Electronic Journal of Differential Equations,
Vol. 2006(2006), No. 118, pp. 1-20.

Title: Dirichlet forms for general Wentzell boundary conditions,
       analytic semigroups, and cosine operator functions

Authors: Delio Mugnolo    (Univ. degli Studi di Bari, Italy)
         Silvia Romanelli (Univ. degli Studi di Bari, Italy)
	 
Abstract: 
 The aim of this paper is to study uniformly elliptic operators
 with general Wentzell boundary conditions in suitable $L^p$-spaces
 by using the approach of sesquilinear forms.
 We use different tools to re-prove analiticity and related results
 concerning the semigroups generated by the above operators.
 In addition, we make some complementary observations on, among
 other things, compactness issues and characterization of domains. 

Submitted June 8, 2006. Published September 28, 2006.
Math Subject Classifications: 47D06, 35J20, 35J25.
Key Words: General Wentzell boundary conditions; Dirichlet forms;
          Ultracontractive semigroups; Cosine operator functions.