Skip to main content

and
  1. Article

    Open Access

    Saddle-Type Blow-Up Solutions with Computer-Assisted Proofs: Validation and Extraction of Global Nature

    In this paper, blow-up solutions of autonomous ordinary differential equations (ODEs) which are unstable under perturbations of initial points, referred to as saddle-type blow-up solutions, are studied. Combining...

    Jean-Philippe Lessard, Kaname Matsue, Akitoshi Takayasu in Journal of Nonlinear Science (2023)

  2. Article

    Open Access

    Complex moment-based methods for differential eigenvalue problems

    This paper considers computing partial eigenpairs of differential eigenvalue problems (DEPs) such that eigenvalues are in a certain region on the complex plane. Recently, based on a “solve-then-discretize” par...

    Akira Imakura, Keiichi Morikuni, Akitoshi Takayasu in Numerical Algorithms (2023)

  3. Article

    Open Access

    Correction to: Rigorous numerics for nonlinear heat equations in the complex plane of time

    Akitoshi Takayasu, Jean-Philippe Lessard, Jonathan Jaquette in Numerische Mathematik (2022)

  4. Article

    Open Access

    Rigorous numerics for nonlinear heat equations in the complex plane of time

    In this paper, we introduce a method for computing rigorous local inclusions of solutions of Cauchy problems for nonlinear heat equations for complex time values. The proof is constructive and provides explici...

    Akitoshi Takayasu, Jean-Philippe Lessard, Jonathan Jaquette in Numerische Mathematik (2022)

  5. No Access

    Article

    Numerical validation of blow-up solutions with quasi-homogeneous compactifications

    We provide a numerical validation method of blow-up solutions for finite dimensional vector fields admitting asymptotic quasi-homogeneity at infinity. Our methodology is based on quasi-homogeneous compactifica...

    Kaname Matsue, Akitoshi Takayasu in Numerische Mathematik (2020)

  6. No Access

    Article

    Rigorous numerical computations for 1D advection equations with variable coefficients

    This paper provides a methodology of verified computing for solutions to 1D advection equations with variable coefficients. The advection equation is typical partial differential equations (PDEs) of hyperbolic...

    Akitoshi Takayasu, Suro Yoon, Yasunori Endo in Japan Journal of Industrial and Applied Ma… (2019)

  7. No Access

    Article

    Verified norm estimation for the inverse of linear elliptic operators using eigenvalue evaluation

    This paper proposes a verified numerical method of proving the invertibility of linear elliptic operators. This method also provides a verified norm estimation for the inverse operators. This type of estimatio...

    Kazuaki Tanaka, Akitoshi Takayasu in Japan Journal of Industrial and Applied Ma… (2014)