What is...the Complexity of Matrix Multiplication?
This page hosts information on Pierre Lairez' talk "What is … the
Complexity of Matrix Multiplication?" at the
"What is …?" seminar. The talk will take place on Friday, April 24, 1:00pm at the BMS Loft at
Urania. This talk will help you better understand the talk by
Peter Bürgisser, which will start at 2pm.
Abstract
Studies in computer algebra led to numerous efficient algorithms to solve
many kinds of difficult problems (e.g., large integer multiplication).
Complexity theory focuses on problems for which an efficient solution is not
known and tries to grasp the intrinsic difficulty of problems. This involves
both searching for lower bounds and upper bounds.
Matrix multiplication is one of these hard problems. The obvious algorithm
needs n^3 scalar multiplications to multiply two n by n matrices, and it is
far from optimal. Simple methods and sophisticated tools allow to lower this
bound, but it seems likely that we are still not close to optimal.