collaborators

6 papers

math.AP2026

The local least action criterion fails as a selection criterion for weak solutions of the compressible Euler equations

Simon Markfelder, Valentin Pellhammer

It is now well known that the classical notion of admissible weak solutions (also known as weak entropy solutions) does not restore uniqueness for the multi-dimensional compressibl…

math.AP2026

Non-uniqueness of global-in-time admissible weak solutions to the isentropic compressible Euler equations for a dense set of initial data

Daniel W. Boutros, Simon Markfelder

In recent years, the technique of convex integration has demonstrated that for some initial data (also referred to as 'wild initial data'), many PDE models of mathematical fluid me…

math.AP2026

A Generalized Framework for Convex Integration and its Application to Geophysical Models

Daniel W. Boutros, Simon Markfelder, Edriss S. Titi

In this paper a general framework for convex integration is developed, in order to construct weak solutions to the Cauchy problem, by building on ideas from [C. De Lellis and L. Sz…

math.AP2026

Maximal entropy production principle and the Euler system of gas dynamics

Elisabetta Chiodaroli, Eduard Feireisl, Ondřej Kreml +1

Convex integration has revealed that the Euler system of gas dynamics is ill-posed in the class of weak solutions even if the entropy inequality is imposed as an additional constra…

math.AP2026

Maximal turbulence as a selection criterion for measure-valued solutions

Christian Klingenberg, Simon Markfelder, Emil Wiedemann

The quest for a good solution concept for the partial differential equations (PDEs) arising in mathematical fluid dynamics is an outstanding open problem. An important notion of so…

math.AP2025

Failure of the least action admissibility principle in the context of the compressible Euler equations

Simon Markfelder, Valentin Pellhammer

Finding a proper solution concept for the multi-dimensional barotropic compressible Euler equations and related systems is still an unsolved problem. As revealed by convex integrat…