Research Activities

Preprints arXiv / Front for the arXiv

(with Ming-chang Kang, Aiichi Yamasaki) An application of cohomological invariants, 11 pages. arXiv:1903.03750
(with Aiichi Yamasaki) Birational classification for algebraic tori, 175 pages. arXiv:2112.02280 / Algorithm
(with Kazuki Kanai, Aiichi Yamasaki) Hasse norm principle for $M_{11}$ and $J_1$ extensions, 17 pages. arXiv:2210.09119 / Algorithm
(with Aiichi Yamasaki) Rationality problem for norm one tori for $A_5$ and $PSL_2(F_8)$ extensions, 23 pages. arXiv:2309.16187 / Algorithm
(with Kazuki Kanai, Aiichi Yamasaki) Norm one tori and Hasse norm principle, III: Degree 16 case, 74 pages. arXiv:2404.01362 / Algorithm

Papers MathSciNet / zbMATH

(with Hidetaka Kitayama) Rationality problem of two-dimensional quasi-monomial group actions,
To appear in Transformation Groups, 36 pages. Springer Preprint version: arXiv:2012.12046
(with Aiichi Yamasaki) Rationality problem for norm one tori for dihedral extensions,
Journal of Algebra 640 (2024/2) 368-384. ScienceDirect
(with Ming-chang Kang, Aiichi Yamasaki) Multiplicative Invariant Fields of Dimension ≤ 6,
Memoirs of the American Mathematical Society 283 (2023/3), no. 1403, vi+137 pp. AMS Bookstore / Algorithm
(with Kazuki Kanai, Aiichi Yamasaki) Norm one tori and Hasse norm principle, II: Degree 12 case,
Journal of Number Theory 244 (2023/3) 84-110. ScienceDirect Extended version: arXiv:2003.08253 / Algorithm
(with Kazuki Kanai) Davenport and Hasse's theorems and lifts of multiplication matrices of Gaussian periods,
Finite Fields and their Applications 84 (2022/12) Paper No. 102101, 26 pp. ScienceDirect Extended version: arXiv:2105.14872
(with Kazuki Kanai, Aiichi Yamasaki) Norm one tori and Hasse norm principle,
Mathematics of Computation 91 (2022/9) 2431-2458. AMS Extended version: arXiv:1910.01469 / Algorithm
(with Ming-chang Kang, Hidetaka Kitayama, Aiichi Yamasaki) A two-dimensional rationality problem and intersections of two quadrics,
Manuscripta Mathematica 168 (2022/7) 423-437. Springer
(with Aiichi Yamasaki) Rationality problem for norm one tori,
Israel Journal of Mathematics 241 (2021/3), no. 2, 849-867. Springer Extended version: arXiv:1811.01676 / Algorithm
(with Masakazu Koshiba) On Lecacheux's family of quintic polynomials,
Proceedings of the Japan Academy, Series A 97 (2021/1), no. 1, 1-6. Project Euclid Extended version: arXiv:2003.13458
(with Hidetaka Kitayama) Three-dimensional purely quasimonomial actions,
Kyoto Journal of Mathematics 60 (2020/4), no. 1, 335-377. Project Euclid
(with Sumito Hasegawa, Aiichi Yamasaki) Rationality problem for norm one tori in small dimensions,
Mathematics of Computation 89 (2020/3), no. 322, 923-940. AMS Extended version: arXiv:1811.02145 / Algorithm
(with Ming-chang Kang, Aiichi Yamasaki) Degree three unramified cohomology groups and Noether's problem for groups of order 243,
Journal of Algebra 544 (2020/2), 262-301. ScienceDirect Extended version: arXiv:1710.01958 / Algorithm
(with Ming-chang Kang, Aiichi Yamasaki) Rationality problems for relation modules of dihedral groups,
Journal of Algebra 530 (2019/7), 368-401. ScienceDirect Old version: Class numbers and algebraic tori. arXiv:1312.6738
(with Aiichi Yamasaki) Rationality problem for algebraic tori,
Memoirs of the American Mathematical Society 248 (2017/7), no. 1176, v+215 pp. AMS Bookstore / Algorithm
Complete solutions to a family of Thue equations of degree 12,
Journal de Théorie des Nombres de Bordeaux 29 (2017/7), 549-568. JTNB
(with Ming-chang Kang, Aiichi Yamasaki) Degree three unramified cohomology groups,
Journal of Algebra 458 (2016/7), 120-133. ScienceDirect
Birational classification of fields of invariants for groups of order 128,
Journal of Algebra 445 (2016/1), 394-432. ScienceDirect
(with Huah Chu, Shou-Jen Hu, Ming-chang Kang) Noether's problem for groups of order 243,
Journal of Algebra 442 (2015/11), 233-259. ScienceDirect
On Noether's problem for cyclic groups of prime order,
Proceedings of the Japan Academy, Series A 91 (2015/3), no. 3, 39-44. Project Euclid Extended version: arXiv:1402.3678
On the simplest quartic fields and related Thue equations,
Computer Mathematics, Springer, 67-85, 2014/10. Springer
(with Ming-chang Kang, Hidetaka Kitayama) Quasi-monomial actions and some 4-dimensional rationality problems,
Journal of Algebra 403 (2014/2), 363-400. ScienceDirect
(with Ming-chang Kang, Boris E. Kunyavskii) Noether's problem and unramified Brauer groups,
Asian Journal of Mathematics 17 (2013/12), no. 4, 689-714. International Press Old version: Unramified Brauer groups for groups of order p^5 arXiv:1109.2966
On the simplest sextic fields and related Thue equations,
Functiones et Approximatio, Commentarii Mathematici 47 (2012/9), no. 1, 35-49. Project Euclid
On correspondence between solutions of a family of cubic Thue equations and isomorphism classes of the simplest cubic fields,
Journal of Number Theory 131 (2011/11), no. 11, 2135-2150. ScienceDirect
(with Hidetaka Kitayama, Aiichi Yamasaki) Rationality problem of three-dimensional monomial group actions,
Journal of Algebra 341 (2011/9), no. 1, 45-108. ScienceDirect
(with Ming-chang Kang) Twisted symmetric group actions,
Pacific Journal of Mathematics 248 (2010/12), no. 2, 285-304. Pacific J. Math.
(with Katsuya Miyake) On the field intersection problem of solvable quintic generic polynomials,
International Journal of Number Theory 6 (2010/8), no. 5, 1047-1081. World Scientific
(with Katsuya Miyake) A note on the field isomorphism problem of X^3+sX+s and related cubic Thue equations,
Interdisciplinary Information Sciences 16 (2010/3), no. 1, 45-54.
Special Section: Japan-Korea Joint Seminar on Number Theory and Related Topics 2008. J-STAGE
(with Katsuya Miyake) On the field intersection problem of quartic generic polynomials via formal Tschirnhausen transformation,
Commentarii Mathematici Universitatis Sancti Pauli 58 (2009/7), no. 1, 51-86. Rikkyo Roots
(with Katsuya Miyake) A geometric framework for the subfield problem of generic polynomials via Tschirnhausen transformation,
Number theory and applications, 65-104, Proceedings of the International Conferences on Number Theory and Cryptography
held in Allahabad, December 2006 and February 2007. Edited by S. D. Adhikari and B. Ramakrishnan.
Hindustan Book Agency, New Delhi, 2009/3. AMS Springer Preprint version: arXiv:0710.0287
(with Ming-chang Kang) A rationality problem of some Cremona transformation,
Proceedings of the Japan Academy, Series A 84 (2008/10), no. 8, 133-137. Project Euclid
(with Yuichi Rikuna) Rationality problem of three-dimensional purely monomial group actions: the last case,
Mathematics of Computation 77 (2008/7), no. 263, 1823-1829. AMS
(with Ki-ichiro Hashimoto and Yuichi Rikuna) Noether's problem and Q-generic polynomials for the normalizer of the 8-cycle in S₈ and its subgroups,
Mathematics of Computation 77 (2008/4), no. 262, 1153-1183. AMS
(with Katsuya Miyake) Tschirnhausen transformation of a cubic generic polynomial and a 2-dimensional involutive Cremona transformation,
Proceedings of the Japan Academy, Series A 83 (2007/3), no. 3, 21-26. Project Euclid
Explicit lifts of quintic Jacobi sums and period polynomials for F_q,
Proceedings of the Japan Academy, Series A 82 (2006/9), no. 7, 87-92. Project Euclid
(with Ki-ichiro Hashimoto) Families of cyclic polynomials obtained from geometric generalization of Gaussian period relations,
Mathematics of Computation 74 (2005/7), no. 251, 1519-1530. AMS
(with Ki-ichiro Hashimoto) Geometric generalization of Gaussian period relations with application to Noether's problem for meta-cyclic groups,
Tokyo Journal of Mathematics 28 (2005/6), no. 1, 13-32. Project Euclid
Noether's problem for some meta-abelian groups of small degree,
Proceedings of the Japan Academy, Series A 81 (2005/1), no. 1, 1-6. Project Euclid
Multiplicative quadratic forms on algebraic varieties,
Proceedings of the Japan Academy, Series A 79 (2003/4), no. 4, 71-75. Project Euclid

