Generalized solvability and optimization of a parabolic system with a discontinuous solution

We consider the following linear parabolic system in a domain with a thin low-permeable insertion (“imperfect interface”):

     

Error estimates for discontinuous Galerkin method for nonlinear parabolic equations

We consider the nonlinear parabolic partial differential equations. We construct a discontinuous Galerkin approximation using a penalty term and obtain an optimal L^∞(L²) error estimate.     

A pathwise solution for nonlinear parabolic equations with stochastic perturbations

We analyse here a semilinear stochastic partial differential equation of parabolic type where the diffusion vector fields are depending on both the unknown function and its gradient ∂ _xu with respect to the state variable, ∈ ℝⁿ. A local solution is constructed by reducing the original equation to a nonlinear parabolic one without stochastic perturbations and it is based on a finite dimensional Lie algebra generated by the given diffusion vector fields.     

An approximate solution for nonlinear backward parabolic equations

We consider the backward parabolic equation

     

Fully discrete interior penalty discontinuous Galerkin methods for nonlinear parabolic equations

In this article, we investigate interior penalty discontinuous Galerkin (IPDG) methods for solving a class of two‐dimensional nonlinear parabolic equations. For semi‐discrete IPDG schemes on a quasi‐uniform family of meshes, we obtain a priori bounds on solutions measured in the L² norm and in the broken Sobolev norm. The fully discrete IPDG schemes considered are based on the approximation by forward Euler difference in time and broken Sobolev space. Under a restriction related to the mesh size and time step, an hp ‐version of an a priori l^∞(L²) and l²(H¹) error estimate is derived and numerical experiments are presented.© 2010 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 28: 288–311, 2012     

Finite-element discretization of a parabolic equation with a discontinuous solution

Convergence of the approximate solution is proved. Numerical solutions of some examples are given.Kiev University. Translated from Vychislitel'naya i Prikladnaya Matematika, No. 68, pp. 77–85, 1989.     

Numerical solution of parabolic integro-differential equations by the discontinuous Galerkin method

The numerical solution of a parabolic equation with memory is considered. The equation is first discretized in time by means of the discontinuous Galerkin method with piecewise constant or piecewise linear approximating functions. The analysis presented allows variable time steps which, as will be shown, can then efficiently be selected to match singularities in the solution induced by singularities in the kernel of the memory term or by nonsmooth initial data. The combination with finite element discretization in space is also studied.

     

Classical solvability of a parabolic system of two nonlinear equations

We study the complete regularity of solutions of a nondiagonal parabolic system of quasilinear second-order differential equations in divergence form assuming that the coefficients are sufficiently slowly varying functions of their arguments and the off-diagonal terms in the coefficient matrix are sufficiently small. To this end, we use a method based on the successive approximation to the solution by smooth functions with the use of Schauder estimates at each step.     

Uniqueness for second-order parabolic equations with discontinuous coefficients

We prove uniqueness of the good solution to the Cauchy–Dirichlet (C–D) problem for linear non-variational parabolic equations with the coefficients of the principal part with discountinuities, in cases in which in general uniqueness of strong solutions in Sobolev spaces does not hold. In particular, we prove uniqueness when the discontinuities of the coefficients are contained in a hyperplane t = t ₀ and, with an extra condition on the eigenvalues of the matrix, in a line segment x = x ₀. Mathematics Subject Classification. 35A05, 35K10, 35K20 Dedicated to the memory of Gene Fabes.     

Uniqueness of numerical solutions to nonlinear parabolic equations by a fully implicit discontinuous Galerkin method

We prove uniqueness of numerical solutions to nonlinear parabolic equations approximated by a fully implicit interior penalty discontinuous Galerkin (IPDG) method, with a mesh-independent constraint on time step.     

The probability approach to numerical solution of nonlinear parabolic equations

A number of new layer methods for solving semilinear parabolic equations and reaction‐diffusion systems is derived by using probabilistic representations of their solutions. These methods exploit the ideas of weak sense numerical integration of stochastic differential equations. In spite of the probabilistic nature these methods are nevertheless deterministic. A convergence theorem is proved. Some numerical tests are presented. © 2002 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 18: 490–522, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/num.10020     

Global solution for fully nonlinear parabolic equations in one-dimensional space

We discuss the existence of global classical solution for the uniformly parabolic equation

Galerkin method for linear parabolic equations with discontinuous solutions

Finite-element schemes are developed for solving a linear equation of parabolic type with a discontinuous solution in the space variable. Existence and uniqueness of the solution of the corresponding Cauchy problem is proved. Accuracy bounds are obtained for the finite-element scheme and the Crank-Nicholson scheme.Translated from Vychislitel'naya i Prikladnaya Matematika, No. 66, pp. 33–40, 1988.     

Interior penalty discontinuous Galerkin methods with implicit time‐integration techniques for nonlinear parabolic equations

We prove existence and numerical stability of numerical solutions of three fully discrete interior penalty discontinuous Galerkin methods for solving nonlinear parabolic equations. Under some appropriate regularity conditions, we give the l²(H¹) and l^∞(L²) error estimates of the fully discrete symmetric interior penalty discontinuous Galerkin–scheme with the implicit θ ‐schemes in time, which include backward Euler and Crank–Nicolson finite difference approximations. Our estimates are optimal with respect to the mesh size h. The theoretical results are confirmed by some numerical experiments. © 2012 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2013     

Existence of solutions for a nonlinear system of parabolic equations with gradient flow structure

We prove global existence of weak solutions of a variant of the parabolic-parabolic Keller–Segel model for chemotaxis on the whole space \({{\mathbb {R}}^d}\) for \(d\ge 3\) with a supercritical porous-medium diffusion exponent and an external drift. The structure of the equations allow the chemotactic drift to be seen both as attraction and repulsion. The method of proof relies on the inherent gradient flow structure of this system with respect to a coupled Wasserstein- \(L^2\) metric. Additional regularity estimates are derived from the dissipation of an entropy functional.