Factorizations of $k$-nonnegative matrices
نویسندگان
چکیده
A matrix is $k$-nonnegative if all its minors of size $k$ or less are nonnegative. We give a parametrized set generators and relations for the semigroup $n\times n$ invertible matrices in two special cases: when $k = n-1$ n-2$, restricted to unitriangular matrices. For these cases, we prove that can be partitioned into cells based on their factorizations generators, generalizing notion Bruhat from totally nonnegative Like cells, homeomorphic open balls have topological structure neatly relates closure subwords factorizations. In case $(n-2)$-nonnegative matrices, show form Bruhat-like CW-complex.
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ژورنال
عنوان ژورنال: The Journal of Combinatorics
سال: 2022
ISSN: ['2150-959X', '2156-3527']
DOI: https://doi.org/10.4310/joc.2022.v13.n2.a2