Universality of High-Strength Tensors

Vietnam J Math. 2022;50(2):557-580. doi: 10.1007/s10013-021-00522-7. Epub 2021 Sep 28.

Abstract

A theorem due to Kazhdan and Ziegler implies that, by substituting linear forms for its variables, a homogeneous polynomial of sufficiently high strength specialises to any given polynomial of the same degree in a bounded number of variables. Using entirely different techniques, we extend this theorem to arbitrary polynomial functors. As a corollary of our work, we show that specialisation induces a quasi-order on elements in polynomial functors, and that among the elements with a dense orbit there are unique smallest and largest equivalence classes in this quasi-order.

Keywords: GL-varieties; Infinite tensors; Polynomial functor; Strength.