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Related papers: Twist polynomials of delta-matroids

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In [27], we provided results on the $p$-modulus of the family of all bases of matroids and showed that it recovers various concepts in matroid theory, including strength, fractional arboricity, and principal partitions. In particular, the…

Combinatorics · Mathematics 2026-04-15 Huy Truong , Pietro Poggi-Corradini

In 1977, Yu. V. Matiyasevich proposed a formula expressing the chromatic polynomial of an arbitrary graph as a linear combination of flow polynomials of subgraphs of the original graph. In this paper, we prove that this representation is a…

Combinatorics · Mathematics 2024-06-17 E. Yu. Lerner

We consider symmetric partial exclusion and inclusion processes in a general graph in contact with reservoirs, where we allow both for edge disorder and well-chosen site disorder. We extend the classical dualities to this context and then…

Probability · Mathematics 2023-12-04 Simone Floreani , Frank Redig , Federico Sau

In this paper, we analyze the Bollob\'as and Riordan polynomial $\mathcal{R}$ for ribbon graphs with half-ribbons introduced in [Combinatorics, Probability and Computing 31, 507-549, 2022]. We prove the universality property of a…

Geometric Topology · Mathematics 2023-01-09 Remi C. Avohou , Joseph Ben Geloun , Mahouton N. Hounkonnou

We call a Delta Diagram any diagram of a knot or link whose regions (including the unbounded one) have 3, 4, or 5 sides. We prove that any knot or link admits a delta diagram. We define and estimate combinatorial link invariants stemming…

Geometric Topology · Mathematics 2016-01-26 Slavik Jablan , Louis H. Kauffman , Pedro Lopes

Hilbert polynomials have positivity properties under favorable conditions. We establish a similar "K-theoretic positivity" for matroids. As an application, for a multiplicity-free subvariety of a product of projective spaces such that the…

Algebraic Geometry · Mathematics 2024-09-20 Christopher Eur , Matt Larson

This is a continuation of the series of notes on the dynamics of quadratic polynomials. We show the following Rigidity Theorem: Any combinatorial class contains at most one quadratic polynomial satisfying the secondary limbs condition with…

Dynamical Systems · Mathematics 2016-09-06 Mikhail Lyubich

In this article we give a characterization of left (right) quasi-duo differential polynomial rings. In particular, we show that a differential polynomial ring is left quasi-duo if and only if it is right quasi-duo. This yields a partial…

Rings and Algebras · Mathematics 2017-01-03 Mai Hoang Bien , Johan Öinert

We give new characterizations for the class of uniformly dense matroids and study applications of these characterizations to graphic and real representable matroids. We show that a matroid is uniformly dense if and only if its base polytope…

Combinatorics · Mathematics 2026-02-03 Karel Devriendt , Raffaella Mulas

By finding orthogonal representation for a family of simple connected called $\delta$-graphs it is possible to show that $\delta$-graphs satisfy delta conjecture. An extension of the argument to graphs of the form…

Combinatorics · Mathematics 2018-06-20 Pedro Díaz Navarro

Chordal graphs are important in the structural and algorithmic graph theory. A digraph analogue of chordal graphs was introduced by Haskin and Rose in 1973 but has not been a subject of active studies until recently when a characterization…

Combinatorics · Mathematics 2021-03-03 Jing Huang , Ying Ying Ye

In their study of a binomial sum related to Wolstenholme's theorem, Chamberland and Dilcher prove that the corresponding sequence modulo primes $p$ satisfies congruences that are analogous to Lucas' theorem for the binomial coefficients…

Number Theory · Mathematics 2025-11-04 Armin Straub

In "A survey on the Turaev genus of knots," Champanerkar and Kofman propose several open questions. The first asks whether the polynomial whose coefficients count the number of quasi-trees of the all-A ribbon graph obtained from a diagram…

Geometric Topology · Mathematics 2016-02-23 Cody Armond , Moshe Cohen

Raghunathan at al. [9] introduced splitting operation with respect to a pair of element for binary matroid and characterized Eulerian binary matroids using it. In general, the splitting operation does not preserve the graphicness property…

Combinatorics · Mathematics 2020-02-13 Ganesh Mundhe , K. V. Dalvi

The Tutte polynomial is the most general invariant of matroids and graphs that can be computed recursively by deleting and contracting edges. We generalize this invariant to any class of combinatorial objects with deletion and contraction…

Combinatorics · Mathematics 2019-02-04 Clément Dupont , Alex Fink , Luca Moci

We introduce a new matroid (graph) invariant, the arboricity polynomial. Given a matroid, the arboricity polynomial enumerates the number of covers of the ground set by disjoint independent sets. We establish the polynomiality of the…

Combinatorics · Mathematics 2025-05-09 Felix Breuer , Caroline J Klivans

We reduce a strong version of the twist conjecture for Artin groups to Artin groups whose defining graphs have no separating vertices. This produces new examples of Artin groups satisfying the conjecture, and sheds more light on the…

Group Theory · Mathematics 2026-05-13 Oli Jones , Giorgio Mangioni , Giovanni Sartori

Finite order invariants (Vassiliev invariants) of knots are expressed in terms of weight systems, that is, functions on chord diagrams satisfying the four-term relations. Weight systems have graph analogues, so-called $4$-invariants of…

Combinatorics · Mathematics 2018-06-01 V. I. Zhukov

Following Britz, Johnsen, Mayhew and Shiromoto, we consider demi\-ma\-troids as a(nother) natural generalization of matroids. As they have shown, demi\-ma\-troids are the appropriate combinatorial objects for studying Wei's duality. Our…

Combinatorics · Mathematics 2019-07-24 Jose Martinez-Bernal , Miguel A. Valencia-Bucio , Rafael H. Villarreal

The present paper investigates a natural generalization of the duality between Riemannian symmetric pairs of compact type and those of non-compact type \`a la \'E. Cartan. The main result of this paper is to construct an explicit…

Representation Theory · Mathematics 2021-03-26 Kurando Baba , Osamu Ikawa , Atsumu Sasaki