Ph.D. Dissertation

Multiplicative quadratic forms on algebraic varieties and Noether's problem for meta-abelian groups,
Waseda University, March 2005. Waseda University

Refereed Articles & Surveys

Noether's problem and rationality problem for multiplicative invariant fields: a survey,
Algebraic number theory and related topics 2016, 29-53, RIMS Kôkyûroku Bessatsu B77,
Res. Inst. Math. Sci. (RIMS), Kyoto, (2020/4). Kyoto / RIMS
Rationality problem for quasi-monomial actions,
Algebraic number theory and related topics 2012, 203-227, RIMS Kôkyûroku Bessatsu B51,
Res. Inst. Math. Sci. (RIMS), Kyoto, (2014/10). Kyoto / RIMS
(with Katsuya Miyake) Some Diophantine problems arising from the isomorphism problem of generic polynomials,
Number Theory: Dreaming in Dreams, 87-105, Proceedings of the 5th China-Japan Seminar.
Edited by T. Aoki, S. Kanemitsu and J. Liu, World Sci. Publ., Singapore, 2009/11. World Scientific
(with Katsuya Miyake) On the field intersection problem of generic polynomials: a survey,
Algebraic number theory and related topics 2007, 231-247, RIMS Kôkyûroku Bessatsu B12,
Res. Inst. Math. Sci. (RIMS), Kyoto, (2009/8). Kyoto / RIMS

Books

田中環，小島秀雄，星明考，折田龍馬，印南信宏，吉原久夫，要点明解線形数学三訂版，培風館，2022年4月，203ページ．培風館
星明考，群論序説，日本評論社，2016年3月，271ページ．日本評論社
印南信宏，田中環，小島秀雄，星明考，要点明解線形数学改訂版，培風館，2016年2月，178ページ．培風館

