{ "id": "2408.09514", "version": "v1", "published": "2024-08-18T15:39:59.000Z", "updated": "2024-08-18T15:39:59.000Z", "title": "Regularity Propagation of Global Weak Solutions to a Navier-Stokes-Cahn-Hilliard System for Incompressible Two-phase Flows with Chemotaxis and Active Transport", "authors": [ "Jingning He", "Hao Wu" ], "categories": [ "math.AP" ], "abstract": "We analyze a diffuse interface model that describes the dynamics of incompressible viscous two-phase flows, incorporating mechanisms such as chemotaxis, active transport, and long-range interactions of Oono's type. The evolution system couples the Navier-Stokes equations for the volume-averaged fluid velocity $\\bm{v}$, a convective Cahn-Hilliard equation for the phase-field variable $\\varphi$, and an advection-diffusion equation for the density of a chemical substance $\\sigma$. For the initial-boundary value problem with a physically relevant singular potential in three dimensions, we demonstrate that every global weak solution $(\\bm{v}, \\varphi, \\sigma)$ exhibits a propagation of regularity over time. Specifically, after an arbitrary positive time, the phase-field $\\varphi$ transitions into a strong solution, whereas the chemical density $\\sigma$ only partially regularizes. Subsequently, the velocity field $\\bm{v}$ becomes regular after a sufficiently large time, followed by a further regularization of the chemical density $\\sigma$, which in turn enhances the spatial regularity of $\\varphi$. Furthermore, we show that every global weak solution stabilizes towards a single equilibrium as $t\\to +\\infty$. Our analysis uncovers the influence of chemotaxis, active transport, and long-range interactions on the propagation of regularity at different stages of time. The proof relies on several key points, including a novel regularity result for a convective Cahn-Hilliard-diffusion system with minimal regularity requirements on the velocity field $\\bm{v}$, the strict separation property of $\\varphi$ for large times, as well as two conditional uniqueness results pertaining to the full system and its subsystem for $(\\varphi, \\sigma)$ with a given velocity, respectively.", "revisions": [ { "version": "v1", "updated": "2024-08-18T15:39:59.000Z" } ], "analyses": { "subjects": [ "35A01", "35A02", "35K35", "35Q92", "76D05" ], "keywords": [ "incompressible two-phase flows", "active transport", "regularity propagation", "navier-stokes-cahn-hilliard system", "chemotaxis" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }