Updated on 2026/08/04

写真a

 
OSUGA Kento
 
Organization
Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI) Assistant Professor
Graduate School
Graduate School of Mathematics
Title
Assistant Professor
External link

Research Areas 1

  1. Natural Science / Geometry

 

Papers 5

  1. Refined lattice point counting on the moduli space of Klein surfaces Open Access

    Nitin Kumar Chidambaram, Elba Garcia-Failde, Alessandro Giacchetto, Kento Osuga

        2026.5

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    We introduce the moduli space of metric Möbius graphs, which extend ribbon graphs to the non-orientable world. This space contains both the moduli space of Riemann surfaces and the moduli space of non-orientable Klein surfaces. Each metric Möbius graph is equipped with a measure of non-orientability. We count lattice points in this moduli space, weighted by the measure of non-orientability, and prove a refined version of Norbury's recursion for this count. Taking the limit as the mesh becomes finer, we deduce a recursion for the Euclidean volumes, yielding a refined version of the Witten--Kontsevich recursion. As an application, we give a geometric definition of the refined Euler characteristic of the moduli space and compute it explicitly, thereby answering a question of Goulden, Harer, and Jackson.

    DOI: 10.48550/arXiv.2605.09526

    Open Access

    arXiv

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    Other Link: https://arxiv.org/pdf/2605.09526v1

  2. b-Hurwitz numbers from refined topological recursion Open Access

    Nitin Kumar Chidambaram, Maciej Dolega, Kento Osuga

    MATHEMATISCHE ANNALEN   Vol. 394 ( 4 )   2026.3

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1007/s00208-026-03418-4

    Open Access

    Web of Science

    arXiv

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    Other Link: https://arxiv.org/pdf/2412.17502v2

  3. Volumes of moduli spaces of bordered Klein surfaces Open Access

    Elba Garcia-Failde, Paolo Gregori, Kento Osuga

        2025.11

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    We generalise Mirzakhani's recursion to volumes of moduli spaces of bordered Klein surfaces, which include non-orientable surfaces. On these moduli spaces, the top form introduced by Norbury diverges as the lengths of 1-sided geodesics approach zero. However, when integrated over Gendulphe's regularised moduli space, on which the systole of 1-sided geodesics is bounded below by $ε\in\mathbb{R}_{>0}$, it returns a finite value. Using Norbury's extension of the Mirzakhani--McShane identities to non-orientable surfaces, we derive an explicit formula for the volume of the moduli space of one-bordered Klein bottles, as well as a recursion for arbitrary topologies that fully captures the dependence on Gendulphe's regularisation parameter $ε$. We further relate these results to refined topological recursion, showing that, for a fixed refinement parameter, the volumes of moduli spaces of Klein surfaces with Euler characteristic $-1$ are governed by this procedure, and we conjecture the same holds for general topologies.

    DOI: 10.48550/arXiv.2511.21986

    Open Access

    arXiv

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    Other Link: https://arxiv.org/pdf/2511.21986v1

  4. Superconformal topological recursion Open Access

    Nezhla Aghaei, Reinier Kramer, Nicolas Orantin, Kento Osuga

        2025.11

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    We investigate a supersymmetric generalisation of topological recursion from two perspectives: algebraic and geometric. The algebraic side concerns a recursive structure encoded in modules of a super Virasoro algebra, and the geometric counterpart is what we call superconformal topological recursion defined on a super Riemann surface. Superconformal topological recursion indicates that odd holomorphic one-forms on a super Riemann surface are related to zero modes of copies of the Clifford algebras, and it also provides a tool to study deformation of non-split super Riemann surfaces, e.g. certain families of super Riemann surfaces carrying odd parameters. On a super Riemann surface over a non-reduced base, the formalism is recursive not only in terms of pants-decomposition but also in terms of odd parameters in a suitable sense.

    DOI: 10.48550/arXiv.2511.17320

    Open Access

    arXiv

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    Other Link: https://arxiv.org/pdf/2511.17320v1

  5. Refined BPS Structures and Topological Recursion-the Weber and Whittaker Curves Open Access

    Omar Kidwai, Kento Osuga

    INTERNATIONAL MATHEMATICS RESEARCH NOTICES   Vol. 2025 ( 10 )   2025.5

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1093/imrn/rnaf116

    Open Access

    Web of Science

    arXiv

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    Other Link: https://arxiv.org/pdf/2311.17046v1

KAKENHI (Grants-in-Aid for Scientific Research) 4

  1. Refinement of Weil-Petersson Volumes

    Grant number:26K16980  2026.4 - 2029.3

    日本学術振興会  科学研究費助成事業  若手研究

    大須賀 けん斗

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  2. Topological recursion, quantum curves and resurgence theory

    Grant number:24K00525  2024.4 - 2029.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

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  3. Refinement and q-deformation of topological recursion and their applications

    Grant number:23K12968  2023.4 - 2026.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Early-Career Scientists

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    Authorship:Principal investigator 

    Grant amount:\4550000 ( Direct Cost: \3500000 、 Indirect Cost:\1050000 )

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  4. Super Quantum Curves and Super Voros Coefficients

    Grant number:22KJ0715  2023.3 - 2025.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for JSPS Fellows

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    Authorship:Principal investigator 

    Grant amount:\4420000 ( Direct Cost: \3400000 、 Indirect Cost:\1020000 )

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