Key points are not available for this paper at this time.
We study the totally nonnegative varietyG≥0G ₀in a semisimple algebraic groupGG. These varieties were introduced by G. Lusztig, and include as a special case the variety of unimodular matrices of a given order whose all minors are nonnegative. The geometric framework for our study is provided by intersectingG≥0G ₀with double Bruhat cells (intersections of cells of the two Bruhat decompositions ofGGwith respect to opposite Borel subgroups).
Fomin et al. (Fri,) studied this question.