Supersolvable Frame-matroid and Graphic-lift Lattices
نویسندگان
چکیده
منابع مشابه
Supersolvable Frame-matroid and Graphic-lift Lattices
A geometric lattice is a frame if its matroid, possibly after enlargement, has a basis such that every atom lies under a join of at most two basis elements. Examples include all subsets of a classical root system. Using the fact that nitary frame matroids are the bias matroids of biased graphs, we characterize modular coatoms in frames of nite rank and we describe explicitly the frames that are...
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Finite point configurations in projective spaces are combinatorially described by matroids, where full (finite) projective spaces correspond to connected modular matroids. Every representable matroid can in fact be extended to a modular one. However, we show that some matroids do not even have a modularly complemented extension. Enlarging the class of “ambient spaces” under consideration, we sh...
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Stanley [18] introduced the notion of a supersolvable lattice, L, in part to combinatorially explain the factorization of its characteristic polynomial over the integers when L is also semimodular. He did this by showing that the roots of the polynomial count certain sets of atoms of the lattice. In the present work we define an object called an atom decision tree. The class of semimodular latt...
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Let G be a finite simple graph. From the pioneering work of R. P. Stanley it is known that the cycle matroid of G is supersolvable if and only if G is chordal. The chordal binary matroids are not in general supersolvable. Nevertheless we prove that every supersolvable binary matroid determines canonically a chordal graph.
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ژورنال
عنوان ژورنال: European Journal of Combinatorics
سال: 2001
ISSN: 0195-6698
DOI: 10.1006/eujc.2000.0418