English
Related papers

Related papers: An Omega(n^2) Lower Bound for Random Universal Set…

200 papers

We say that collection of $n$-qudit gates is universal if there exists $N_0\geq n$ such that for every $N\geq N_0$ every $N$-qudit unitary operation can be approximated with arbitrary precision by a circuit built from gates of the…

Quantum Physics · Physics 2007-05-23 Gabor Ivanyos

We study vertex colorings of the square $G^2$ of an outerplanar graph $G$. We find the optimal bound of the inductiveness, chromatic number and the clique number of $G^2$ as a function of the maximum degree $\Delta$ of $G$ for all…

Combinatorics · Mathematics 2007-06-12 Geir Agnarsson , Magnus Mar Halldorsson

We establish relations between the bandwidth and the treewidth of bounded degree graphs G, and relate these parameters to the size of a separator of G as well as the size of an expanding subgraph of G. Our results imply that if one of these…

Combinatorics · Mathematics 2009-10-19 Julia Böttcher , Klaas P. Pruessmann , Anusch Taraz , Andreas Würfl

A well-known result by Kant [Algorithmica, 1996] implies that n-vertex outerplane graphs admit embedding-preserving planar straight-line grid drawings where the internal faces are convex polygons in $O(n^2)$ area. In this paper, we present…

Computational Geometry · Computer Science 2025-08-28 Michael A. Bekos , Giordano Da Lozzo , Fabrizio Frati , Giuseppe Liotta , Antonios Symvonis

The unitary evolution maps in closed chaotic quantum graphs are known to have universal spectral correlations, as predicted by random matrix theory. In chaotic graphs with absorption the quantum maps become non-unitary. We show that their…

Chaotic Dynamics · Physics 2013-08-13 Boris Gutkin , Vladimir Al. Osipov

We present a method for proving upper bounds on the eigenvalues of the graph Laplacian. A main step involves choosing an appropriate "Riemannian" metric to uniformize the geometry of the graph. In many interesting cases, the existence of…

Metric Geometry · Mathematics 2011-07-26 Jonathan A. Kelner , James R. Lee , Gregory N. Price , Shang-Hua Teng

It is known that for $\Omega \subset \mathbb{R}^{2}$ an unbounded convex domain and $H>0$, there exists a graph $G\subset \mathbb{R}^{3}$ of constant mean curvature $H$ over $\Omega $ with $\partial G=$ $\partial \Omega $ if and only if…

Differential Geometry · Mathematics 2020-01-24 Ari J. Aiolfi , Patrícia Klaser

Let $f(n,k)$ be the minimum number of edges that must be removed from some complete geometric graph $G$ on $n$ points, so that there exists a tree on $k$ vertices that is no longer a planar subgraph of $G$. In this paper we show that…

The momentum spectrum of a periodic network (quantum graph) has a band-gap structure. We investigate the relative density of the bands or, equivalently, the probability that a randomly chosen momentum belongs to the spectrum of the periodic…

Mathematical Physics · Physics 2013-11-21 Ram Band , Gregory Berkolaiko

We describe a very simple condition that is necessary for the universal rigidity of a complete bipartite framework $(K(n,m),p,q)$. This condition is also sufficient for universal rigidity under a variety of weak assumptions, such as general…

Metric Geometry · Mathematics 2016-10-14 Robert Connelly , Steven J. Gortler

Let $X_N$ be an $N$-dimensional subspace of $L_2$ functions on a probability space $(\Omega, \mu)$ spanned by a uniformly bounded Riesz basis $\Phi_N$. Given an integer $1\leq v\leq N$ and an exponent $1\leq q\leq 2$, we obtain universal…

Functional Analysis · Mathematics 2021-07-27 Feng Dai , V. Temlyakov

In this paper we are concerned with the problem of finding hypersurfaces of constant curvature and prescribed boundary in the Euclidean space, using the theory of fully nonlinear elliptic equations. We prove that if the given data admits a…

Differential Geometry · Mathematics 2017-06-02 Flávio F. Cruz

We show that any outerplanar graph admits a planar straightline drawing such that the length ratio of the longest to the shortest edges is strictly less than 2. This result is tight in the sense that for any $\epsilon > 0$ there are…

Computational Geometry · Computer Science 2017-09-04 Sylvain Lazard , William Lenhart , Giuseppe Liotta

Chung and Graham [J. London Math. Soc. 1983] claimed to prove that there exists an $n$-vertex graph $G$ with $ \frac{5}{2}n \log_2 n + O(n)$ edges that contains every $n$-vertex tree as a subgraph. Frati, Hoffmann and T\'oth [Combin.…

Combinatorics · Mathematics 2026-02-04 Neel Kaul , Jaehoon Kim , Minseo Kim , David R. Wood

In this paper, we study the outerplanarity of planar graphs, i.e., the number of times that we must (in a planar embedding that we can initially freely choose) remove the outerface vertices until the graph is empty. It is well-known that…

Data Structures and Algorithms · Computer Science 2024-07-08 Therese Biedl , Debajyoti Mondal

The genus of a graph is a topological invariant that measures the minimum genus of a surface on which the graph can be embedded without any edges crossing. Graph genus plays a fundamental role in topological graph theory, used to classify…

Combinatorics · Mathematics 2023-01-31 Lucas Blakeslee

Starting from an arbitrary sequence of polygons whose total perimeter is $2n$, we can build an (oriented) surface by pairing their sides in a uniform fashion. Chmutov and Pittel (arXiv:1503.01816) have shown that, regardless of the…

Probability · Mathematics 2019-02-05 Thomas Budzinski , Nicolas Curien , Bram Petri

We show that for any constant $\Delta \ge 2$, there exists a graph $G$ with $O(n^{\Delta / 2})$ vertices which contains every $n$-vertex graph with maximum degree $\Delta$ as an induced subgraph. For odd $\Delta$ this significantly improves…

Combinatorics · Mathematics 2019-02-20 Noga Alon , Rajko Nenadov

Embedding graphs in a geographical or latent space, i.e.\ inferring locations for vertices in Euclidean space or on a smooth manifold or submanifold, is a common task in network analysis, statistical inference, and graph visualization. We…

Computational Geometry · Computer Science 2022-05-18 Varsha Dani , Josep Díaz , Thomas P. Hayes , Cristopher Moore

We study straight-line drawings of planar graphs with prescribed face areas. A plane graph is 'area-universal' if for every area assignment on the inner faces, there exists a straight-line drawing realizing the prescribed areas. For…

Computational Geometry · Computer Science 2018-09-05 Linda Kleist