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Studies on the thoery of elliptic operators with unbounded coefficients and applications

Research Project

Project/Area Number 18K13445
Research Category

Grant-in-Aid for Early-Career Scientists

Allocation TypeMulti-year Fund
Review Section Basic Section 12020:Mathematical analysis-related
Research InstitutionTokyo University of Science

Principal Investigator

Sobajima Motohiro  東京理科大学, 理工学部数学科, 講師 (20760367)

Project Period (FY) 2018-04-01 – 2022-03-31
Project Status Completed (Fiscal Year 2021)
Budget Amount *help
¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000)
Fiscal Year 2021: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2020: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2019: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2018: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Keywords非有界な係数をもつ楕円型作用素 / 消散型波動方程式 / 漸近展開 / 高次漸近展開 / 半線形熱方程式系 / 特異極限 / 波動方程式 / Rellichの不等式 / 非線形消散型波動方程式 / 非線形波動方程式 / 外部問題
Outline of Final Research Achievements

In this research, we focus our attention to the development and applications to the theory of second order elliptic operators with unbounded coefficients. In the flamework of partial differential differential equations, we try to find essentials of linear problems and to apply it to the corresponding nonlinear problems.
One of the achievement in the linear problem is the Rellich inequalities in bounded domains. We found the necessary and sufficient conditions on the validity of Rellich inequalities with the Laplacian perturbed by the singular lower order terms.
For the nonlinear problem, we discussed the large time behavior of solutions to linear wave equations with space-dependent damping terms, blowup phenomena and global existence for the corresponding nonlinear problems.

Academic Significance and Societal Importance of the Research Achievements

非有界な係数をもつ2階楕円型作用素は様々な自然現象を記述する際に用いられる。この研究で、空間変数に依存する消散型波動方程式の長時間挙動に非有界な拡散構造を見ることができた。これは既存の研究からは得られない知見であり、同種の現象が他のモデルにも内在する可能性を示唆している。このことから、今後さらに非有界な係数という枠組みの重要性が高まったと考えている。

Report

(5 results)
  • 2021 Annual Research Report   Final Research Report ( PDF )
  • 2020 Research-status Report
  • 2019 Research-status Report
  • 2018 Research-status Report
  • Research Products

    (29 results)

All 2022 2021 2020 2019 2018

All Journal Article (14 results) (of which Int'l Joint Research: 1 results,  Peer Reviewed: 14 results) Presentation (15 results) (of which Int'l Joint Research: 1 results,  Invited: 13 results)

  • [Journal Article] Singular limit problem of abstract second order evolution equations2022

    • Author(s)
      Motohiro Sobajima, Ryo Ikehata
    • Journal Title

      Hokkaido Mathematical Journal

      Volume: -

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed
  • [Journal Article] On global existence for semilinear wave equations with space-dependent critical damping2022

    • Author(s)
      Motohiro Sobajima
    • Journal Title

      Journal of the Mathematical Society of Japan

      Volume: -

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Higher-order asymptotic expansion for abstract linear second-order differential equations with time-dependent coefficients2022

    • Author(s)
      Sobajima Motohiro
    • Journal Title

      Journal of Differential Equations

      Volume: 327 Pages: 226-258

    • DOI

      10.1016/j.jde.2022.04.024

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Global existence of solutions to a weakly coupled critical parabolic system in two-dimensional exterior domains2021

    • Author(s)
      Sobajima Motohiro
    • Journal Title

      Journal of Mathematical Analysis and Applications

      Volume: 501 Issue: 2 Pages: 125214-125214

    • DOI

      10.1016/j.jmaa.2021.125214

    • Related Report
      2020 Research-status Report
    • Peer Reviewed
  • [Journal Article] Blow-up for Strauss type wave equation with damping and potential2021

