Research

Papers/Preprints

1. On Hodge structures of compact complex manifolds with semistable degenerations, preprint. 

2. Construction of non-Kähler Calabi-Yau manifolds by log deformations, to appear in Proceedings of Nottingham Algebraic Geometry Seminar. 

3. (wiith Yuchen Liu and Luca Tasin), Infinitely many families of Sasaki-Einstein metrics on spheres, to appear in JDG. 

4. (with Luca Tasin), On K-stability of Fano weighted hypersurfaces, appeared in AG. 

5. Examples of non-Kähler Calabi-Yau manifolds with arbitrarily large b_2, appeared in JTop. 

6. On birational boundedness of some Calabi-Yau hypersurfaces, appeared in the proceedings of  the Moscow-Shanghai-Pohang conference. 

7. (with Kenji Hashimoto), Examples of non-Kähler Calabi-Yau 3-folds with arbitrarily large b_2, appeared in G&T.

8. (with Marco Pizzato and Luca Tasin), Effective non-vanishing for Fano weighted complete intersections, appeared in ANT. 

9. (with Stephen Coughlan), Smoothing cones over K3 surfaces, appeared in EPIGA. 

10. Deformations of weak Q-Fano threefolds, appeared in IJM. 

11. (with Shinnosuke Okawa), On the noncommutative rigidity of the moduli stack of stable pointed curves, preprint. 

12. Deforming elephants of Q-Fano threefolds, appeared in JLMS. 

13. On deformations of Q-Fano threefolds II, appeared in Crelle. 

14. Unobstructedness of deformations of weak Fano manifolds, appeared in IMRN. 

15. On deformations of Q-Fano threefolds, appeared in JAG. 

16. Seshadri constants on rational surfaces with anticanonical pencils, appeared in JPAA.

Schedule (plan): Visit University of Milan (March--April,  September 2024--February 2025).    

Talks 

1. On birational boundedness of Calabi-Yau hypersurfaces, Osaka Mirror Symmetry Seminar, 13th Dec. 2023, Osaka university. 

2. Infinitely many families of Sasaki-Einstein metrics on spheres, Niigata Algebra symposium, 6th Dec. 2023, Niigata university. 

3. Birational boundedness of some Calabi-Yau hypersurfaces, Algebraic Geometry Seminar, 6th Oct. 2023, University of Milan. 

4. Deformations of Fano and Calabi-Yau varieties (mini-course (3 talks)), Algebraic Geometry Workshop in Bologna, 26th-28th Sep. 2023, University of Bologna. 

5. Construction of non-Kähler Calabi-Yau manifolds by log deformations, Geometry seminar, 15th May. 2023, Osaka university. 

6. On birational boudedness of some Calabi-Yau hypersurfaces, The 1st Algebraic Geometry Atami Symposium, 8th Feb. 2023, The building of the Izu Mainichi Shimbun (Izu My Room).   

7. Construction of non-Kähler Calabi-Yau manifolds by log deformations, Workshop on Complex geometry in Osaka 2022, 22nd Sep. 2022, Osaka university. 

8. Sasaki--Einstein metrics on spheres, Geometry Symposium, 30th Aug. 2022, Tokyo university of science. 

9. Infinitely many families of Sasaki-Einstein metrics on spheres, Geometry Colloquium, 22nd Jul. 2022, Hokkaido university. 

10. Infinitely many families of Sasaki-Einstein metrics on spheres, Tsukuba Differential Geometry Seminar, 10th May. 2022, online(Zoom). 

11. Construction of non-Kähler Calabi-Yau manifolds by log deformations, Japanese-European Symposium on Symplectic Varieties and Moduli Spaces– Sixth Edition, 17th Mar. 2022, Waseda university. 

12. On K-stability of Fano weighted hypersurfaces, IBS-CGP Algebraic Geometry Seminar, 8th Mar. 2022, online (Zoom). 

13. On K-stability of Fano weighted hypersurfaces, Explicit Birational Geometry seminar, 29th Dec. 2021, online (Zoom). 

14. Construction of non-Kähler Calabi-Yau manifolds by log deformations, Tokyo-Kyoto Algebraic Geometry seminar, 14th Dec. 2021, online (Zoom). 

15. On K-stability of Fano weighted hypersurfaces, Osaka Algebraic Geometry seminar, 13th Dec. 2021, online (Zoom). 

16. Construction of non-Kähler Calabi-Yau manifolds by log deformations, Emmy Noether Kolloquium, 19th May. 2021, online (Zoom). 

