3 papers
math.AG2026
Permutahedra, Lusztig varieties, degenerations, and subdivisions
Allen Knutson, Mario Sanchez, Melissa Sherman-Bennett
We present an embedded (in ) degeneration of Lusztig varieties (which generalize type Hessenberg varieties) to certain unions of Richardson varieties, giving a simultaneou…
math.CO2025
Schubert puzzles and integrability I: invariant trilinear forms
Allen Knutson, Paul Zinn-Justin
The puzzle rules for computing Schubert calculus on -step flag manifolds, proven in [Knutson Tao 2003] for -step, in [Buch Kresch Purbhoo Tamvakis 2016] for -step, and con…
math.AG2024
Schubert puzzles and integrability II: multiplying motivic Segre classes
Allen Knutson, Paul Zinn-Justin
In Schubert Puzzles and Integrability I we proved several "puzzle rules" for computing products of Schubert classes in K-theory (and sometimes equivariant K-theory) of d-step flag…