Reflections and powers of multisorted minions

Autor: Erkko Lehtonen, Reinhard Pöschel

Publikováno v: Repositório Científico de Acesso Aberto de Portugal
Repositório Científico de Acesso Aberto de Portugal (RCAAP)
instacron:RCAAP

Classes of multisorted minions closed under extensions, reflections, and direct powers are considered from a relational point of view. As a generalization of a result of Barto, Opr\v{s}al, and Pinsker, the closure of a multisorted minion is character

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When excluding one matroid prevents infinite antichains

Autor: James Oxley, Natalie Hine

Publikováno v: Advances in Applied Mathematics. 45(1):74-76

Geelen, Gerards, and Whittle have announced that there are no infinite sets of binary matroids none of which is isomorphic to a minor of another. In this paper, we use this result to determine precisely when a minor-closed class of matroids with a si

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On the growth rate of minor-closed classes of graphs

Autor: Bernardi, Olivier, Noy, Marc, Welsh, Dominic

Publikováno v: Recercat. Dipósit de la Recerca de Catalunya
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The related article "Growth constants of minor-closed classes of graphs" (containing more results) is published in J. Combin. Theory, Ser B. Vol 100 (2010); A minor-closed class of graphs is a set of labelled graphs which is closed under isomorphism

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d3c1495d7ee31c8395dec706349072ca
http://hdl.handle.net/2072/12526

Colorings and Homomorphisms of Minor Closed Classes

Autor: Jaroslav Nešetřil, Patrice Ossona de Mendez

Publikováno v: Algorithms and Combinatorics ISBN: 9783642624421
Discrete and Computational Geometry
Discrete and Computational Geometry, Springer Verlag, 2003, The Goodman-Pollack Festschrift, volume 25 of Algorithms and Combinatorics, pp.651-664

We relate acyclic (and star) chromatic number of a graph to the chromatic number of its minors and as a consequence we show that the set of all triangle free planar graphs is homomorphism bounded by a triangle free graph. This solves a problem posed

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https://doi.org/10.1007/978-3-642-55566-4_29