5,618 research outputs found

    Coalescence in the 1D Cahn-Hilliard model

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    We present an approximate analytical solution of the Cahn-Hilliard equation describing the coalescence during a first order phase transition. We have identified all the intermediate profiles, stationary solutions of the noiseless Cahn-Hilliard equation. Using properties of the soliton lattices, periodic solutions of the Ginzburg-Landau equation, we have construct a family of ansatz describing continuously the processus of destabilization and period doubling predicted in Langer's self similar scenario

    Global solvability and blow up for the convective Cahn-Hilliard equations with concave potentials

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    We study initial boundary value problems for the convective Cahn-Hilliard equation \Dt u +\px^4u +u\px u+\px^2(|u|^pu)=0. It is well-known that without the convective term, the solutions of this equation may blow up in finite time for any p>0p>0. In contrast to that, we show that the presence of the convective term u\px u in the Cahn-Hilliard equation prevents blow up at least for 0<p<490<p<\frac49. We also show that the blowing up solutions still exist if pp is large enough (p≥2p\ge2). The related equations like Kolmogorov-Sivashinsky-Spiegel equation, sixth order convective Cahn-Hilliard equation, are also considered

    Weak Solutions to the Degenerate Viscous Cahn-Hilliard Equation

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    The Cahn--Hilliard equation is a common model to describe phase separation processes of a mixture of two components. In this paper, we study the viscous Cahn--Hilliard equation with degenerate phase-dependent mobility. We define a notion of weak solutions and prove the existence of such weak solutions by considering the limits of the viscous Cahn--Hilliard equation with positive mobility. Also, we prove that such weak solutions satisfy an energy dissipation inequality under some additional conditions

    On a Cahn-Hilliard system with convection and dynamic boundary conditions

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    This paper deals with an initial and boundary value problem for a system coupling equation and boundary condition both of Cahn-Hilliard type; an additional convective term with a forced velocity field, which could act as a control on the system, is also present in the equation. Either regular or singular potentials are admitted in the bulk and on the boundary. Both the viscous and pure Cahn-Hilliard cases are investigated, and a number of results is proven about existence of solutions, uniqueness, regularity, continuous dependence, uniform boundedness of solutions, strict separation property. A complete approximation of the problem, based on the regularization of maximal monotone graphs and the use of a Faedo-Galerkin scheme, is introduced and rigorously discussed.Comment: Key words: Cahn-Hilliard system, convection, dynamic boundary condition, initial-boundary value problem, well-posedness, regularity of solution

    From the viscous Cahn-Hilliard equation to a regularized forward-backward parabolic equation

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    A rigorous proof is given for the convergence of the solutions of a viscous Cahn-Hilliard system to the solution of the regularized version of the forward-backward parabolic equation, as the coefficient of the diffusive term goes to 0. Non-homogenous Neumann boundary condition are handled for the chemical potential and the subdifferential of a possible non-smooth double-well functional is considered in the equation. An error estimate for the difference of solutions is also proved in a suitable norm and with a specified rate of convergence.Comment: Key words and phrases: Cahn-Hilliard system, forward-backward parabolic equation, viscosity, initial-boundary value problem, asymptotic analysis, well-posednes

    On a Cahn--Hilliard--Darcy system for tumour growth with solution dependent source terms

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    We study the existence of weak solutions to a mixture model for tumour growth that consists of a Cahn--Hilliard--Darcy system coupled with an elliptic reaction-diffusion equation. The Darcy law gives rise to an elliptic equation for the pressure that is coupled to the convective Cahn--Hilliard equation through convective and source terms. Both Dirichlet and Robin boundary conditions are considered for the pressure variable, which allows for the source terms to be dependent on the solution variables.Comment: 18 pages, changed proof from fixed point argument to Galerkin approximatio
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