Hermitian sums of squares

Mihail Putinar (Univ. de California de Santa Barbara, EEUU; Univ. de Newcastle, Reino Unido)
Jueves, 23 de junio, 12:00h. Dpto. Matemáticas UAM, Módulo 17, Aula 520
Abstract: As old and ubiquitous positive definite Hermitian forms may be, they still provide surprises and unexpected ramifications to other fields. A theorem of Quillen about positive definite forms on an odd dimensional sphere will be the starting point of our lecture, leading to a novel classification of real algebraic varieties and a precise Positivstellensatz in the Hermitian context.
Applications to the construction of tight wavelet frames and to global, non-convex optimization will be presented.