## YOSHINAGA, Masahiko

Position
Professor
Organization
Department of Mathematics
Research Interest
Algebraic Geometry, Topology, Combinatorics
Research Activities

Hyperplane arrangements relate several branches of mathematics, topology, representation theory, combinatorics, and so on. I am working in two aspects of hyperplane arrangements. The first is around logarithmic vector fields.
It is a reflexive sheaf on the projective space, which controls combinatorial structures of arrangements. The other is minimality of the homotopy types of the complements. Recently I am also interested in Ehrhart theory, Eulerian polynomials, and categorification of enumerative problems.

Papers:
[1] Characterization of a free arrangement and conjecture of Edelman and Reiner. Invent. Math. 157(2004), no. 2, 449-454.

[2] Hyperplane arrangements and Lefschetz’s hyperplane section theorem. Kodai Math. J. 30, no. 2 (2007), 157–194.

[3] Milnor fibers of real line arrangements. Journal of Singularities, vol 7 (2013), 220-237.

[4] Worpitzky partitions for root systems and characteristic quasi-polynomials. To appear in Tohoku Math. J.

Keywords
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WebPage
http://www.math.sci.hokudai.ac.jp/~yoshinaga/index.html