Publications

Preprints

  • Hiroshi Tamaru; "離散的な対称空間と quandle", In: Sugaku (数学), to appear.

Published Papers

2024

  1. Hiroshi Tamaru; "Quandles from the viewpoint of symmetric spaces --- some open problems", In: 部分多様体幾何とリー群作用 2023 記録集 (2024), 159--167. [ (April 2024) | Google scholar]
  2. Konomi Furuki, Hiroshi Tamaru; "Homogeneous quandles with abelian inner automorphism groups and vertex-transitive graphs", Internat. Elect. J. Geom. 17 (2024), 184--198. [ 10.36890/iejg.1438745 (April 2024) | Google scholar ]
  3. Ryoya Kai, Hiroshi Tamaru; "A note on quandle Euler characteristics", In: Quandles and Symmetric Spaces 2023, OCAMI Reports (2024), (1): 1--11. [ 10.24544/omu.20240328-001 (April 2024) | Google scholar ]

2023

  1. Hiroshi Tamaru; "On the moduli spaces of left-invariant Riemannian metrics on Lie groups --- a report on the one-dimensional case", Proceedings of The 24th International Workshop on Differential Geometry & Related Fields (2023), 249--257.
  2. Hiroshi Tamaru; "左不変リーマン計量のモジュライ空間が1 次元となるLie 群について", In: 部分多様体幾何とリー群作用 2022 記録集 (2023), 137--149.
  3. Luis Pedro Castellanos Moscoso, Hiroshi Tamaru; "A classification of left-invariant symplectic structures on some Lie groups", Beitrage Algebra Geom. 64 (2023), 471--491. [ 10.1007/s13366-022-00643-1 (May 2022) | Google scholar ]
  4. Yuji Kondo, Hiroshi Tamaru; "A classification of left-invariant Lorentzian metrics on some nilpotent Lie groups", Tohoku Math. J. (2) 75 (2023), 89--117. [ 10.2748/tmj.20211122 (March 2023) | Google scholar ]

2022

  1. Takahiro Hashinaga, Akira Kubo, Yuichiro Taketomi, Hiroshi Tamaru; "A Lie theoretic interpretation of realizations of some contact metric manifolds", In: New Horizons in Differential Geometry and Its Related Fields (2022), 71--90. [ 10.1142/9789811248108_0005 (May 2022) | Google scholar ]
  2. Akira Kubo, Mika Nagashiki, Takayuki Okuda, Hiroshi Tamaru; "A commutativity condition for subsets in quandles --- a generalization of antipodal subsets", In: Differential Geometry and Global Analysis: In Honor of Tadashi Nagano. Contemp. Math. 777 (2022), 103--125. [ 10.1090/conm/777/15631 (May 2022) | Google scholar ]
  3. Hiroshi Tamaru; "対称空間論の離散化とカンドル代数, Part V", In: Deepening and merging geometric structures related to submanifold theory, RIMS Kokyuroku 2210 (2022), 57--65.
  4. Hiroshi Tamaru; "Quandles from the viewpoint of symmetric spaces --- a survey", In: Quandles and Symmetric Spaces 2021, OCAMI Reports 9 (2022), 100--113. [ 10.24544/ocu.20220209-001 | Google scholar ]

2021

  1. Akira Kubo, Takayuki Okuda, Hiroshi Tamaru; "Remarks on totally geodesic complex curves in Hermitian symmetric spaces", In: Proceedings of The 23rd International Differential Geometry Workshop on Submanifolds in Homogeneous Spaces & Related Topics (2021), 129--139.
  2. Miguel Dominguez-Vazquez, Victor Sanmartin-Lopez, Hiroshi Tamaru; "Codimension one Ricci soliton subgroups of solvable Iwasawa groups", J. Math. Pures Appl. 152 (2021), 69--93. [ 10.1016/j.matpur.2021.05.008 (open access) | Google scholar ]
  3. Hiroshi Tamaru; "可解岩澤群内の余次元 1 リッチソリトン部分群", In: 研究集会「部分多様体幾何とリー群作用 2020」記録集 (2021), 21--34.

2020

  1. Hiroshi Tamaru; 書評 "Marcos M. Alexandrino, Renato G. Bettiol: Lie Groups and Geometric Aspects of Isometric Actions", In: Sugaku (数学) 72 (2020), 218--220.

2019

  1. Takayuki Okuda, Akira Kubo, Hiroshi Tamaru; "Dynkin indices for totally geodesic submanifolds in compact symmetric spaces", In: Proceedings of the 22nd International Workshop on Differential Geometry of Submanifolds in Symmetric Spaces and Related Problems (2019), 195--200.
  2. Shinobu Fujii, Hiroshi Tamaru; "Moment maps and isoparametric hypersurfaces in spheres --- some recent results", In: Proceedings of the 22nd International Workshop on Differential Geometry of Submanifolds in Symmetric Spaces and Related Problems (2019), 97--104. [ Google scholar ]
  3. Hiroshi Tamaru; "対称空間論の離散化とカンドル代数, Part IV", In: 研究集会「部分多様体論・湯沢 2018」記録集 (2019).

