3 papers
math.CO2020
Tropical flag varieties
Madeline Brandt, Christopher Eur, Leon Zhang
Flag matroids are combinatorial abstractions of flags of linear subspaces, just as matroids are of linear subspaces. We introduce the flag Dressian as a tropical analogue of the pa…
math.CO2018
Computing Convex Hulls in the Affine Building of SL_d
Leon Zhang
We describe an algorithm for computing the convex hull of a finite collection of points in the affine building of SL_d(K), for K a field with discrete valuation. These convex hulls…
math.AG2018
Computing Unit Groups of Curves
Justin Chen, Sameera Vemulapalli, Leon Zhang
The group of units modulo constants of an affine variety over an algebraically closed field is free abelian of finite rank. Computing this group is difficult but of fundamental imp…