J-GLOBAL         Last updated: Dec 10, 2019 at 12:55
Nagaoka National College of Technology
Division of General Education
Job title
Doctor (Science)(Niigata University), Master (Science)(Niigata University)
Research funding number

Research Interests


Research Areas


Academic & Professional Experience

Faculty of Engineering,Niigata University, part-time lecturer


Information Science and Engineering, Graduate School, Division of National Science and Technology, Niigata University
Mathematics, Faculty of Science, Niigata University
Electrical Engineering, Nagaoka National College of Technology

Published Papers

Log del Pezzo surfaces of rank one containing the affine plane
Hideo Kojima and Takeshi Takahashi
Nihonkai Mathematical Journal   29(2) 77-130   2018   [Refereed]
Jiryo Komeda, Takeshi Takahashi
Journal of the Korean Mathematical Society   54 69-86   Jan 2017   [Refereed]
© 2017 Korean Mathematical Society. The point P ∈ P2is referred to as a Galois point for a non-singular plane algebraic curve C if the projection ΠP: C {long rightwards arrow} ℙ1from P is a Galois covering. In contrast, the point P’ ∈ C’ is referr...
GOTO Jun, SHOBUGAWA Yugo, KAWANO Yoh, AMAYA Yoshihiro, IZUMIKAWA Takuji, KATSURAGI Yoshinori, SHIIYA Tomohiro, SUZUKI Tsubasa, TAKAHASHI Takeshi, TAKAHASHI Toshihiro, YOSHIDA Hidenori, NAITO Makoto
JPS Conference Proceedings (Web)   11 ROMBUNNO.070007 (WEB ONLY)   Nov 2016   [Refereed]
T. Takahashi, T. Takahashi
Rendiconti del Seminario Matematico dell 'Universita' di Padova/Mathematical Journal of the University of Padova   135 39-61   Jan 2016   [Refereed]
© 2016, Universita di Padova. All rights reserved. Let C be a nonsingular plane quintic curve over the complex number field ℂ, and let πp: C→ℙ1 be a projection from P Є C. Let LP be the Galois closure of the field extension ℂ(C)/ℂ(ℙ1) induced by π...
Satoru Fukasawa, Takeshi Takahashi
Transactions of the American Mathematical Society   366 1639-1658   Jan 2014   [Refereed]
A Galois point for a hypersurface is a point from which the projection induces a Galois extension of function fields. The purpose of this article is to determine the set Δ(X) of Galois points for a hypersurface X with dim Sing(X) ≤ dim X - 2 in ch...
Hideo Kojima, Takeshi Takahashi
Journal of Algebra   360 53-70   Jun 2012   [Refereed]
We study normal del Pezzo surfaces of rank one with only log canonical singularities. Under some additional assumptions, we classify such surfaces. Moreover, we prove that every normal del Pezzo surface of rank one with only rational log canonical...
Takeshi Takahashi
Journal of Pure and Applied Algebra   216 12-19   Jan 2012   [Refereed]
Let Π:Xe→P1 (e≥0) be the rational ruled complex surface defined by OP1⊕OP1(-e) on P1, i.e., the eth Hirzebruch surface. Let C be a nonsingular projective curve on Xe, and π:C→P1 the restriction of Π to C. We assume that C is not rational nor ellip...
Kei Miura, Akira Ohbuchi, Takeshi Takahashi
Far East Journal of Mathematical Sciences   47 109-119   Dec 2010   [Refereed]
Let S be a complex projective surface obtained from a Hirzebruch surface by one monoidal transformation, and C be a nonsingular curve on S. We prove that if the nonsingular pair (S, C) is relatively minimal, then every automorphism of C can be ext...
Hideo Kojima, Takeshi Takahashi
Annali di Matematica Pura ed Applicata   188 153-169   Jan 2009   [Refereed]
In this paper, we consider the minimal compactifications X of the complex affine plane with at most log canonical singular points. We classify the surfaces X in the case X has at least one non-log terminal singular point.
Hideo Kojima, Takeshi Takahashi
Tokyo Journal of Mathematics   29 301-317   Jan 2006   [Refereed]


Jiryo Komeda, Takeshi Takahashi
   Mar 2017
We investigate the number of Galois Weierstrass points whose Weierstrass
semigroups are generated by two positive integers.
Satoru Fukasawa, Kei Miura, Takeshi Takahashi
   May 2015
We introduce the new notion of the "quasi-Galois point" in Algebraic
geometry, which is a generalization of the Galois point. A point Tex in
projective plane is said to be quasi-Galois for a plane curve if the curve
admits a non-trivial birational...
The group generated by automorphisms belonging to Galois points of the quartic surface (jointly worked)
Nihonkai Mathematical Journal   12(1) 89-99   2001

Conference Activities & Talks

Development of an application for rough estimation of individual doses Purpose, Plan and What we did in the first six months
Takeshi Takahashi, Jun Goto, Tatsuya Kondo, Masahiro Sugawa, Naoki Kano, Hiroko Yoshida, Ken Ohno, Yusuke Oribe, Hidenori Yoshida
11 Sep 2019   
Weak Galois-Weierstrass points with semigroups generated by two integers [Invited]
6 Oct 2018   
Weak Galois Weierstrass points whose semigroups are generated by two integers [Invited]
8 Sep 2017   
Development of a Portable Gamma-ray Survey System for the Measurement of Dose Rates in Air
Goto J, Shobugawa Y, Kawano Y, Amaya Y, Izumikawa T, Katsuragi Y, Shiiya T, Suzuki T, Takahashi TA, Takahashi TO, Yoshida H, Naito M
International Symposium on Radiation Detectors and Their Uses (ISRD2016)   19 Jan 2016   Organized by High Energy Accelerator Research Organization(KEK), JSPS 186th Committee on Radiation Science and Its Applications

Research Grants & Projects

Studies on geometric and algebraic structures of algebraic varieties
Project Year: 2000   
Structure of Open Algebraic Surfaces
Project Year: 2003