Visits & Attendances

2023	Dec.	(3 days)	Yufuin Workshop on Algebraic Geometry, Nippon Bunri University, Japan Google
2023	Dec.	(1 week)	Algebraic Number Theory and Related Topics 2023, RIMS, Kyoto University, Japan RIMS
2023	Dec.	(3 days)	Niigata Algebra Symposium, Niigata University, Japan Niigata
2023	Oct.	(1 week)	Kinosaki algebraic geometry symposium 2023, Kinosaki International Arts Center, Japan WordPress
2023	Oct.	(1 week)	International workshop on Birational Geometry, Nagoya Univeristy, Japan WordPress
2023	Sep.	(1 week)	MFO-RIMS Tandem workshop 2023 - Arithmetic Homotopy and Galois Theory, RIMS, Kyoto Univeristy, Japan AHGT IRN
2023	Sep.	(1 day)	Number theory joint seminar, Department of Mathematics, Kyoto Univeristy, Japan Kyoto
2023	Aug.	(4 days)	The 68th Algebra Symposium, Nagoya University, Japan MSJ
2023	Mar.	(1 week)	Arithmetic & Homotopic Galois Theory 2023, RIMS, Kyoto Univeristy, Japan AHGT IRN
2023	Feb.	(2 days)	Yufuin Workshop on Algebraic Geometry, Nippon Bunri University, Japan Google
2022	Nov.	(1 week)	Rationality, Moduli Spaces, and Related Topics, Nagoya University, Japan WordPress
2021	Mar.	(1 week)	Homotopic and Geometric Galois Theory, Zoom (Oberwolfach, Germany) MFO
2021	Feb.	(1 day)	Special lectures. In honor of Professor Shigefumi Mori's 70th Birthday, Zoom (Kyoto, Japan)
2021	Feb.	(3 days)	Degenerations and models of algebraic varieties and related topics, Zoom (Kobe, Japan) Google
2019	Nov.	(1 week)	The 41st Symposium on Commutative Algebra, Kurashiki Seaside Hotel, Japan Google
2019	Oct.	(1 week)	Kinosaki algebraic geometry symposium 2019, Kinosaki International Arts Center, Japan
2019	Sep.	(2 weeks)	National Center for Theoretical Sciences (NCTS), National Taiwan University, Taiwan NTU
2019	Sep.	(1 week)	The 27th Summer School on Number Theory, Tohoku University of Community Service and Science, Koeki Hall, Japan Google
2019	Aug.	(3 weeks)	National Center for Theoretical Sciences (NCTS), National Taiwan University, Taiwan NTU
2018	Mar.	(1 week)	Algebraic Geometry and Moduli Theory, Conference in Honor of Shigeru Mukai's Retirement, RIMS, Kyoto Univeristy, Japan Nagoya
2018	Jun.	(1 week)	Université Pierre-et-Marie-Curie (Paris VI) et Université Paris-Sud, Paris, Orsay, France
2018	Jun.	(1 day)	Séminaire N. Bourbaki, Institut Henri Poincaré, Paris, France ENS
2018	Jun.	(2 days)	International Workshop on Algebra, National Center for Theoretical Sciences (NCTS), National Taiwan University, Taiwan NTU
2018	May	(3 days)	Profinite monodromy, Galois representations, and Complex functions, In honor of Professor Yasutaka Ihara's 80th Birthday, RIMS, Kyoto University, Japan RIMS
2018	Mar.	(1 week)	Motives in Tokyo, on the occasion of Shuji Saito's 60th Birthday, The University of Tokyo, Japan Chiba
2017	Dec.	(1 week)	Algebraic Number Theory and Related Topics 2017, RIMS, Kyoto University, Japan RIMS
2017	Oct.	(1 week)	Kinosaki algebraic geometry symposium 2017, Kinosaki International Arts Center, Japan Google
2017	Sep.	(1 week)	Workshop on p-adic L-functions and algebraic cycles, National Taiwan University, Taiwan NTU
2017	Aug.	(6 weeks)	National Center for Theoretical Sciences (NCTS), National Taiwan University, Taiwan NTU
2017	Jul.	(1 week)	Iwasawa 2017, The University of Tokyo, Japan Tokyo
2017	Jun.	(3 days)	Journées Algophantiennes Bordelaises 2017, Institut de Mathématiques de Bordeaux, Université Bordeaux, France Bordeaux
2016	Nov.	(1 week)	Algebraic Number Theory and Related Topics 2016, RIMS, Kyoto University, Japan RIMS
2016	Oct.	(3 days)	Researches on isometries from various viewpoints, RIMS, Kyoto University, Japan
2016	Sep.	(1 week)	Japan-Taiwan Joint Conference on Number Theory 2016, National Taiwan University, Taiwan NTU