17. Construction of non-Kähler Calabi-Yau manifolds by log deformations, Online Algebraic Geometry seminar, 18th Mar. 2021, online (Teams). 

18. Birational boundedness of some Calabi-Yau hypersurfaces, Zoom Algebraic Geometry seminar, 16rd Mar. 2021, online (Zoom). 

19. Birational boundedness of some Calabi-Yau hypersurfaces, Tokyo-Kyoto Algebraic Geometry seminar, 13rd Jan. 2021, online (Zoom). 

20. On log deformations of normal crossing Calabi-Yau varieties, Aspects of Mirror Symmetry, 16th Sep, 2020, online (Zoom). 

21. Construction of non-Kähler Calabi-Yau 3-folds by log deformations, Geometry Seminar (Osaka university), 6th July, 2020, online (Zoom). 

22. Deformations of Fano and Calabi-Yau varieties (5 talks), COMPLEX ALGEBRAIC GEOMETRY WINTER SCHOOL, 27th Jan-1st Feb, 2020, Nesin Mathematics Village. 

23. Construction of Calabi-Yau manifolds by log deformations, Niigata Algebra seminar, 10. Jan. 2020, Niigata university. 

24. On log deformations of degenerate Calabi-Yau varieties, Yufuin Algebraic Geometry Workshop, 27. Dec. 2019, Nihon Bunri university. 

25. On log deformations of degenerate Calabi-Yau varieties, Birational Geometry, Kähler-Einstein metrics and Degenerations, 18. Nov, IBS center for Geometry and Physics. 

26. On log deformations of degenerate Calabi-Yau varieties, Algebraic geometry seminar, 5. Nov. 2019, University of Milan. 

27. Deformations of Fano and Calabi-Yau varieties (3 talks), Groups, Arithmetic & Algebraic Geometry Seminar, 30,31.Oct.& 1.Nov., EPFL. 

28. On log deformations of degenerate Calabi-Yau varieties, Mini Workshop on Geometry of Moduli Spaces , 10. Oct. 2019, Kobe university. 

29. Construction of non-Kähler Calabi-Yau 3-folds by log deformations, Younger generations in Algebraic and Complex geometry, 6. Aug. 2019, Okayama University.

30. Construction of non-Kähler Calabi-Yau 3-folds by smoothing normal crossing varieties, Algebraic Geometry seminar, 9.Jul. 2019, The university of Tokyo.

31. Construction of non-Kähler Calabi-Yau 3-folds by log deformations, Birational Geometry, Kähler-Einstein metrics and Degenerations,10.Jun. 2019, Shanghai Tech. University.

32. Construction of non-Kähler Calabi-Yau 3-folds by smoothing normal crossing varieties, Algebraic Geometry International Conference, 7.Jun. 2019, KIAS.

33. On quasi-smooth weighted complete intersections, The 17th Affine Algebraic Geometry Meeting, Mar. 2019, Kanswei Gakuin University (Umeda).  

34. Construction of non-Kähler Calabi-Yau 3-folds by smoothing normal crossing varieties, Algebraic geometry seminar, Jan. 2019, Kyoto university.

35. Construction of non-Kähler Calabi-Yau 3-folds by smoothing normal crossing varieties, Geometry&Mathematical Physics seminar, Nov. 2018, Loughborough university.

36. Construction of non-Kähler Calabi-Yau 3-folds by log deformations, Algebraic Geometry seminar, Nov. 2018, University of Warwick. 

37. Construction of non-Kähler Calabi-Yau 3-folds by smoothing normal crossing varieties, Birational geometry and related topics, Nov. 2018, Fudan university (SCMS). 

38. Construction of Calabi-Yau manifolds by log deformation theory, Algebra seminar, Oct. 2018, Kobe university.

39. Effective non-vanishing for weighted complete intersections, Geometry of Projective varieties and related topics 2018, Oct. 2018, Kochi university of technology.

40. On deformations of log Calabi-Yau varieties, 代数学シンポジウム(Algebra Symposium), Sep. 2018, Tokyo Institute of Technology. 

41. On log deformations of Calabi-Yau varieties, ホッジ理論と代数幾何学 (Hodge theory and algebraic geometry), Aug. 2018, Tokyo Denki University. 

