Departmental Colloquium
Bernd Sturmfels
UC Berkeley
How to subdivide the 4-cube
Abstract: The hyperdeterminant of format 2 x 2 x 2 x 2 is a polynomial of degree 24
in 16 unknowns which has 2894276 terms. We compute the Newton polytope of
this polynomial and the secondary polytope of the 4-cube. The 87959448
regular triangulations of the 4-cube are classified into 25448
D-equivalence classes, one for each vertex of the Newton polytope. The
4-cube has 80876 coarsest regular subdivisions, one for each facet of the
secondary polytope, but only 268 of them come from the hyperdeterminant.
Joint work with Debbie Grier, Peter Huggins and Josephine Yu
(math.CO/0602149)
Friday April 7, 2006 at 2:00 PM in SEO 636