RT Journal Article
T1 On Hilbert's 17th Problem for global analytic functions indimension 3.
A1 Fernando Galván, José Francisco
AB Among the invariant factors g of a positive semidefinite analytic function f on R-3, those g whose zero set Y is a curve are called special. We show that if each special g is a sum of squares of global meromorphic functions on a neighbourhood of Y, then f is a sum of squares of global meromorphic functions. Here sums can be (convergent) infinite, but we also find some sufficient conditions to get finite sums of squares. In addition, we construct several examples of positive semidefinite analytic functions which are infinite sums of squares but maybe could not be finite sums of squares.
PB European Mathematical Society
SN 0010-2571
YR 2008
FD 2008
LK https://hdl.handle.net/20.500.14352/49897
UL https://hdl.handle.net/20.500.14352/49897
LA eng
NO GAAR
NO GAAR
DS Docta Complutense
RD 4 abr 2025