The closure of a linear space in a product of lines

Autor: Federico Ardila, Adam Boocher
Rok vydání: 2015
Předmět:
Zdroj: Journal of Algebraic Combinatorics. 43:199-235
ISSN: 1572-9192
0925-9899
DOI: 10.1007/s10801-015-0634-x
Popis: Given a linear space L in affine space A^n, we study its closure L' in the product of projective lines (P^1)^n. We show that the degree, multigraded Betti numbers, defining equations, and universal Grobner basis of its defining ideal I(L') are all combinatorially determined by the matroid M of L. We also prove I(L') and all of its initial ideals are Cohen-Macaulay with the same Betti numbers. In so doing, we prove that the initial ideals of I(L') are the Stanley-Reisner ideals of an interesting family of simplicial complexes related to the basis activities of M. We also describe the state polytope of I(L'), which is related to the matroid basis polytope of M.
Comment: 33 pages, 5 figures
Databáze: OpenAIRE