{ "id": "1807.00550", "version": "v1", "published": "2018-07-02T09:14:46.000Z", "updated": "2018-07-02T09:14:46.000Z", "title": "Global Existence of the Compressible Euler Equations with Time-dependent Damping and Sign-changing State Equation", "authors": [ "Ka Luen Cheung", "Sen Wong" ], "categories": [ "math.AP", "math-ph", "math.MP" ], "abstract": "In mathematical physics, the pressure function is determined by the equation of state. There are two existing state equations: the state equation (S+) for polytropic gas with adiabatic index greater than 1 and the state equation (S-) for generalized Chaplygin gas in cosmology. In this paper, we provide some mathematical foundations for the sign-changing pressure (S*) by establishing a global existence result for the one-dimensional Euler equations with time-dependent damping. It is found that the newly introduced sign-changing pressure shares many mathematical properties such as reduction to a symmetric hyperbolic system and finite propagation speed property with the classical positive pressure S+ and the negative pressure S-. Moreover, S+ and S- are unified and generalized in our proposition which includes a global existence result for S+, S- and S*.", "revisions": [ { "version": "v1", "updated": "2018-07-02T09:14:46.000Z" } ], "analyses": { "keywords": [ "compressible euler equations", "sign-changing state equation", "time-dependent damping", "global existence result", "one-dimensional euler equations" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }