3 papers
math.CO2016
Two double poset polytopes
Thomas Chappell, Tobias Friedl, Raman Sanyal
To every poset P, Stanley (1986) associated two polytopes, the order polytope and the chain polytope, whose geometric properties reflect the combinatorial qualities of P. This cons…
math.AG2016
Reflection groups, reflection arrangements, and invariant real varieties
Tobias Friedl, Cordian Riener, Raman Sanyal
Let be a nonempty real variety that is invariant under the action of a reflection group . We conjecture that if is defined in terms of the first basic invariants of…
math.AG2015
Divisors on Projective Hibi Varieties
Tobias Friedl
We compute the divisor class group and the Picard group of projective varieties with Hibi rings as homogeneous coordinate rings. These varieties are precisely the toric varieties a…