# Global existence in critical spaces for non Newtonian compressible viscoelastic flows

## TL;DR

This paper proves the global existence of strong solutions for multi-dimensional compressible viscoelastic flows of Oldroyd type in critical spaces without structural conditions, introducing effective flux to handle partial dissipation.

## Contribution

It removes the structural condition requirement and introduces effective flux to establish global solutions in critical spaces for non-Newtonian compressible viscoelastic flows.

## Key findings

- Proved global existence of strong solutions in critical spaces.
- Introduced effective flux to handle partial dissipation.
- Achieved results without structural conditions.

## Abstract

We are interested in the multi-dimentional compressible viscoelastic flows of Oldroyd type, which is one of non-Newtonian fluids exhibiting the elastic behavior. In order to capture the damping effect of the additional deformation tensor, to the best of our knowledge, the "div-curl" structural condition plays a key role in previous efforts. Our aim of this paper is to remove the structural condition and prove a global existence of strong solutions to compressible viscoelastic flows in critical spaces. The new ingredient lies in the introduction of effective flux $(\theta,\mathcal{G})$, which enables us to capture the dissipation arising from \textit{combination} of density and deformation tensor. In absence of compatible conditions, the partial dissipation is found in non-Newtonian compressible fluids, which is weaker than that of usual Navier-Stokes equations.