# Weak-strong uniqueness in fluid dynamics

## TL;DR

This paper surveys recent results on weak-strong uniqueness principles in fluid dynamics, highlighting their significance in understanding non-uniqueness and convergence issues in Euler and Navier-Stokes equations.

## Contribution

It provides a comprehensive overview of recent developments and introduces new insights into weak-strong uniqueness in fluid equations.

## Key findings

- Weak-strong uniqueness holds for certain classes of solutions.
- The principle helps analyze convergence in singular limits.
- New observations extend the understanding of uniqueness in fluid models.

## Abstract

We give a survey of recent results on weak-strong uniqueness for compressible and incompressible Euler and Navier-Stokes equations, and also make some new observations. The importance of the weak-strong uniqueness principle stems, on the one hand, from the instances of non-uniqueness for the Euler equations exhibited in the past years; and on the other hand from the question of convergence of singular limits, for which weak-strong uniqueness represents an elegant tool.