Root systems, affine subspaces, and projections
نویسندگان
چکیده
We tackle several problems related to a finite irreducible crystallographic root system $\Phi$ in the real vector space $\mathbb E$. In particular, we study combinatorial structure of subsets cut by affine subspaces E$ and their projections. As byproducts, obtain easy algebraic proofs refinements Oshima's Lemma result Kostant, partial towards resolution problem Hopkins Postnikov, new enumerative results on systems.
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ژورنال
عنوان ژورنال: Journal of Algebra
سال: 2021
ISSN: ['1090-266X', '0021-8693']
DOI: https://doi.org/10.1016/j.jalgebra.2021.07.035