 On the zeros of Eisenstein series for Γ0*(2) and Γ0*(3)
J. Math. Soc. Japan., Mathematical Society of Japan, Vol. 59, No. 3, pp. 693-706, 2007 A note on odd unimodular Euclidean lattices
Arch. Math., Springer, Vol. 86, No. 3, pp. 226-230, 2006 On the zeros of Eisenstein series associated with Γ0*(2) and Γ0*(3)
The Proceeding of Second COE Workshop on Sphere Packings, Kyushu University, pp. 131-135, 2005A note on odd unimodular Euclidean lattices
The Proceeding of Second COE Workshop on Sphere Packings, H. Nozaki, pp. 184-186, 2005