Ehemalige Mitarbeiter

Prof. Dr. Martin Lotz

Kontakt
Mathematics Institute
Zeeman Building
University of Warwick
Coventry CV4 7AL
United Kingdom

Persönliche Homepage
http://homepages.warwick.ac.uk/staff/Martin.Lotz/

Lower Bounds on the Bounded Coefficient Complexity of Bilinear Maps
Zitatschlüssel	BL-Lower-Bounds-On-The-Bounded-Coefficient-Complexity-Of-Bilinear-Maps-1
Autor	Peter Bürgisser and Martin Lotz
Buchtitel	In Proceedings of 43rd FOCS
Seiten	658-668
Jahr	2002
Adresse	Vancouver
Monat	November 16-19
Zusammenfassung	We prove lower bounds of order nłog n for both the problem of multiplying polynomials of degree n, and of dividing polynomials with remainder, in the model of bounded coefficient arithmetic circuits over the complex numbers. These lower bounds are optimal up to order of magnitude. The proof uses a recent idea of R. Raz [Proc.\ 34th STOC 2002] proposed for matrix multiplication. It reduces the linear problem of multiplying a random circulant matrix with a vector to the bilinear problem of cyclic convolution. We treat the arising linear problem by extending J. Morgenstern's bound [J.\ ACM 20, pp.\ 305-306, 1973] in a unitarily invariant way. This establishes a new lower bound on the bounded coefficient complexity of linear forms in terms of the singular values of the corresponding matrix. In addition, we extend these lower bounds for linear and bilinear maps to a model of circuits that allows a restricted number of unbounded scalar multiplications.