[math-fun] Kontsevich periodicity conjecture

The conjecture was recently proved: http://golem.ph.utexas.edu/category/2013/10/who_ordered_that.html Start with a 3×3 matrix. Take its transpose, then take the reciprocal of each entry, then take the inverse of the whole matrix. Take the transpose of that, then take the reciprocal of each entry, then take the matrix inverse. Take the transpose of that, then take the reciprocal of each entry, and then, finally, take the matrix inverse. Theorem: Up to a bit of messing about, you’re back where you started. Does anyone know what motivated taking the element-wise inverse? I ask because it's the only nonlinear operation in AES. -- Mike Stay - metaweta@gmail.com http://www.cs.auckland.ac.nz/~mike http://reperiendi.wordpress.com