2016	Aug.	(7 weeks)	National Center for Theoretical Sciences (NCTS), National Taiwan University, Taiwan NTU
2016	Jul.	(1 week)	Rationality and self-maps of algebraic varieties, RIMS, Kyoto University, Japan RIMS
2015	Sep.	(3 days)	New developments and progress in mathematics via computer algebra system, RIMS, Kyoto University, Japan Kanazawa
2015	Sep.	(3 days)	The 4th International Congress on Natural Sciences (ICNS2015), National Changhua University of Education, Taiwan NCUE
2015	Aug.	(4 weeks)	National Center for Theoretical Sciences (NCTS), National Taiwan University, Taiwan NTU
2015	Jul.	(2 days)	Kálmán Győry 75 Symposium, University of Debrecen, Hungary Győry 75
2015	Jul.	(1 week)	29th Journées Arithmétiques (JA2015), University of Debrecen, Hungary JA2015
2015	Mar.	(1 week)	Joint Seminar and Reseach Camp (JSRC2015)，Niigata University, Japan JSRC2015
2014	Dec.	(1 week)	National Center for Theoretical Sciences (NCTS) Taipei Office, National Taiwan University, Taiwan NTU
2014	Sep.	(1 week)	New Developments in Algebraic Geometry, National Taiwan University, Taiwan NTU
2014	Aug.	(4 weeks)	National Center for Theoretical Sciences (NCTS) Taipei Office, National Taiwan University, Taiwan NTU
2014	Aug.	(2 weeks)	SEOUL ICM 2014, Coex, Seoul, Korea SEOUL ICM 2014
2014	Jul.	(1 week)	Kyoto Workshop on Algebraic Varieties and Automorphism Groups, RIMS, Kyoto University, Japan Niigata
2013	Oct.	(3 days)	The 3rd International Congress on Natural Sciences with Sisterhood Universities (ICNS2013), Niigata University, Japan ICNS2013
2013	Sep.	(1 day)	Nishi-Waseda Seminar on Number Theory, In honor of Professor Shizuo Endo's 80th Birthday, Waseda University, Japan
2013	Sep.	(1 week)	Thue 150, Institut de Mathématiques de Bordeaux, Université Bordeaux 1, France Thue 150
2013	Aug.	(3 weeks)	National Center for Theoretical Sciences (NCTS) Taipei Office, National Taiwan University, Taiwan NTU
2012	Dec.	(1 week)	Algebraic Number Theory and Related Topics, RIMS, Kyoto University, Japan Tokyo
2012	Aug.	(3 weeks)	National Center for Theoretical Sciences (NCTS) Taipei Office, National Taiwan University, Taiwan NTU
2011	Aug.	(5 weeks)	National Center for Theoretical Sciences (NCTS) Taipei Office, National Taiwan University, Taiwan NTU
2010	Oct.	(3 weeks)	Taida Institute for Mathematical Sciences (TIMS), National Taiwan University, Taiwan TIMS
2009	Dec.	(1 week)	The Joint Conference of ASCM2009 and MACIS2009, JAL Resort Sea Hawk Hotel Fukuoka, Japan Kyushu
2008	Nov.	(1 week)	The Japan-Korea Joint Seminar on Number Theory and Related Topics 2008, Tohoku University, Japan Tohoku
2008	Aug.	(1 week)	The 5th Japan-China Seminar on Number Theory, Kinki University, Japan World Scientific
2008	Jun.	(1 week)	Foundations of Computational Mathematics, City University of Hong Kong, China FoCM'08
2007	Dec.	(1 week)	Algebraic Number Theory and Related Topics, RIMS, Kyoto University, Japan Osaka
2007	Jul.	(2 weeks)	National Center for Theoretical Sciences (NCTS) Taipei Office, National Taiwan University, Taiwan NTU
2007	Jun.	(1 week)	National Center for Theoretical Sciences (NCTS), Math. Division, National Tsing Hua University, Taiwan NCTS
2006	Dec.	(1 week)	International Conference on Number Theory, Harish-Chandra Research Institute (HRI), India HRI
2005	Sep	(1 week)	Galois groups and algebraic equations, Kagoshima University, Japan UEC
2005	Jul.	(1 day)	Vortrag in der Arbeitsgemeinschaft über Algebra, Technische Universität München, Germany
2005	May	(1 day)	Oberseminar Algebra-Zahlentheorie, Ruprecht-Karls-Universität Heidelberg, Germany
2005	May	(1 day)	Kolloquium in Universität des Saarlandes, Universität des Saarlandes Germany, Saarlandes
2004	Sep.	(1 year)	Laboratory of Prof. Manfred Knebusch, Regensburg University, Germany Regensburg

