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Related papers: A note on the structure of expanders

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We prove a general duality theorem for tangle-like dense objects in combinatorial structures such as graphs and matroids. This paper continues, and assumes familiarity with, the theory developed in [6]

Combinatorics · Mathematics 2014-06-17 Reinhard Diestel , Sang-il Oum

This thesis develops the theory of bundle gerbes and examines a number of useful constructions in this theory. These allow us to gain a greater insight into the structure of bundle gerbes and related objects. Furthermore they naturally lead…

Differential Geometry · Mathematics 2007-05-23 Stuart Johnson

A "folklore conjecture, probably due to Tutte" (as described in [P.D. Seymour, Sums of circuits, Graph theory and related topics (Proc. Conf., Univ. Waterloo, 1977), pp. 341-355, Academic Press, 1979]) asserts that every bridgeless cubic…

Combinatorics · Mathematics 2011-01-14 Bojan Mohar

Using the theory of extensors developed in a previous paper we present a theory of the parallelism structure on arbitrary smooth manifold. Two kinds of Cartan connection operators are introduced and both appear in intrinsic versions (i.e.,…

Mathematical Physics · Physics 2007-05-23 V. V. Fernandez , A. M. Moya , E. Notte-Cuello , W. A. Rodrigues

We introduce and study analogues of expander and hyperfinite graph sequences in the context of directed acyclic graphs, which we call "extender" and "hypershallow" graph sequences, respectively. Our main result is a probabilistic…

Combinatorics · Mathematics 2023-06-22 Endre Csóka , Łukasz Grabowski

A broader definition of generalized truncations of graphs is introduced followed by an exploration of some standard concepts and parameters with regard to generalized truncations.

Combinatorics · Mathematics 2020-07-10 Brian Alspach , Joshua B. Connor

We produce a new, shorter construction of a minor-universal planar graph.

Combinatorics · Mathematics 2023-09-14 George Kontogeorgiou

We tackle the problem of constructing increasing-chord graphs spanning point sets. We prove that, for every point set P with n points, there exists an increasing-chord planar graph with O(n) Steiner points spanning P. Further, we prove…

Computational Geometry · Computer Science 2014-08-13 Hooman Reisi Dehkordi , Fabrizio Frati , Joachim Gudmundsson

In this paper the problem of the existence of regular nut graphs is addressed. A generalization of Fowler's Construction which is a local enlargement applied to a vertex in a graph is introduced to generate nut graphs of higher order. Let…

Combinatorics · Mathematics 2019-11-13 John Baptist Gauci , Tomaz Pisanski , Irene Sciriha

A result on the structure of expansive matrices in an indefinite inner product space is derived, which exhibits the largest unitary compression of the matrix.

Functional Analysis · Mathematics 2022-05-24 A. C. M. Ran

In this note, we give a remark on the structure of centralizers of involutions in Coxeter groups.

Group Theory · Mathematics 2023-01-02 Koji Nuida

This is a new and short proof of the main theorem of classical structure tree theory. Namely, we show the existence of certain automorphism-invariant tree-decompositions of graphs based on the principle of removing finitely many edges. This…

Group Theory · Mathematics 2010-03-05 Bernhard Krön

The main purpose of this note is to pose a couple of problems which are easily formulated thought some seem to be not yet solved. These problems are of general interest for discrete mathematics including a new twig of a bough of theory of…

Combinatorics · Mathematics 2010-11-16 A. K. Kwasniewski

This note is on the structures of line graphs and 2-variegated graphs. We have given here solutions of some graph equations involving line graphs and 2-variegated graphs.

Combinatorics · Mathematics 2025-08-08 Ranjan N. Naik

A general theorem on fibers of singular sets is presented.

Complex Variables · Mathematics 2013-11-01 Małgorzata Zajęcka

A 2-factor of a graph $G$ is a 2-regular spanning subgraph of $G$. We present a survey summarising results on the structure of 2-factors in regular graphs, as achieved by various researchers in recent years.

Combinatorics · Mathematics 2024-08-16 D. Labbate , F. Romaniello

In this note, we give an alternative construction of the $G_2(2)$-graph from a $U_3(2)$-geometry.

Combinatorics · Mathematics 2026-01-21 Koichi Inoue

We investigate graphs that have characteristic-dependent well-covered dimension and show how more of these graphs can be constructed from known ones.

Combinatorics · Mathematics 2015-06-02 Joseph Burdick , Oscar Vega

Article explicitly expresses Subgraph Isomorphism by a polynomial size asymmetric linear system.

Discrete Mathematics · Computer Science 2008-11-10 Sergey Gubin

We present an explicit connected spanning structure that appears in a random graph just above the connectivity threshold with high probability.

Combinatorics · Mathematics 2021-11-29 Yahav Alon , Michael Krivelevich , Peleg Michaeli