Séverin Philip

Postdoctoral Researcher JSPS

Arithmetic Geometry and Number Theory

Research Institute for Mathematical Sciences
Kyoto University
Kitashirakawa-Oiwakecho, Sakyo-ku

Kyoto 606-8502, Japan

Maskawa building, office : 202



Research interests

My work deals mainly with the geometry of abelian varieties and their arithmetic reduction properties in particular regarding semi-stability. My interests include weak approximation for rational points and inverse Galois problems (e.g. Grunwald problems). I started more recently to develop a project on the moduli stacks of curves and on the stable reduction and arithmetic properties of their special loci.

Articles and thesis
  • 5 - Groupes de monodromie finie des variétés abéliennes. 2024 (34p). [pdf]  

  • 4 - On Oda's problem and special loci. 2023 (37p). Joint work with B. Collas. [pdf, arxiv]  

  • 3 - On the semi-stability degree for abelian varieties. Bulletin of the London Mathematical Society. 2022. (available online at Bulletin of the London Mathematical Society) [pdf, arxiv]  

  • 2 - Variétés abéliennes CM et grosse monodromie finie sauvage. Journal of Number Theory. 240. 2022. p. 163-195 [pdf, arxiv]  

  • 1 - Fields of definition of abelian subvarieties. Journal de Théorie des Nombres de Bordeaux. 2022. (available online at Journal de Théorie des Nombres de Bordeaux) [pdf, arxiv]  

  • 0 - Thèse de doctorat  : Réduction semi-stable des variétés abéliennes, Université Grenoble Alpes, Institut Fourier. 2021 [pdf]
Curriculum vitae
Invited Talks at seminars and conferences
  • 2024 Apr. Niigata Algebra seminar , Niigata universty, Oda's problem for cyclic special loci.
  • 2024 Mar. Anabelian Geometry in Tokyo , Tokyo Institute of Technology, Oda's problem for cyclic special loci.
  • 2024 Mar. The 20th Mathematics Conference for Young Researchers , Hokkaido University (online), The classical problem of Oda and an analogue for cyclic special loc.
  • 2024 Mar. Low dimensional topology and number theory XV , Kyushu University, The maximal degeneration method for special loci.
  • 2024 Jan. Aichi Number Theory seminar , Nagoya University, On Oda's problem and special loci.
  • 2023 Dec. Copenhagen Number Theory seminar , University of Copenhagen (online), A new construction for finite monodromy groups.
  • 2023 Sept. MFO-RIMS Tandem workshop 2023 - Arithmetic Homotopy and Galois Theory, Research Institute for Mathematical Sciences, Japan, Oda's problem for cyclic special loci.
  • 2023 May Séminaire variétés rationelles , Ecole Polytechnique, Palaiseau, France, Degré de semi-stabilité des variétés abéliennes et monodromie finie.
  • 2023 May Number theory seminar , Bordeaux university, Bordeaux, France, Groupes de monodromie finie et variétés abéliennes CM.
  • 2023 Mar. Arithmetic and Homotopic Galois Theory , Hybrid, Paris-Kyoto
  • 2023 Jan. Arithmetic seminar , Université de Lille, Groupes de monodromie finie et variétés abéliennes CM
  • 2022 Nov. 4th Kyoto-Nanjing workshop on Geometry and Arithmetic , Online, Fields of definition of endomorphisms and abelian subvarieties.
  • 2022 Apr. Algebra seminar , Western University (online), Canada, On the degree of semi-stable reduction for abelian varieties.
  • 2021 Nov. Number theory seminar , Clermont-Ferrand, France, Degré de semi-stabilité pour les variétés abéliennes.
  • 2021 Sep. Number theory seminar , Grenoble, France, Groupes de monodromie finie et degré de semi-stabilité pour les variétés abéliennes.
  • 2021 Mar. Homotopic and Geometric Galois Theory , MFO workshop (online), Germany, reporter.
  • 2020 Dec. Copenhagen Number Theory seminar , Copenhagen (online), Denmark The degree of semi-stable reduction.
  • 2020 Dec. RéGA seminar , Paris (online), France, Critères de réduction pour les variétés abéliennes.
  • 2020 Aug. Homotopical arithmetic geometry seminar , Kyoto (online), Japan Good reduction of abelian varieties and Ogg-Néron-Shafarevich criterion.
  • 2020 May Linfoot seminar , University of Bristol (online), United Kingdom, Semi-stable reduction of abelian varieties.
    • Atelier de Géométrie Arithmétique

    I am the main organizer of a Franco-Japanese workshop for young researchers named ''Atelier de Géométrie Arithmétique''. You can find below the webpages, programs and notes from the workshop below.

  • Around the Grothendieck-Teichmuller group. [webpage, program, poster]  

  • Local-global principles and the patching method. [webpage, program, poster, notes]  

    •