2023.8.28	新潟大学　学術出版奨励賞 Niigata
2021.12.24	新潟大学　優秀論文表彰 Niigata
2016.11.21	新潟大学　学長賞 (若手教員研究奨励) Niigata
2005.3.25	早稲田大学　博士（理学）受領者代表

2024 - 2026	科研費　基盤研究(B) 24K00519 923万円 KAKEN
2023	新潟大学　学術出版奨励賞 10万円 Niigata
2021	新潟大学　優秀論文表彰 10万円 Niigata
2019 - 2022	科研費　基盤研究(C) 19K03418 429万円 KAKEN
2018	新潟大学　国際学会等参加支援事業 20万円
2017	新潟大学　科学研究費助成事業応募支援プログラム 70万円
2016	新潟大学　学長賞 (若手教員研究奨励) 80万円 Niigata
2013 - 2016	科研費　基盤研究(C) 25400027 481万円 KAKEN
2010 - 2012	科研費　若手研究(B) 22740028 234万円 KAKEN
2009	立教大学　学術推進特別重点資金 (立教SFR) 50万円 Rikkyo
2008	立教大学　学術推進特別重点資金 (立教SFR) 50万円 Rikkyo
2007	早稲田大学　特定課題研究 (2007B-067) 45万円
2006	早稲田大学　特定課題研究 (2006A-850) 20万円
2004 - 2005	科研費　特別研究員奨励費 04J01682 190万円 KAKEN

2024 - 2027	科研費　基盤研究(C) 24K06647 KAKEN
2020 - 2024	科研費　基盤研究(A) 20H00115 KAKEN
2010 - 2014	科研費　基盤研究(C) 22540032 KAKEN
2007 - 2008	科研費　基盤研究(C) 19540057 KAKEN
2006 - 2009	科研費　基盤研究(C) 18540048 KAKEN

Research Interests

Preprints arXiv / Front for the arXiv

Papers MathSciNet / zbMATH

Ph.D. Dissertation

Refereed Articles & Surveys

Books

Honors

Research Grants

Research Grants (Co-Investigator)

Visits & Attendances