Bulletin of the Korean Mathematical Society ( Vol.43 NO.4 / 2006 ) Title Multiplicity results for a class of second order superlinear difference systems(ENG) Author Guoqing Zhang ,Sanyang Liu  MSC 34B16, 39A10 Publication Page 693-701 Page Abstract 1. Introduction 2. Preliminaries 3. Proof of Theorem 1.1 Own Status Keyword difference systems, multiple, critical point theory, super-linear Note Summary Using Minimax principle and Linking theorem in critical point theory, we prove the existence of two nontrivial solutions for the following second order superlinear difference systems [ (P)left { egin{array}{ll} Delta^{2}x(k-1)+g(k,y(k))=0,&{kin [1,T],}\ Delta^{2}y(k-1)+f(k,x(k))=0,&{kin [1,T],}\ x(0)=y(0)=0,x(T+1)=y(T+1)=0, end{array} ight. ] where $T$ is a positive integer, [1,T] is the discrete interval ${1,2,ldots,$ $T}, Delta x(k)=x(k+1)-x(k)$ is the forward difference operator and $ riangle^{2}x(k)= riangle( riangle x(k))$. Attach [DVI]  [PDF]