Results 71 to 80 of about 4,266 (227)

Toric amplitudes and universal adjoints

open access: yesJournal of the London Mathematical Society, Volume 113, Issue 2, February 2026.
Abstract A toric amplitude is a rational function associated with a simplicial polyhedral fan. The definition is inspired by scattering amplitudes in particle physics. We prove algebraic properties of such amplitudes and study the geometry of their zero loci. These hypersurfaces play the role of Warren's adjoint via a dual volume interpretation.
Simon Telen
wiley   +1 more source

On matroidal families [PDF]

open access: yesDiscrete Mathematics, 1979
Simoes-Pereira has defined [5,6,7] a matroidal family of graphs and has proved the existence of four matroidal families, called F"1F"2F"3and F"4 the set of polygons [@d]. Andreae [1] has shown that for every n, integer, n>=2, there is a matroidal family M"n (F"4=M"2, F"1=M"3).
openaire   +2 more sources

The Chip Firing Game and Matroid Complexes [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2001
In this paper we construct from a cographic matroid M, a pure multicomplex whose degree sequence is the h―vector of the the matroid complex of M. This result provesa conjecture of Richard Stanley [Sta96] in the particular case of cographic matroids.
Criel Merino
doaj   +1 more source

On higher Jacobians, Laplace equations, and Lefschetz properties

open access: yesBulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.
Abstract Let A$A$ be a standard graded Artinian K$\mathbb {K}$‐algebra over a field of characteristic zero. We prove that the failure of strong Lefschetz property (SLP) for A$A$ is equivalent to the osculating defect of a certain rational variety.
Charles Almeida   +2 more
wiley   +1 more source

Matroidal Structure of Rough Sets Based on Serial and Transitive Relations

open access: yesJournal of Applied Mathematics, 2012
The theory of rough sets is concerned with the lower and upper approximations of objects through a binary relation on a universe. It has been applied to machine learning, knowledge discovery, and data mining. The theory of matroids is a generalization of
Yanfang Liu, William Zhu
doaj   +1 more source

Canonical forms of oriented matroids

open access: yesBulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.
Abstract Positive geometries are semialgebraic sets equipped with a canonical differential form whose residues mirror the boundary structure of the geometry. Every full‐dimensional projective polytope is a positive geometry. Motivated by the canonical forms of polytopes, we construct a canonical form for any tope of an oriented matroid inside the Orlik–
Christopher Eur, Thomas Lam
wiley   +1 more source

Quasiregular Matroids

open access: yesThe Electronic Journal of Combinatorics, 2018
Regular matroids are binary matroids with no minors isomorphic to the Fano matroid $F_7$ or its dual $F_7^*$. Seymour proved that 3-connected regular matroids are either graphs, cographs, or $R_{10}$, or else can be decomposed along a non-minimal exact 3-separation induced by $R_{12}$.
openaire   +2 more sources

Some inequalities for the Tutte polynomial

open access: yes, 2011
This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2011 ElsevierWe prove that the Tutte polynomial of a coloopless paving matroid is convex along the portion of the line x+y=p ...
Noble, Steven D.   +15 more
core   +1 more source

Hall's marriage theorem

open access: yesJournal of the London Mathematical Society, Volume 113, Issue 1, January 2026.
Abstract In 1935, Philip Hall published what is often referred to as ‘Hall's marriage theorem’ in a short paper (P. Hall, J. Lond. Math. Soc. (1) 10 (1935), no. 1, 26–30.) This paper has been very influential. I state the theorem and outline Hall's proof, together with some equivalent (or stronger) earlier results, and proceed to discuss some the many ...
Peter J. Cameron
wiley   +1 more source

Modular elimination in matroids and oriented matroids

open access: yesEuropean Journal of Combinatorics, 2011
We introduce a new axiomatization of matroid theory that requires the elimination property only among modular pairs of circuits, and we present a cryptomorphic phrasing thereof in terms of Crapo's axioms for flats. This new point of view leads to a corresponding strengthening of the circuit axioms for oriented matroids.
openaire   +2 more sources

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