## Advances in Differential Equations

- Adv. Differential Equations
- Volume 16, Number 3/4 (2011), 221-256.

### Singular behavior of the solution of the periodic Dirichlet heat equation in weighted $L^p$-Sobolev spaces

Colette De Coster and Serge Nicaise

#### Abstract

We consider the heat equation in a polygonal domain $\Omega$ of the plane in weighted $L^p$-Sobolev spaces \begin{equation} \begin{array}{cl} \partial_t u -\Delta u = h, & \mbox{in } \Omega \times {(-\pi,\pi ) }, \\ u=0,& \mbox{on } \partial\Omega \times {[-\pi,\pi]}, \\ u(\cdot, -\pi)=u(\cdot, \pi),& \mbox{in } \Omega. \end{array} \tag*{(0.1)} \end{equation} Here $h$ belongs to $L^p(-\pi,\pi;L^p_\mu(\Omega))$, where $L^p_\mu(\Omega)=\{v \in L^p_{loc}(\Omega): r^\mu v\in L^p(\Omega)\},$ with a real parameter $\mu$ and $r(x)$ the distance from $x$ to the set of corners of $\Omega$. We give sufficient conditions on $\mu$, $p$, and $\Omega$ that guarantee that problem (0.1) has a unique solution $u\in L^p(-\pi,\pi;L^p_\mu(\Omega))$ that admits a decomposition into a regular part in weighted $L^p$-Sobolev spaces and an explicit singular part. The classical Fourier transform techniques do not allow one to handle such a general case. Hence we use the theory of sums of operators.

#### Article information

**Source**

Adv. Differential Equations, Volume 16, Number 3/4 (2011), 221-256.

**Dates**

First available in Project Euclid: 18 December 2012

**Permanent link to this document**

https://projecteuclid.org/euclid.ade/1355854308

**Mathematical Reviews number (MathSciNet)**

MR2767078

**Zentralblatt MATH identifier**

1227.35016

**Subjects**

Primary: 35K15: Initial value problems for second-order parabolic equations 35B65: Smoothness and regularity of solutions

#### Citation

De Coster, Colette; Nicaise, Serge. Singular behavior of the solution of the periodic Dirichlet heat equation in weighted $L^p$-Sobolev spaces. Adv. Differential Equations 16 (2011), no. 3/4, 221--256. https://projecteuclid.org/euclid.ade/1355854308