activity
20162026
most citedExistence and nonexistence of solutions for the heat equation with a superlinear source term

3 citations · 7 across the 12 of their papers we have counts for

collaborators

14 papers

math.AP2026

Nondegeneracy and asymptotic behavior of type I blow-up for semilinear heat equations with general nonlinearities

Yohei Fujishima, Ryoto Ichiya, Norisuke Ioku

We study the local asymptotic behavior of nonnegative type I blow-up solutions to semilinear heat equations with nonlinearities that need not be scale invariant. Using a quasi-simi…

math.AP2025

Multiplicity of singular solutions for semilinear elliptic equations with superlinear source terms

Yohei Fujishima, Norisuke Ioku

This paper investigates the multiplicity of singular solutions for the nonlinear elliptic equation near the origin. Applying the classification of nonlinear functions a…

math.AP2025

Non-uniqueness of mild solutions for 2d-heat equations with singular initial data

Yohei Fujishima, Norisuke Ioku, Bernhard Ruf +1

In a recent article by the authors [15] it was shown that wide classes of semilinear elliptic equations with exponential type nonlinearities admit singular radial solutions on…

physics.ao-ph2025

Atmospheric Predictability Beyond 30 Days with Machine Learning

P. Trent Vonich, Gregory J. Hakim

Atmospheric predictability research has long held that rapid error growth at small spatial scales imposes an intrinsic limit of roughly two weeks on deterministic weather forecast…

math.AP2024

Uniform boundedness and blow-up rate of solutions in non-scale-invariant superlinear heat equations

Yohei Fujishima, Toru Kan

For superlinear heat equations with the Dirichlet boundary condition, the estimates of radially symmetric solutions are studied. In particular, the uniform boundedness o…

math.AP2024

Existence of solutions for a semilinear parabolic system with singular initial data

Yohei Fujishima, Kazuhiro Ishige, Tatsuki Kawakami

Let be a solution to the Cauchy problem for a semilinear parabolic system \[ \mathrm{(P)} \qquad \cases{ \partial_t u=D_1Δu+v^p\quad & $\quad\mbox{in}\quad{\mathbb{R}}^N\ti…

math.AP2024

Singular solutions of semilinear elliptic equations with exponential nonlinearities in 2-dimensions

Yohei Fujishima, Norisuke Ioku, Bernhard Ruf +1

By introducing a new classification of the growth rate of exponential functions, singular solutions for semilinear elliptic equations in 2-dimensions with exponential nonlinearitie…

math.AP2023

Local solvability and dilation-critical singularities of supercritical fractional heat equations

Yohei Fujishima, Kotaro Hisa, Kazuhiro Ishige +1

We consider the Cauchy problem for fractional semilinear heat equations with supercritical nonlinearities and establish both necessary conditions and sufficient conditions for loca…

math.AP2022

Quasi self-similarity and its application to the global in time solvability of a superlinear heat equation

Yohei Fujishima, Norisuke Ioku

This paper concerns the global in time existence of solutions for a semilinear heat equation \begin{equation} \tag{P} \label{eq:P} \begin{cases} \partial_t u = Δu + f(u), &x\in \ma…

math.AP2022★ 1 cited

Solvability of Superlinear Fractional Parabolic Equations

Yohei Fujishima, Kotaro Hisa, Kazuhiro Ishige +1

We study necessary conditions and sufficient conditions for the existence of local-in-time solutions of the Cauchy problem for superlinear fractional parabolic equations. Our condi…

math.AP2020★ 2 cited

Optimal singularities of initial functions for solvability of a semilinear parabolic system

Yohei Fujishima, Kazuhiro Ishige

Let be a nonnegative solution to the semilinear parabolic system \[ \mbox{(P)} \qquad \cases{ \partial_t u=D_1Δu+v^p, & \\ \partial_t v=D_2Δv+u^q,…

math.AP2019★ 1 cited

Initial traces and solvability of Cauchy problem to a semilinear parabolic system

Yohei Fujishima, Kazuhiro Ishige

Let be a solution to a semilinear parabolic system \[ \mbox{(P)} \qquad \begin{cases} \partial_t u=D_1Δu+v^p\quad & \quad\mbox{in}\quad{\bf R}^N\times(0,T),\\ \partial_t v=…

math.AP2017

Critical exponent for the global existence of solutions to a nonlinear degenerate/singular parabolic equation

Yohei Fujishima, Tatsuki Kawakami, Yannick Sire

We investigate a non-homogeneous nonlinear heat equation which involves degenerate or singular coefficients belonging to the class of functions. We prove the existence of a F…

math.AP2016★ 3 cited

Existence and nonexistence of solutions for the heat equation with a superlinear source term

Yohei Fujishima, Norisuke Ioku

Classification theory on the existence and non-existence of local in time solutions for initial value problems of nonlinear heat equations are investigated. Without assuming a conc…