English
Related papers

Related papers: Gonality of Expander Graphs

200 papers

We find an upper bound for the asymptotic dimension of a hyperbolic metric space with a set of geodesics satisfying a certain boundedness condition studied by Bowditch. The primary example is a collection of tight geodesics on the curve…

Geometric Topology · Mathematics 2014-02-26 Gregory Bell , Koji Fujiwara

The edge expansion of a graph is the minimum quotient of the number of edges in a cut and the size of the smaller one among the two node sets separated by the cut. Bounding the edge expansion from below is important for bounding the…

Combinatorics · Mathematics 2007-05-23 Volker Kaibel

If a vertex $v$ in a graph $G$ has degree larger than the average of the degrees of its neighbors, we call it a groupie in $G$. In the current work, we study the behavior of groupie in random multipartite graphs with the link probability…

Combinatorics · Mathematics 2012-09-18 Marius Portmann , Hongyun Wang

The vertex isoperimetric number of a graph $G=(V,E)$ is the minimum of the ratio $|\partial_{V}U|/|U|$ where $U$ ranges over all nonempty subsets of $V$ with $|U|/|V|\le u$ and $\partial_{V}U$ is the set of all vertices adjacent to $U$ but…

Combinatorics · Mathematics 2025-11-18 Brett Kolesnik , Nick Wormald

Graphs of solutions to the minimal surface equation over simply connected domains with boundary values 0 can have at most exponential growth.

Differential Geometry · Mathematics 2026-04-22 Allen Weitsman

We prove upper bounds on the face numbers of simplicial complexes in terms on their girths, in analogy with the Moore bound from graph theory. Our definition of girth generalizes the usual definition for graphs.

Combinatorics · Mathematics 2009-06-04 Michael Goff

Let P_{n,m} denote the graph taken uniformly at random from the set of all planar graphs on {1,2,..., n} with exactly m(n) edges. We use counting arguments to investigate the probability that P_{n,m} will contain given components and…

Combinatorics · Mathematics 2011-01-27 Chris Dowden

Beyond-planarity focuses on the study of geometric and topological graphs that are in some sense nearly-planar. Here, planarity is relaxed by allowing edge crossings, but only with respect to some local forbidden crossing configurations.…

Discrete Mathematics · Computer Science 2017-12-29 Patrizio Angelini , Michael A. Bekos , Michael Kaufmann , Maximilian Pfister , Torsten Ueckerdt

We prove that random d-regular Cayley graphs of the symmetric group asymptotically almost surely have girth at least (log_{d-1}|G|)^{1/2}/2 and that random d-regular Cayley graphs of simple algebraic groups over F_q asymptotically almost…

Probability · Mathematics 2011-11-10 Alex Gamburd , Shlomo Hoory , Mehrdad Shahshahani , Aner Shalev , Balint Virag

Let $\Gamma$ denote a distance-regular graph with classical parameters $(D, b, \alpha, \beta)$ and $D\geq 3$. Assume the intersection numbers $a_1=0$ and $a_2\not=0$. We show $\Gamma$ is 3-bounded in the sense of the article [D-bounded…

Combinatorics · Mathematics 2007-09-06 Yeh-jong Pan , Chih-wen Weng

In this paper, we obtain lower bounds for the domination numbers of connected graphs with girth at least $7$. We show that the domination number of a connected graph with girth at least $7$ is either $1$ or at least…

Discrete Mathematics · Computer Science 2016-01-05 Yinglei Song

We enumerate rooted 2-connected and 3-connected surface maps with respect to vertices and edges. We also derive the bivariate version of the large face-width result for random 3-connected maps. These results are then used to derive…

Combinatorics · Mathematics 2010-03-16 E. A. Bender , Z. Gao

Let $G$ be a graph with the usual shortest-path metric. A graph is $\delta$-hyperbolic if for every geodesic triangle $T$, any side of $T$ is contained in a $\delta$-neighborhood of the union of the other two sides. A graph is chordal if…

Combinatorics · Mathematics 2015-05-22 A. Martínez-Pérez

In this paper we study the spectrum of the random geometric graph $G(n,r)$, in a regime where the graph is dense and highly connected. In the \erdren $G(n,p)$ random graph it is well known that upon connectivity the spectrum of the…

Probability · Mathematics 2020-04-13 Kartick Adhikari , Robert J. Adler , Omer Bobrowski , Ron Rosenthal

We resolve a conjecture of Hegarty regarding the number of edges in the square of a regular graph. If $G$ is a connected $d$-regular graph with $n$ vertices, the graph square of $G$ is not complete, and $G$ is not a member of two narrow…

Combinatorics · Mathematics 2011-12-22 Michael Goff

This paper gives sharp linear bounds on the genus of a normal surface in a triangulated compact, orientable 3--manifold in terms of the quadrilaterals in its cell decomposition---different bounds arise from varying hypotheses on the surface…

Geometric Topology · Mathematics 2016-07-20 William Jaco , Jesse Johnson , Jonathan Spreer , Stephan Tillmann

We consider three classes of random graphs: edge random graphs, vertex random graphs, and vertex-edge random graphs. Edge random graphs are Erdos-Renyi random graphs, vertex random graphs are generalizations of geometric random graphs, and…

Combinatorics · Mathematics 2010-10-14 Elizabeth Beer , James Allen Fill , Svante Janson , Edward R. Scheinerman

We obtain several new upper bounds of the odd graceful chromatic number of a graph $G$, which must be bipartite. Some of our bounds depend only on the number of the vertices of $G$ or the chromatic number of some graphs related to the…

Combinatorics · Mathematics 2025-09-03 Muhammad Afifurrahman , Fawwaz Fakhrurrozi Hadiputra

For a graph G, its rth power G^r has the same vertex set as G, and has an edge between any two vertices within distance r of each other in G. We give a lower bound for the number of edges in the rth power of G in terms of the order of G and…

Combinatorics · Mathematics 2012-02-29 Alexey Pokrovskiy

Thomassen conjectured that triangle-free planar graphs have an exponential number of $3$-colorings. We show this conjecture to be equivalent to the following statement: there exists a positive real $\alpha$ such that whenever $G$ is a…

Combinatorics · Mathematics 2017-09-20 Zdeněk Dvořák , Jean-Sébastien Sereni