2018

  1. Hiroshi Tamaru; "対称空間論の離散化とカンドル代数, Part III", In: 第35回代数的組合せ論シンポジウム記録集 (2018), 67--73.
  2. Sadahiro Maeda, Hiroshi Tamaru, Hiromasa Tanabe; "Curvature properties of homogeneous real hypersurfaces in nonflat complex space forms", Kodai Math. J. 41 (2018), 315--331. [ 10.2996/kmj/1530496844 | Google scholar ]
  3. Yuichiro Taketomi, Hiroshi Tamaru; "On the nonexistence of left-invariant Ricci solitons --- a conjecture and examples", Transf. Groups 23 (2018), 257--270. [ 10.1007/s00031-017-9439-4 | Google scholar ]
  4. Jong Taek Cho, Takahiro Hashinaga, Akira Kubo, Yuichiro Taketomi, Hiroshi Tamaru; "Realizations of some contact metric manifolds as Ricci soliton real hypersurfaces", J. Geom. Phys. 123 (2018), 221--234. [ 10.1016/j.geomphys.2017.08.013 | arXiv:1702.07256 | Google scholar ]

2017

  1. Jong Taek Cho, Takahiro Hashinaga, Akira Kubo, Yuichiro Taketomi, Hiroshi Tamaru; "The solvable models of noncompact real two-plane Grassmannians and some applications", In: Hermitian-Grassmannian Submanifolds, Springer Proc. Math. Stat. 203 (2017), 311--321. [ 10.1007/978-981-10-5556-0_26 | Google scholar ]
  2. Takahiro Hashinaga, Hiroshi Tamaru; "Three-dimensional solvsolitons and the minimality of the corresponding submanifolds", Internat. J. Math. 28 (2017), 1750048 [31 pages]. [ 10.1142/S0129167X17500483 | Google scholar ]

2016

  1. Akira Kubo, Kensuke Onda, Yuichiro Taketomi, Hiroshi Tamaru; "On the moduli spaces of left-invariant pseudo-Riemannian metrics on Lie groups", Hiroshima Math. J. 46 (2016), 357--374. [ 10.32917/hmj/1487991627 | Google scholar ]
  2. Takahiro Hashinaga, Akira Kubo, Hiroshi Tamaru; "Homogeneous Ricci soliton hypersurfaces in the complex hyperbolic spaces", Tohoku Math. J. (2) 68 (2016), 559--568. [ 10.2748/tmj/1486177215 | Google scholar | MR3605447 ]
  3. Yoshitaka Ishihara, Hiroshi Tamaru; "Flat connected finite quandles", Proc. Amer. Math. Soc. 144 (2016), 4959--4971. [ 10.1090/proc/13095 | Google scholar | MR3544543 ]
  4. Hiroshi Tamaru; "The space of left-invariant Riemannian metrics", In: Geometry and Topology of Manifolds, Springer Proc. Math. Stat. 154 (2016), 315--326. [ 10.1007/978-4-431-56021-0_17 | Google scholar | MR3555990 ]
  5. Seiichi Kamada, Hiroshi Tamaru, Koshiro Wada; "On classification of quandles of cyclic type", Tokyo J. Math. 39 (2016), 157--171. [ 10.3836/tjm/1459367262 | Google scholar | MR3543136 ]
  6. Takahiro Hashinaga, Hiroshi Tamaru, Kazuhiro Terada; "Milnor-type theorems for left-invariant Riemannian metrics on Lie groups", J. Math. Soc. Japan 68 (2016), 669--684. [ 10.2969/jmsj/06820669 | Google scholar | MR3488140 ]

2015

  1. Sadahiro Maeda, Hiroshi Tamaru; "Naturally reductive homogeneous real hypersurfaces in a nonflat complex space form", In: Topology Appl. 196, Part B (2015), 675--683. [ 10.1016/j.topol.2014.01.020 | Google scholar | Zbl 1329.53075 | MR3431006 ]
  2. Hiroshi Tamaru; "対称空間論の離散化とカンドル代数, Part II". In: 研究集会「部分多様体論・湯沢 2014」記録集, 55--60 (2015). [ Link ]
  3. Shinobu Fujii, Hiroshi Tamaru; "Moment maps and isoparametric hypersurfaces in spheres --- Hermitian cases", Transf. Groups 20 (2015), 417--436. [ 10.1007/s00031-015-9305-1 | Google scholar | Zbl 1330.53111 | MR3348562 ]
  4. Hiroshi Tamaru; "対称空間論の離散化とカンドル代数, Part I", In: Geometry and Analysis (福岡大学微分幾何研究会 2014 記録集), 99--107 (2015). [ pdf (218KB) ]