    • Author(s)
      Dai Wei、Kubo Hideo、Sobajima Motohiro
    • Journal Title

      Nonlinear Analysis: Real World Applications

      Volume: 57 Pages: 103195-103195

    • DOI

      10.1016/j.nonrwa.2020.103195

    • Related Report
      2020 Research-status Report
    • Peer Reviewed
  • [Journal Article] Supersolutions for parabolic equations with unbounded or degenerate diffusion coefficients and their applications to some classes of parabolic and hyperbolic equations2021

    • Author(s)
      SOBAJIMA Motohiro、WAKASUGI Yuta
    • Journal Title

      Journal of the Mathematical Society of Japan

      Volume: 73 Issue: 4 Pages: 1091-1128

    • DOI

      10.2969/jmsj/83928392

    • NAID

      130008106924

    • ISSN
      0025-5645, 1881-1167, 1881-2333
    • Related Report
      2020 Research-status Report
    • Peer Reviewed
  • [Journal Article] Remark on one dimensional semilinear damped wave equation in a critical weighted L^2-space2021

    • Author(s)
      Motohiro Sobajima, Yuta Wakasugi
    • Journal Title

      Geometric Properties for Parabolic and Elliptic PDEs

      Volume: -

    • Related Report
      2020 Research-status Report
    • Peer Reviewed
  • [Journal Article] Lifespan of solutions to nonlinear Schr\"odinger equations with general homogeneous nonlinearity of the critical order2020

    • Author(s)
      Hayato Miyazaki, Motohiro Sobajima
    • Journal Title

      Advances in Harmonic Analysis and Partial Differential Equations

      Volume: - Pages: 197-207

    • Related Report
      2020 Research-status Report
    • Peer Reviewed
  • [Journal Article] Finite time blowup of solutions to semilinear wave equation in an exterior domain2020

    • Author(s)
      Motohiro Sobajima, Kyouhei Wakasa
    • Journal Title

      Journal of Mathematical Analysis and Applications

      Volume: 484 Issue: 1 Pages: 123667-123667

    • DOI

      10.1016/j.jmaa.2019.123667

    • Related Report
      2019 Research-status Report
    • Peer Reviewed
  • [Journal Article] Rellich inequalities in bounded domains2020

    • Author(s)
      Giorgio Metafune, Luigi Negro, Motohiro Sobajima, Chiara Spina
    • Journal Title

      Mathematische Annalen

      Volume: 印刷中 Issue: 1-2 Pages: 765-824

    • DOI

      10.1007/s00208-019-01947-9

    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Higher order asymptotic expansion of solutions to abstract linear hyperbolic equations2020

    • Author(s)
      Motohiro Sobajima
    • Journal Title

      Mathematische Annalen

      Volume: 印刷中 Issue: 1-2 Pages: 1-19

    • DOI

      10.1007/s00208-020-01959-w

    • Related Report
      2019 Research-status Report
    • Peer Reviewed
  • [Journal Article] Sharp lifespan estimates of blowup solutions to semi-linear wave equations with time-dependent effective damping2019

    • Author(s)
      Ikeda Masahiro、Sobajima Motohiro、Wakasugi Yuta
    • Journal Title

      Journal of Hyperbolic Differential Equations

      Volume: 16 Issue: 03 Pages: 495-517

    • DOI

      10.1142/s0219891619500176

    • Related Report
      2019 Research-status Report
    • Peer Reviewed
  • [Journal Article] Global existence of solutions to semilinear damped wave equation with slowly decaying inital data in exterior domain2019

    • Author(s)
      Motohiro Sobajima
    • Journal Title

      Differential and Integral Equations

      Volume: 32 Pages: 615-638

    • Related Report
      2019 Research-status Report
    • Peer Reviewed
  • [Journal Article] Critical exponent for the semilinear wave equations with a damping increasing in the far field2018

    • Author(s)
      Nishihara Kenji、Sobajima Motohiro、Wakasugi Yuta
    • Journal Title

