{ "id": "2008.07756", "version": "v1", "published": "2020-08-18T06:16:28.000Z", "updated": "2020-08-18T06:16:28.000Z", "title": "Singularity formation for compressible Euler equations with time-dependent damping", "authors": [ "Ying Sui", "Huimin Yu" ], "comment": "19 pages", "categories": [ "math.AP" ], "abstract": "In this paper, we consider the compressible Euler equations with time-dependent damping \\frac{\\a}{(1+t)^\\lambda}u in one space dimension. By constructing 'decoupled' Riccati type equations for smooth solutions, we provide some sufficient conditions under which the classical solutions must break down in finite time. As a byproduct, we show that the derivatives blow up, somewhat like the formation of shock wave, if the derivatives of initial data are appropriately large at a point even when the damping coefficient goes to infinity with a algebraic growth rate. We study the case \\lambda\\neq1 and \\lambda=1 respectively, moreover, our results have no restrictions on the size of solutions and the positivity/monotonicity of the initial Riemann invariants. In addition, for 1<\\gamma<3 we provide time-dependent lower bounds on density for arbitrary classical solutions, without any additional assumptions on the initial data.", "revisions": [ { "version": "v1", "updated": "2020-08-18T06:16:28.000Z" } ], "analyses": { "subjects": [ "35Q05", "76L05", "G.0.0" ], "keywords": [ "compressible euler equations", "time-dependent damping", "singularity formation", "initial data", "riccati type equations" ], "note": { "typesetting": "TeX", "pages": 19, "language": "en", "license": "arXiv", "status": "editable" } } }