2014

  1. Hiroshi Tamaru; "Group actions on symmetric spaces related to left-invariant geometric structures", In: Development of group actions and submanifold theory, RIMS Kokyuroku 1929 (2014), 1--12. [ Google scholar ]
  2. Takuya Fujimaru, Akira Kubo, Hiroshi Tamaru; "On totally geodesic surfaces in symmetric spaces of type AI", In: Real and Complex Submanifolds, Springer Proc. Math. Stat. 106 (2014), 211--227. [ 10.1007/978-4-431-55215-4_19 | Google scholar | Zbl 1321.53060 | MR3333381 ]
  3. Carlos Olmos, Silvio Reggiani, Hiroshi Tamaru; "The index of symmetry of compact naturally reductive spaces", Math. Z. 277 (2014), Issue 3--4, 611--628. [ 10.1007/s00209-013-1268-0 | Google scholar | Zbl 1302.53056 | MR3229956 ]

2013

  1. Akira Kubo, Hiroshi Tamaru; "A sufficient condition for congruency of orbits of Lie groups and some applications", Geom. Dedicata 167 (2013), no. 1, 233--238. [ 10.1007/s10711-012-9811-4 | Google scholar | MR3128778 | Zbl 1284.57031 ]
  2. Jurgen Berndt, Hiroshi Tamaru; "Cohomogeneity one actions on symmetric spaces of noncompact type", J. Reine Angew. Math. 683 (2013), 129--159. [ 10.1515/crelle-2012-0002 | Google scholar | Zbl 1280.53049 | MR3181551 ]
  3. Hiroshi Tamaru; "Two-point homogeneous quandles with prime cardinality", J. Math. Soc. Japan 65 (2013), no. 4, 1117--1134. [ 10.2969/jmsj/06541117 | Google scholar | MR3127819 | Zbl 1295.57011 ]
  4. Hiroshi Tamaru; "The space of left-invariant metrics --- on a generalization of Milnor frames", In: Proceedings of The Seventeenth International Workshop on Diff. Geom. 17 (2013), 55--65. [ Google scholar | Zbl 1295.53047 | MR3203382 ]
  5. Takahiro Hashinaga, Akira Kubo, Hiroshi Tamaru; "Some topics of homogeneous submanifolds in complex hyperbolic spaces", In: Differential Geometry of Submanifolds and its Related Topics, 230--244, World Scientific, 2013. [ 10.1142/9789814566285_0020 | Google scholar | Zbl 1300.53056 | MR3203486 ]

