activity
20162025
collaborators

19 papers

math.AP2025

Stochastic perturbation and zero noise limit for scalar conservation laws

Ulrik S. Fjordholm, Magnus C. Ørke

Scalar conservation laws sit at the intersection between being simple enough to study analytically, while being complex enough to exhibit a wide range of nonlinear phenomena. We in…

math.NA2025

Semi-discrete heat equations with variable coefficients and the parametrix method

Ulrik S. Fjordholm, Kenneth H. Karlsen, Peter H. C. Pang

We develop a parametrix approach for constructing solutions and establishing grid-size independent estimates for semi-discrete heat equations with variable coefficients. While the…

math.AP2025

Transport equations for Osgood velocity fields

Ulrik Skre Fjordholm, Ola Isaac Høgåsen Mæhlen

We consider the transport equation with a velocity field satisfying the Osgood condition. The weak formulation is not meaningful in the usual Lebesgue sense, meaning that the usual…

math.NA2023

Convergent finite difference schemes for stochastic transport equations

Ulrik S. Fjordholm, Kenneth H. Karlsen, Peter H. C. Pang

We present difference schemes for stochastic transport equations with low-regularity velocity fields. We establish stability and convergence of the difference approximations…

math.AP2023

The particle paths of hyperbolic conservation laws

Ulrik S. Fjordholm, Ola H. Mæhlen, Magnus C. Ørke

Nonlinear scalar conservation laws are traditionally viewed as transport equations. We take instead the viewpoint of these PDEs as continuity equations with an implicitly defined v…

math.PR2022

The zero-noise limit of SDEs with drift

Ulrik Skre Fjordholm, Markus Musch, Andrey Pilipenko

We study the zero-noise limit for autonomous, one-dimensional ordinary differential equations with discontinuous right-hand sides. Although the deterministic equation might have in…