## Differential and Integral Equations

- Differential Integral Equations
- Volume 13, Number 10-12 (2000), 1233-1262.

### Existence, uniqueness, and longtime behavior for a nonlinear Volterra integrodifferential equation

Viorel Barbu, Pierluigi Colli, Gianni Gilardi, and Maurizio Grasselli

#### Abstract

We consider an initial and boundary value problem for a nonlinear Volterra integrodifferential equation. This equation governs the evolution of a pair of state variables, $u$ and $\vartheta$, which are mutually related by a maximal monotone graph $\gamma$ in ${{\Bbb R}}\times{{\Bbb R}}.$ The model can be viewed, for instance, as a generalized Stefan problem within the theory of heat conduction in materials with memory. Besides, it can be used for describing some diffusion processes in fractured media. The relation defined by $\gamma$ is properly interpreted and generalized in terms of a subdifferential operator associated with $\gamma$ and acting from $H^1(\Omega)$ to its dual space. Then, the generalized problem is formulated as an abstract Cauchy problem for a perturbation of a nonlinear semigroup, and existence and uniqueness of a solution $(u,\vartheta)$ can be proved via a fixed-point argument whatever the maximal monotone graph $\gamma$ is. Moreover, the meaning of $\gamma$ as a pointwise relationship is recovered almost everywhere, in the case when $\gamma$ is bounded on bounded subsets of ${{\Bbb R}}$. Finally, under some other restrictions on $\gamma$, the longtime behavior of the solution is investigated, in a more specific context related to the generalized Stefan problem.

#### Article information

**Source**

Differential Integral Equations, Volume 13, Number 10-12 (2000), 1233-1262.

**Dates**

First available in Project Euclid: 21 December 2012

**Permanent link to this document**

https://projecteuclid.org/euclid.die/1356061125

**Mathematical Reviews number (MathSciNet)**

MR1785706

**Zentralblatt MATH identifier**

0981.45006

**Subjects**

Primary: 45K05: Integro-partial differential equations [See also 34K30, 35R09, 35R10, 47G20]

Secondary: 45N05: Abstract integral equations, integral equations in abstract spaces

#### Citation

Barbu, Viorel; Colli, Pierluigi; Gilardi, Gianni; Grasselli, Maurizio. Existence, uniqueness, and longtime behavior for a nonlinear Volterra integrodifferential equation. Differential Integral Equations 13 (2000), no. 10-12, 1233--1262. https://projecteuclid.org/euclid.die/1356061125