{ "id": "2103.04905", "version": "v1", "published": "2021-03-08T17:09:44.000Z", "updated": "2021-03-08T17:09:44.000Z", "title": "Global ill-posedness for a dense set of initial data to the Isentropic system of gas dynamics", "authors": [ "Robin Ming Chen", "Alexis F. Vasseur", "Cheng Yu" ], "comment": "1 figure", "categories": [ "math.AP" ], "abstract": "In dimension $n=2$ and $3$, we show that for any initial datum belonging to a dense subset of the energy space, there exist infinitely many global-in-time admissible weak solutions to the isentropic Euler system whenever $1<\\gamma\\leq 1+\\frac2n$. This result can be regarded as a compressible counterpart of the one obtained by Szekelyhidi--Wiedemann (ARMA, 2012) for incompressible flows. Similarly to the incompressible result, the admissibility condition is defined in its integral form. Our result is based on a generalization of a key step of the convex integration procedure. This generalization allows, even in the compressible case, to convex integrate any smooth positive Reynolds stress. A large family of subsolutions can then be considered. These subsolutions can be generated, for instance, via regularization of any weak inviscid limit of an associated compressible Navier--Stokes system with degenerate viscosities.", "revisions": [ { "version": "v1", "updated": "2021-03-08T17:09:44.000Z" } ], "analyses": { "subjects": [ "35Q31", "76N10", "35L65" ], "keywords": [ "initial datum", "global ill-posedness", "gas dynamics", "isentropic system", "dense set" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }