Pure Math Grad Student Seminar (PuMaGraSS)

Speaker: Sveta Makarova

Title: Understanding 2x2 Matrix Multiplicaiton

Abstract: To start, I will formulate a classical fact that one can multiply two 2x2 matrices using just 7 multiplications instead of the expected 8. Then I will explain why this means that a certain cubic tensor lies on the variety of secant 6-spaces to a Segre variety. This geometric problem turns out to be unexpectedly interesting, and to demonstrate the nontriviality, I will switch to discussing a simpler case of 2x2x2 tensors.