Sums of squares in -integers
arXiv:2005.06566
Abstract
In totally real number fields, we characterize the rings of -integers (obtained by inverting a rational integer ) such that all their totally positive elements are represented as a sum of squares. We further obtain partial answers to the question: when are all the totally positive algebraic integers that are divisible by represented as a sum of squares?
6 pages, to appear in New York J. Math