Igor KlepAffiliation: University of Ljubljana, Slovenia Email: igor.klep@fmf.uni-lj.si Title Of Talk: Central simple algebras with involution and positive polynomials URL: http://arxiv.org/abs/0810.5254 Abstract: Consider a central simple algebra A with involution *. The involution is called positive if the involution trace form tr(x*x) is positive semidefinite (w.r.t. a fixed ordering of the center). A symmetric element b is defined to be positive if the scaled involution trace form tr(x*bx) is positive semidefinite giving rise to an ordering of the central simple algebra A. We discuss how these can be used to give a Positivstellensatz characterizing noncommutative real polynomials positive semidefinite on dxd matrices. This talk is partially based on joint work with T. Unger.
Last update made Mon May 18 06:30:40 EDT 2009.
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