ACTA issues

## Extensions of operator valued positive definite functions on an interval of \${\msbm Z}^2\$ with the lexicographic order

Ramón Bruzual, Marisela Domínguez

Acta Sci. Math. (Szeged) 66:3-4(2000), 623-631
2756/2009

 Abstract. We prove that an operator valued positive definite function defined on an interval of \${\msbm Z}^2\$ with the lexicographic order can be extended to a positive definite function on the whole discrete plane. AMS Subject Classification (1991): 43A35, 47D03 Keyword(s): operator valued positive definite functions, semigroup of operators, lexicographic order Received April 29, 1999, and in revised form November 8, 1999. (Registered under 2756/2009.)