2012 and before

  1. Tatsuyoshi Hamada, Yuji Hoshikawa, Hiroshi Tamaru; "Curvatures properties of Lie hypersurfaces in the complex hyperbolic space", J. Geom. 103 (2012), no. 2, 247--261. [ 10.1007/s00022-012-0127-1 | Google scholar | MR2995128 | Zbl 1266.53057 ]
  1. Hiroshi Tamaru; "Parabolic subgroups of semisimple Lie groups and Einstein solvmanifolds", Math. Ann. 351 (2011), no. 1, 51--66. [ DOI | Google scholar | MR2824845 | Zbl 1227.53062 ]
  2. Hiroshi Kodama, Atsushi Takahara, Hiroshi Tamaru; "The space of left-invariant metrics on a Lie group up to isometry and scaling", Manuscripta Math. 135 (2011), no. 1--2, 229--243. [ DOI | Google scholar | MR2783396 | Zbl 1230.53048 ]
  3. Hiroshi Tamaru; "Parabolic subgroups and submanifold geometry of noncompact symmetric spaces", In: Proceedings of The Fifteenth International Workshop on Diff. Geom. 15 (2011), 29--38. [ Google scholar | Zbl 1237.53041 | MR2894276 ]
  4. Shinobu Fujii, Hiroshi Tamaru; "Moment maps and isoparametric hypersurfaces in spheres --- an introduction", In: Proceedings of The Fifteenth International Workshop on Diff. Geom. 15 (2011), 19--27. [ Google scholar | Zbl 1251.53033 | MR2894275 ]
  5. Jurgen Berndt, Jose Carlos Diaz-Ramos, Hiroshi Tamaru; "Hyperpolar homogeneous foliations on symmetric spaces of noncompact type", J. Differential Geom. 86 (2010), no. 2, 191--235. [ Project Euclid | Google scholar | MR2772550 | Zbl 1218.53030 ]
  6. Hiroshi Tamaru; "Homogeneous submanifolds in noncompact symmetric spaces", In: Proceedings of The Fourteenth International Workshop on Diff. Geom. 14 (2010), 111--144. [ Google scholar | Zbl 1218.53059 | MR2757813 ]
  7. Hiroshi Tamaru; "非コンパクト対称空間への良い作用の構成法", In: 部分多様体幾何とリー群作用 2010 記録集, 39--48 (2010). [ Google scholar ]
  8. Hiroshi Tamaru, Hisashi Yoshida; "Lie groups locally isomorphic to generalized Heisenberg groups", Proc. Amer. Math. Soc. 136 (2008), no. 9, 3247--3254. [ DOI | Google scholar | MR2407090 | Zbl 1155.53028 ]
  9. Hiroshi Tamaru; "Noncompact homogeneous Einstein manifolds attached to graded Lie algebras", Math. Z. 259 (2008), no. 1, 171--186. [ DOI | Google scholar | MR2377747 | Zbl 1151.53044 ]
  10. Hiroshi Tamaru; "複素双曲空間内の等質超曲面の分類", In: 部分多様体論・湯沢2007 報告集, 5--15 (2008). [ Google scholar ]
  11. Jurgen Berndt, Hiroshi Tamaru; "Cohomogeneity one actions on noncompact symmetric spaces of rank one", Trans. Amer. Math. Soc. 359 (2007), no. 7, 3425--3438. [ DOI | Google scholar | MR2299462 | Zbl 1117.53041 ]
  12. Hiroshi Tamaru; "Parabolic subgroups and Einstein solvmanifolds" (in Japanese), In: 大阪大学微分幾何研究集会 (坂根先生還暦記念), 75--85 (2006). [ pdf (155KB) | Google scholar ]
  13. Hiroshi Tamaru; "A class of noncompact homogeneous Einstein manifolds", In: Differential Geometry and its Applications, 119--127, Matfyzpress, Prague, 2005. [ Google scholar | Zbl 1112.53035 | MR2268926 ]
  14. Jurgen Berndt, Hiroshi Tamaru; "Cohomogeneity one actions on noncompact symmetric spaces with a totally geodesic singular orbit", Tohoku Math. J. 56 (2004), no. 2, 163--177. [ DOI | Google scholar | Zbl 1066.53097 | MR2053317 ]
  15. Hiroshi Tamaru; "Cohomogeneity one actions on noncompact symmetric spaces of rank one" (in Japanese, with English abstract), In: 部分多様体論・湯沢2003 報告集, 43--48 (2004).
  16. Hiroshi Tamaru; "Cohomogeneity one actions on symmetric spaces", In: Theory of Lie groups and manifolds. Sophia Kokyuroku in Mathematics 45 (2003), 105--120. [ pdf (205KB) | Zbl 1038.53052 ]
  17. Jurgen Berndt, Hiroshi Tamaru; "Homogeneous codimension one foliations on noncompact symmetric spaces", J. Differential Geom. 63 (2003), no. 1, 1--40. [ Project Euclid | Google scholar | Zbl 1070.53011 | MR2015258 ]
  18. Hiroshi Tamaru; "Two-step nilpotent Lie groups and homogeneous fiber bundles", Ann. Global Anal. Geom. 24 (2003), no. 1, 53--66. [ DOI | Google scholar | Zbl 1038.53049 | MR1990085 ]
  19. Hiroshi Tamaru; "Cohomogeneity one actions on symmetric spaces with a totally geodesic singular orbit" (in Japanese), RIMS Kokyuroku 1292 (2002), 106--114. [ Google scholar | MR1981790 ]
  20. Hiroshi Tamaru; "Two-step nilpotent Lie groups" (in Japanese, with English abstract), In: 部分多様体論・湯沢1999 報告集, 3--8 (2000). [ Google scholar ]
  21. Hiroshi Tamaru; "On certain subalgebras of graded Lie algebras", Yokohama Math. J. 46 (1999), no. 2, 127--138. [ Google scholar | Zbl 1121.17302 | MR1697854 ]
  22. Hiroshi Tamaru; "Riemannian g.o. spaces fibered over irreducible symmetric spaces", Osaka J. Math. 36 (1999), no. 4, 835--851. [ Project Euclid | Google scholar | Zbl 0963.53026 | MR1745654 ]
  23. Hiroshi Tamaru; "The local orbit types of symmetric spaces under the actions of the isotropy subgroups", Differential Geom. Appl. 11 (1999), no. 1, 29--38. [ DOI | Google scholar | Zbl 0941.53035 | MR1702475 ]
  24. Hiroshi Tamaru; "Weakly symmetric spaces and Riemannian g.o. spaces" (in Japanese), RIMS Kokyuroku 1069 (1998), 43--52. [ Google scholar | Zbl 0952.53026 | MR1701999 ]
  25. Hiroshi Tamaru; "Riemannian geodesic orbit metrics on fiber bundles", Algebras, Groups Geom. 15 (1998), no. 1, 55--67. [ Google scholar | Zbl 1055.53503 | MR1674790 ]