{ "id": "2204.08231", "version": "v1", "published": "2022-04-18T09:34:54.000Z", "updated": "2022-04-18T09:34:54.000Z", "title": "Long-time behaviour and stability for quasilinear doubly degenerate parabolic equations of higher order", "authors": [ "Jonas Jansen", "Christina Lienstromberg", "Katerina Nik" ], "comment": "25 pages, 2 figures", "categories": [ "math.AP" ], "abstract": "We study the long-time behaviour of solutions to quasilinear doubly degenerate parabolic problems of fourth order. The equations model for instance the dynamic behaviour of a non-Newtonian thin-film flow on a flat impermeable bottom and with zero contact angle. We consider a shear-rate dependent fluid the rheology of which is described by a constitutive power-law or Ellis-law for the fluid viscosity. In all three cases, positive constants (i.e. positive flat films) are the only positive steady-state solutions. Moreover, we can give a detailed picture of the long-time behaviour of solutions with respect to the $H^1(\\Omega)$-norm. In the case of shear-thickening power-law fluids, one observes that solutions which are initially close to a steady state, converge to equilibrium in finite time. In the shear-thinning power-law case, we find that steady states are polynomially stable in the sense that, as time tends to infinity, solutions which are initially close to a steady state, converge to equilibrium at rate $1/t^{1/\\beta}$ for some $\\beta > 0$. Finally, in the case of an Ellis-fluid, steady states are exponentially stable in $H^1(\\Omega)$.", "revisions": [ { "version": "v1", "updated": "2022-04-18T09:34:54.000Z" } ], "analyses": { "subjects": [ "76A05", "76A20", "35B40", "35Q35", "35K35", "35K65" ], "keywords": [ "quasilinear doubly degenerate parabolic equations", "long-time behaviour", "steady state", "higher order", "quasilinear doubly degenerate parabolic problems" ], "note": { "typesetting": "TeX", "pages": 25, "language": "en", "license": "arXiv", "status": "editable" } } }