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This is a continuation of the early paper concerning matroid base polytope decomposition. Here, we will present sufficient conditions on $M$ so its base matroid polytope $P(M)$ has a {\em sequence} of hyperplane splits. The latter yields to…

Combinatorics · Mathematics 2013-11-28 Vanessa Chatelain , Jorge Ramirez Alfonsin

We provide a formula for the Ehrhart polynomial of the connected matroid of size $n$ and rank $k$ with the least number of bases, also known as a minimal matroid. We prove that their polytopes are Ehrhart positive and $h^*$-real-rooted (and…

Combinatorics · Mathematics 2021-06-17 Luis Ferroni

A simple binary matroid is called claw-free if none of its rank-3 flats are independent sets. These objects can be equivalently defined as the sets $E$ of points in $\mathrm{PG}(n-1,2)$ for which $|E \cap P|$ is not a basis of $P$ for any…

Combinatorics · Mathematics 2018-08-01 Peter Nelson , Kazuhiro Nomoto

Given a matroid or flag of matroids we introduce several broad classes of polynomials satisfying Deletion-Contraction identities, and study their singularities. There are three main families of polynomials captured by our approach:…

Algebraic Geometry · Mathematics 2024-04-12 Daniel Bath , Uli Walther

We study varieties associated to hypergraphs from the point of view of projective geometry and matroid theory. We describe their decompositions into matroid varieties, which may be reducible and can have arbitrary singularities by the…

Combinatorics · Mathematics 2025-12-18 Oliver Clarke , Kevin Grace , Fatemeh Mohammadi , Harshit J Motwani

A matroid is a notion of independence in combinatorial optimization which is closely related to computational efficiency. In particular, it is well known that the maximum of a constrained modular function can be found greedily if and only…

Machine Learning · Computer Science 2015-04-15 Branislav Kveton , Zheng Wen , Azin Ashkan , Hoda Eydgahi , Brian Eriksson

A matroid is a machine capturing linearity of mathematical objects and producing combinatorial structures. Matroid structure arises everywhere since linearity is a ubiquitous concept. One natural way to obtain matroids is by considering…

Combinatorics · Mathematics 2023-03-14 Jaeho Shin

Introduced by Ardila (J. Combin. Theory Ser. A, 2003), the Catalan matroid is obtained by defining the bases of the matroid using Dyck paths from $(0,0)$ to $(n,n)$. Further research has gone into the topic, with variants like lattice path…

Combinatorics · Mathematics 2022-09-27 Hiranya Kishore Dey , Brahadeesh Sankarnarayanan , S. Venkitesh

The class of 2-regular matroids is a natural generalisation of regular and near-regular matroids. We prove an excluded-minor characterisation for the class of 2-regular matroids. The class of 3-regular matroids coincides with the class of…

Combinatorics · Mathematics 2023-09-07 Nick Brettell , James Oxley , Charles Semple , Geoff Whittle

Let $M$ be a 3-connected matroid, and let $N$ be a 3-connected minor of $M$. We say that a pair $\{x_1,x_2\} \subseteq E(M)$ is $N$-detachable if one of the matroids $M/x_1/x_2$ or $M \backslash x_1 \backslash x_2$ is both 3-connected and…

Combinatorics · Mathematics 2020-02-25 Nick Brettell , Geoff Whittle , Alan Williams

We develop a strong connection between maximally commuting bases of orthogonal unitary matrices and mutually unbiased bases. A necessary condition of the existence of mutually unbiased bases for any finite dimension is obtained. Then a…

Quantum Physics · Physics 2007-05-23 Somshubhro Bandyopadhyay , P. Oscar Boykin , Vwani Roychowdhury , Farrokh Vatan

We introduce dual matroids of 2-dimensional simplicial complexes. Under certain necessary conditions, duals matroids are used to characterise embeddability in 3-space in a way analogous to Whitney's planarity criterion. We further use dual…

Combinatorics · Mathematics 2017-09-15 Johannes Carmesin

In this paper, we investigate three problems concerning the toric ideal associated to a matroid. Firstly, we list all matroids $\mathcal M$ such that its corresponding toric ideal $I_{\mathcal M}$ is a complete intersection. Secondly, we…

Commutative Algebra · Mathematics 2017-01-17 Ignacio García-Marco , Jorge Luis Ramírez Alfonsín

In 1980, White conjectured that the toric ideal of a matroid is generated by quadratic binomials corresponding to a symmetric exchange. In this paper, we compute Gr\"obner bases of toric ideals associated with matroids and show that, for…

Commutative Algebra · Mathematics 2020-04-28 Ken-ichi Hayase , Takayuki Hibi , Koyo Katsuno , Kazuki Shibata

The famous Braess paradox describes the following phenomenon: It might happen that the improvement of resources, like building a new street within a congested network, may in fact lead to larger costs for the players in an equilibrium. In…

Computer Science and Game Theory · Computer Science 2017-01-11 Satoru Fujishige , Michel X. Goemans , Tobias Harks , Britta Peis , Rico Zenklusen

The family of 2-level matroids, that is, matroids whose base polytope is 2-level, has been recently studied and characterized by means of combinatorial properties. 2-level matroids generalize series-parallel graphs, which have been already…

Combinatorics · Mathematics 2015-10-15 Francesco Grande , Juanjo Rué

In this paper, we define generalized splitting and element splitting operations on $p$-matroids. $p$-matroids are the matroids representable over $GF(p).$ The circuits and the bases of the new matroid are characterized in terms of circuits…

Combinatorics · Mathematics 2023-03-06 Sachin Gunjal , Uday Jagadale , Prashant Malavadkar

We introduce the families of solvable and nilpotent matroids, examining their realization spaces, closures, and associated matroid and circuit varieties. We study their realizability, as well as the irreducible decomposition of their…

Combinatorics · Mathematics 2025-10-29 Emiliano Liwski , Fatemeh Mohammadi

An old problem of Moser asks: how large of a union-free subfamily does every family of m sets have? A family of sets is called union-free if there are no three distinct sets in the family such that the union of two of the sets is equal to…

Combinatorics · Mathematics 2011-03-17 Jacob Fox , Choongbum Lee , Benny Sudakov

For any minor-closed class of matroids over a fixed finite field, we state an exact structural characterization for the sufficiently connected matroids in the class. We also state a number of conjectures that might be approachable using the…

Combinatorics · Mathematics 2015-01-06 Jim Geelen , Bert Gerards , Geoff Whittle