Open AccessSums of squares in real analytic rings
Author(s) -
José F. Fernando
Publication year - 2002
Publication title -
transactions of the american mathematical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.798
H-Index - 100
eISSN - 1088-6850
pISSN - 0002-9947
DOI - 10.1090/s0002-9947-02-02956-2
Subject(s) - algorithm , annotation , computer science , type (biology) , semantics (computer science) , artificial intelligence , mathematics , biology , programming language , ecology
Let A be an analytic ring. We show:(1) A has finite Pythagoras number if and only if its real dimension is 2, and (2) if every positive semidefinite element of A is a sum of squares, then A is real and has real dimension 2