activity
20242026
collaborators

11 papers

math.AP2026

Kinetic Fokker-Planck equations with Maxwell boundary conditions

Kyeongbae Kim, Marvin Weidner

We develop the boundary regularity theory for solutions to linear kinetic Fokker-Planck equations with Maxwell boundary conditions. These conditions interpolate between diffuse and…

math.AP2026

Boundary Harnack estimates of optimal order for kinetic Fokker-Planck equations

Kyeongbae Kim, Marvin Weidner

We establish higher order boundary Harnack estimates for solutions to kinetic Fokker-Planck equations with absorbing incoming boundaries. Unlike classical elliptic and parabolic eq…

math.AP2026

Well-Posedness Of Second-Order Evolution Equations With Non-Integrable And Degenerate Coefficients In Weighted Lp-Spaces

Ildoo Kim, Kyeong-Hun Kim

We study the Cauchy problem for inhomogeneous evolution equations with time-dependent, potentially degenerate, and unbounded coefficients. A key feature of our work is allowing the…

math.AP2026

Sharp regularity near the grazing set for kinetic Fokker-Planck equations

Kyeongbae Kim, Marvin Weidner

We prove optimal regularity results for solutions to linear kinetic Fokker-Planck equations in bounded domains. Our contributions are two-fold. First, we establish the sharp $C^{1/…

math.AP2026

Fine regularity of fractional harmonic maps and applications

Kyeongbae Kim, Simon Nowak, Yannick Sire

In this paper, we derive several regularity results for harmonic mappings into Euclidean spheres associated with rather general energies related to fractional Sobolev spaces. These…

math.AP2025

Logarithmic continuity for the Nonlocal degenerate two-phase Stefan problem

Kyeongbae Kim, Ho-Sik Lee, Harsh Prasad

We establish certain oscillation estimates for weak solutions to nonlinear, anomalous phase transitions modeled on the nonlocal two-phase Stefan problem. The problem is singular in…

math.AP2025

Local Hölder Regularity For Nonlocal Porous Media And Fast Diffusion Equations With General Kernel

Kyeongbae Kim, Ho-Sik Lee, Harsh Prasad

We show that locally bounded, local weak solutions to certain nonlocal, nonlinear diffusion equations modeled on the fractional porous media and fast diffusion equations given by \…

math.AP2025

Gradient estimates for nonlinear kinetic Fokker-Planck equations

Kyeongbae Kim, Ho-Sik Lee, Simon Nowak

In this work, we provide a comprehensive gradient regularity theory for a broad class of nonlinear kinetic Fokker-Planck equations. We achieve this by establishing precise pointwis…

math.AP2024

Gradient estimates for parabolic nonlinear nonlocal equations

Lars Diening, Kyeongbae Kim, Ho-Sik Lee +1

The primary objective of this work is to establish pointwise gradient estimates for solutions to a class of parabolic nonlinear nonlocal measure data problems, expressed in terms o…

math.AP2024

Higher differentiability for the fractional -Laplacian

Lars Diening, Kyeongbae Kim, Ho-Sik Lee +1

In this work, we study the higher differentiability of solutions to the inhomogeneous fractional -Laplace equation under different regularity assumptions on the data. In the sup…

math.AP2024

Nonlinear nonlocal potential theory at the gradient level

Lars Diening, Kyeongbae Kim, Ho-Sik Lee +1

The aim of this work is to establish numerous interrelated gradient estimates in the nonlinear nonlocal setting. First of all, we prove that weak solutions to a class of homogeneou…