42. On deformations of log Calabi-Yau varieties, Danwa-kai, Jun. 2018, Saitama university. 

43. Log deformations of VNC Calabi-Yau varieties, Positivity in algebraic geometry, Jun. 2018, Yonsei university. 

44. Log deformations of VNC Calabi-Yau varieties, Algebra seminar, May. 2018, Tohoku university. 

45. Effective non-vanishing for weighted complete intersections, Higher dimensional algebraic geometry, Mar. 2018, The university of Tokyo. 

46. Effective non-vanishing for weighted complete intersections, Algebra Seminar (joint with Hiroshima Complex Analysis seminar), Nov. 2017,Hiroshima university. 

47. Effective non-vanishing for weighted complete intersections, Algebra Seminar, Oct. 2017, Kobe university. 

48. Effective non-vanishing for weighted complete intersections, the 4-th Seoul Seminar on Algebraic Geometry, May. 2017, Start up Campus (Pangyo, Korea). 

49. Deformations of Calabi-Yau/Fano varieties (3 talks), Current Topics in Algebraic and Symplectic Geometry, Mar. 2017, Kyoto University. 

50. Deformations of cones over K3 surfaces, THE 15TH AFFINE ALGEBRAIC GEOMETRY MEETING, Mar. 2017, Kwansei Gakuin University (Umeda). 

51. Log deformations of VNC Calabi-Yau varieties, The 2nd Higher dimensional algebraic geometry Echigo Yuzawa symposium, Feb. 2017, Yuzawa-cho Kouminkan.  

52. Log deformations of VNC Calabi-Yau varieties, the 4th workshop on Algebraic Geometry -Ube-, Jan. 2017, National Institute of Technology (Ube College). 

53. Log deformations of Calabi-Yau varieties, Algebra seminar, Oct. 2016, Kobe university.

54. Deformations of cones over K3 surfaces, TSUDA COLLEGE AND OIST JOINT WORKSHOP ON CALABI–YAU VARIETIES:ARITHMETIC, GEOMETRY AND PHYSICS, Aug. 2016, The university of Tokyo. 

55. Deformations of cones over K3 surfaces, Waseda Algebraic geometry seminar, May. 2016, Waseda university. 

56. Bound of singularities on Q-Fano 3-folds, Workshop on Hyperplane Arrangements and Singularity Theory, Mar. 2016, Hokkaido university. 

57. Deformations of cones over K3 surfaces, Algebraic geometry seminar, Mar. 2016, Rome Tre university. 

58. Deformations of cones over K3 surfaces, 11th Daisuu-Kaiseki-Kikagaku seminar, Feb. 2016, Kagoshima university.  

59. Bound of singularities on Q-Fano 3-folds, ''Higher dimensional algebraic geometry and around, Kobe-Kyoto'', Feb. 2016, Kobe university. 

60. Deformations of Q-Fano 3-folds, Workshop on deformation and moduli, Jan. 2016, Riviera Hotel (Busan). 

61. A bound of singularities on a Q-Fano 3-fold, Singularities and invariants on higher dimensional algebraic varieties, Dec. 2015, RIMS.

62. A bound of singularities on a Q-Fano 3-fold, KIAS algebraic geometry meeting, Dec. 2015, KIAS. 

63. Deformations of Fano varieties, Algebraic geometry seminar, Dec. 2015, KIAS.

64. Deformations of cones over K3 surfaces, Algebra Seminar, Nov. 2015, Kobe university. 

65. Deformations of Fano varieties, Colloquium, Nov. 2015, Kobe university. 

66. Introduction to the paper by Cantat-Lamy, Tambara Algebraic Geometry Seminar, Sep. 2015, Tambara Institute of Mathematical Sciences. 

67. Deformations of cones over K3 surfaces, Sep. 2015, Oberseminaire, Leibniz Universität Hannover.

68. Deformations of cones over K3 surfaces, Aug. 2015, Higher Dimensional Algebraic Geometry, National Taiwan University.

69. Deformations of weak Fano varieties, May. 2015, Algebraic Geometry Seminar, the University of Tokyo. 

70. Unobstructed deformations of Fano varieties, Apr. 2015, Algebraic Geometry Seminar, Kyoto university. 

71. Deforming elephants of Q-Fano 3-folds, Oct. 2014, Kinosaki Symposium on algebraic geometry 2014, Kinosaki International Arts center. 