      Nonlinear Differential Equations and Applications NoDEA

      Volume: 25 Issue: 6

    • DOI

      10.1007/s00030-018-0546-2

    • Related Report
      2018 Research-status Report
    • Peer Reviewed
  • [Presentation] Weighted energy estimates for wave equations with space-dependent damping2022

    • Author(s)
      側島 基宏
    • Organizer
      日本数学会2022年度年会 函数方程式論分科会
    • Related Report
      2021 Annual Research Report
    • Invited
  • [Presentation] 消散型波動方程式に関連する特異極限問題について2021

    • Author(s)
      側島 基宏
    • Organizer
      熊本大学応用解析セミナー
    • Related Report
      2021 Annual Research Report
    • Invited
  • [Presentation] On asymptotic expansion for solutions of damped wave equations in exterior domains2021

    • Author(s)
      Motohiro Sobajima
    • Organizer
      第12回 名古屋微分方程式研究集会
    • Related Report
      2020 Research-status Report
    • Invited
  • [Presentation] Higher order asymptotic expansion for abstract linear hyperbolic equations2020

    • Author(s)
      Motohiro Sobajima
    • Organizer
      第21 回北東研究会
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] Global existence for a critical weakly coupled parabolic system in 2d-exterior domain2019

    • Author(s)
      Motohiro Sobajima
    • Organizer
      the VI Italian-Japanese Workshop “Geometric properties for parabolic and elliptic PDE’s
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] On test function methods for nonlinear wave equations2019

    • Author(s)
      Motohiro Sobajima
    • Organizer
      三重偏微分方程式研究集会
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] Semilinear damped wave equation with slowly decaying initial data in exterior domain2019

    • Author(s)
      Motohiro Sobajima
    • Organizer
      北海道大学偏微分方程式セミナー
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] Finite time blowup of solutions to semilinear wave equation in an exterior domain2019

    • Author(s)
      Motohiro Sobajima
    • Organizer
      The 17th Linear and Nonlinear Waves
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] On test function method for semilinear wave equations with scale-invariant damping2019

    • Author(s)
      Motohiro Sobajima
    • Organizer
      RIMS 共同研究(公開型)「常微分方程式における最近の動向とその発展」
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] あるクラスの非有界な係数をもつSchr¨odinger 作用素の自己共役性について2019

    • Author(s)
      Motohiro Sobajima
    • Organizer
      静岡複素解析幾 何セミナー
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] Global existence of solutions to semilinear damped wave equation with slowly decaying initial data in exterior domain2019

    • Author(s)
      Motohiro Sobajima
    • Organizer
      Workshop on PDEs in Direct and Inverse Problems 2019
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] On blowup solutions of semilinear wave equations and their weakly coupled systems2019

    • Author(s)
      Masahiro Ikeda, Motohiro Sobajima, Kyouhei
    • Organizer
      日本数学会2018年度年会函数方程式論分科会
    • Related Report
      2018 Research-status Report
  • [Presentation] Critical exponent for the semilinear wave equations with a damping increasing in the far field2019

    • Author(s)
      Kenji Nishihara, Motohiro Sobajima, Yuta Wakasugi
    • Organizer
      日本数学会2018年度年会函数方程式論分科会
    • Related Report
      2018 Research-status Report
  • [Presentation] Remark on lifespan estimates for semilinear wave equations and their weakly coupled systems2018

    • Author(s)
      Motohiro Sobajima
    • Organizer
      One-day workshop on nonlinear dispersive equations in Osaka
    • Related Report
      2018 Research-status Report
    • Invited
  • [Presentation] On blowup phenomena of semilinear wave equations and their weakly coupled systems2018

    • Author(s)
      Motohiro Sobajima
    • Organizer
      第8回 弘前非線形方程式研究会
    • Related Report
      2018 Research-status Report
    • Invited

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Published: 2018-04-23   Modified: 2023-01-30  

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