Tatsuya Ohshita

J-GLOBAL         Last updated: Mar 25, 2019 at 16:20
 
Avatar
Name
Tatsuya Ohshita
Affiliation
Ehime University
Section
Graduate School of Science and Engineering Mathematics,Physics,and Earth Sciences

Research Areas

 
 
  • Mathematics / Algebra / number theory

Academic & Professional Experience

 
Apr 2013
 - 
Jul 2014
Kyoto University 
 

Published Papers

 
Yasuhiro Ishitsuka, Tetsushi Ito, Tatsuya Ohshita
JSIAM Letters   11 9-12   Mar 2019   [Refereed]
We give two algorithms to compute linear determinantal representations of
smooth plane curves of any degree over any field. As particular examples, we
explicitly give representatives of all equivalence classes of linear
determinantal representatio...
Tatsuya Ohshita
to appear(accepted)    [Refereed]
In this article, we study the monoid of fractional ideals and the ideal class
semigroup of an arbitrary given one dimensional normal domain O obtained by an
infinite integral extension of a Dedekind domain. We introduce a notion of
"upper semicont...
Tatsuya Ohshita
JOURNAL OF NUMBER THEORY   135 67-138   Feb 2014   [Refereed]
Higher Fitting ideals of Iwasawa modules and Euler systems
Tatsuya Ohshita
RIMS Kokyuroku Bessatsu   B51 139-150   2014   [Refereed]
Tatsuya Ohshita
Kyoto Journal of Mathematics   53(4) 845-887   2013   [Refereed]
On Higher Fitting Ideals of Certain Iwasawa Modules Associated with Galois Representations and Euler Systems
Tatsuya Ohshita
Kyoto Journal of Mathematics   to appear(accepted)    [Refereed]

Misc

 
Tatsuya Ohshita
   May 2018
Let T be a free Z_p-module of finite rank equipped with a continuous
Z_p-linear action of the absolute Galois group of a number field K satisfying
certain conditions. In this article, by using a Selmer group corresponding to
T, we give a lower bou...
Yasuhiro Ishitsuka, Tetsushi Ito, Tatsuya Ohshita
   Apr 2018
We use explicit methods to study the 4-torsion points on the Jacobian variety
of the Fermat quartic. With the aid of computer algebra systems, we explicitly
give a basis of the group of 4-torsion points. We calculate the Galois action,
and show th...
Tatsuya Ohshita
   Dec 2017
In this article, we study the pseudo-isomorphism class of the dual fine
Selmer group Tex attached to a Tex-adic Galois deformation whose deformation
ring Tex is isomorphic to the ring of formal power series. By using the
"Kolyvagin system" a...
Tatsuya Ohshita
   Oct 2017
In our previous work, by using Kolyvagin derivatives of elliptic units, we
constructed ideals C_i of the Iwasawa algebra, and proved that the ideals C_i
become "upper bounds" of the higher Fitting ideals of the one and two variable
p-adic unramifi...

Conference Activities & Talks

 
Euler systems for Galois deformations and pseudo-isomorphism classes of the dual fine Selmer groups
Tatsuya Ohshita
Mar 2015   
Euler systems for Galois deformations and higher Fitting ideals of the dual fine Selmer groups
Tatsuya Ohshita
14 Nov 2014   

Others

 
Nov 2017   Arithmetic Geometry and Related Topics