72. Deformations of Fano varieties, Sep. 2014, Oberseminar, Max Planck Institute for Mathematics. 

73. Deforming elephants of Q-Fano 3-folds, Feb. 2014, Birational geometry and foliations, Hausdorff Reserch Institute for Mathematics.  

74. Deforming elephants of Q-Fano 3-folds, Jan. 2014, Algebraic geometry seminar, The university of Tokyo. 

75. Deformations of Fano 3-folds with terminal singularities, Oct. 2013, Algebraic geometry seminar, Princeton university. 

76. Deformations of weak Fano manifolds, Sep. 2013, Calf seminar, University of Warwick. 

77. Deformations of weak Fano manifolds, Jun. 2013, Algebraic geometry and complex geometry seminar, Osaka university.  

78. Deformations of Fano 3-folds with terminal singularities, Jan. 2013, MAGIC seminar, Imperial College London.

79. Deformations of Fano 3-folds with terminal singularities, Jan. 2013, Workshop on birational geometry, The university of Tokyo.

80. Deformations of Q-Fano 3-folds and their general elephants, Jun. 2012,NCTS/TPE Seminar in Algebraic Geometry, National TaiwanUniversity.  

81. Deformations of Fano 3-folds with terminal singularities, Jun. 2012, Algebraic geometry seminar, Ajou university.

82. Deformations of Fano 3-folds with terminal singularities, May. 2012, WCU workshop on classification and construction of algebraic varieties, Busan (Seacloud Hotel).

83. Deformations of Fano 3-folds with terminal singularities, Apr. 2012, Homological Methods in Algebraic Geometry, Steklov Mathematical Institute. 

84. Deformations of singular Fano 3-folds, April. 2012, YRM 2012, University of Bristol

85. Deformation theoretic approach to the classification of singular Fano 3-folds, Mar. 2012, Calf seminar, University of Warwick

86. Deformations of Fano 3-folds with terminal singularities, Feb. 2012, Korova@Warwick Day, University of Warwick

87. Deformations of Fano 3-folds with terminal singularities, Feb.,2012, Algebraic Geometry Seminar, University of Warwick

88. Seshadri constants on rational surfaces with anticanonical pencils, Dec., 2009, Algebraic Geometry Seminar, Nagoya university.

89. Seshadri constants on rational surfaces with anticanonical pencils, Nov., 2009, Geometry of Projective Varieties and Related Topics, 2009, Kochi university.

90. Seshadri constants on rational surfaces with anticanonical pencils, Oct., 2009, Algebraic Geometry Seminar, Kyushu university.

91. Introduction to the papers by Gross-Siebert, Jul, 2009, Tambara Algebraic Geometry Summer School, Tambara Institute of Mathematical Sciences. 

92. Seshadri constants on rational surfaces with anticanonical pencils, Jul., 2009, Algebraic Geometry Seminar, The university of Tokyo.

93. Seshadri constants on rational surfaces with anticanonical pencils, May., 2009, Singularity Seminar, Nihon university. 

94. Seshadri constants on rational surfaces with anticanonical pencils, Feb., 2009, The 6th Kinosaki Newcomer Seminar, Kinosaki Conference hall

Poster session 

• Deforming elephants of Q-Fano 3-folds, BrAG, Sep. 2014, University of Warwick. 

• Deformations of Q-Fano 3-folds, AGNES, Oct. 2013, Boston college. 

• Deformations of Q-Fano 3-folds, Foliation theory in algebraic geometry, Sep. 2013, Simons foundation. 

• Deformation of weak Fano manifolds, Apr. 2013, Characteristic p methods in London, Imperial College. 

• Deformations of Q-Fano 3-folds, Sep. 2012, Algebraic and Complex geometry, Leibniz Universität Hannover. 

• Seshadri constants on rational surfaces with anticanonical pencils, Oct., 2009, Kinosaki Algebraic Geometry Symposium, Kinosaki conference hall.

Informal talks

• • Introduction to deformations of projective varieties, Jul. 2013, Junior Algebraic Geometer meeting, University of Warwick.

• Deformation-obstruction theory for algebraic varieties, Feb. 2012, Postgraduate seminar, University of Warwick

• The Fujita approximation and Okounkov bodies (Survey on a part of arXiv:0805.4559), Nov., 2011, Okounkov body seminar, University of Warwick 

• Smoothing of singular algebraic varieties by flat deformation, May., 2011, Postgraduate Seminar, University of Warwick.