Electronic Journal of Differential Equations,
Vol. 1999(1999), No. 14, pp. 1-12.

Title: Existence of multiple solutions for quasilinear diagonal elliptic systems   

Author: Marco Squassina (Milan Univ., Italy)
         
Abstract: 
Nonsmooth-critical-point theory is applied in proving multiplicity 
results for the quasilinear symmetric elliptic system
$$
 -\sum_{i,j=1}^{n}D_j(a^{k}_{ij}(x,u)D_iu_k)+
 {1\over 2}\sum_{i,j=1}^{n}\sum_{h=1}^N
 D_{s_k}a^{h}_{ij}(x,u)D_iu_hD_ju_h=g_k(x,u)\,, 
$$ 
for $k=1,..,N$.  

Submitted January 4, 1999. Published May 10, 1999.
Math Subject Classification: 35D05, 35J20, 35J60
Key Words: Quasilinear elliptic differential systems; 
           Nonsmooth critical point theory.