English
Related papers

Related papers: Isometric Diamond Subgraphs

200 papers

We complete the complexity classification by degree of minimizing a polynomial over the integer points in a polyhedron in $\mathbb{R}^2$. Previous work shows that optimizing a quadratic polynomial over the integer points in a polyhedral…

Optimization and Control · Mathematics 2015-05-07 Alberto Del Pia , Robert Hildebrand , Robert Weismantel , Kevin Zemmer

We call a digraph {\em $h$-semicomplete} if each vertex of the digraph has at most $h$ non-neighbors, where a non-neighbor of a vertex $v$ is a vertex $u \neq v$ such that there is no edge between $u$ and $v$ in either direction. This…

Data Structures and Algorithms · Computer Science 2015-07-08 Kenta Kitsunai , Yasuaki Kobayashi , Hisao Tamaki

De Berg et al. in [SICOMP 2020] gave an algorithmic framework for subexponential algorithms on geometric graphs with tight (up to ETH) running times. This framework is based on dynamic programming on graphs of weighted treewidth resulting…

Data Structures and Algorithms · Computer Science 2021-07-15 Fedor V. Fomin , Petr A. Golovach , Tanmay Inamdar , Saket Saurabh

It is $\mathsf{NP}$-hard to determine the minimum number of branching vertices needed in a single-source distance-preserving subgraph of an undirected graph. We show that this problem can be solved in polynomial time if the input graph is…

Data Structures and Algorithms · Computer Science 2018-10-30 Kshitij Gajjar , Jaikumar Radhakrishnan

A vertex of a plane digraph is bimodal if all its incoming edges (and hence all its outgoing edges) are consecutive in the cyclic order around it. A plane digraph is bimodal if all its vertices are bimodal. Bimodality is at the heart of…

Data Structures and Algorithms · Computer Science 2023-08-31 Walter Didimo , Fedor V. Fomin , Petr A. Golovach , Tanmay Inamdar , Stephen Kobourov , Marie Diana Sieper

We represent vector bundles over a regular algebraic curve as pairs of lattices over the maximal orders of its function field and we give polynomial time algorithms for several tasks: computing determinants of vector bundles, kernels and…

Algebraic Geometry · Mathematics 2024-08-05 Mickaël Montessinos

Metric graphs are ubiquitous in science and engineering. For example, many data are drawn from hidden spaces that are graph-like, such as the cosmic web. A metric graph offers one of the simplest yet still meaningful ways to represent the…

Computational Geometry · Computer Science 2017-12-05 Tamal K. Dey , Dayu Shi , Yusu Wang

A subgraph of the $n$-dimensional hypercube is called 'layered' if it is a subgraph of a layer of some hypercube. In this paper we show that there exist subgraphs of the cube of arbitrarily large girth that are not layered. This answers a…

Combinatorics · Mathematics 2024-04-30 Natalie Behague , Imre Leader , Natasha Morrison , Kada Williams

Many real world networks are considered temporal networks, in which the chronological ordering of the edges has importance to the meaning of the data. Performing temporal subgraph matching on such graphs requires the edges in the subgraphs…

Data Structures and Algorithms · Computer Science 2018-01-25 Patrick Mackey , Katherine Porterfield , Erin Fitzhenry , Sutanay Choudhury , George Chin

Consider two planar graphs which are subject to edge insertions and deletions. We show that whether the two graphs are isomorphic can be maintained with first-order logic formulas and auxiliary data of polynomial size. This places the…

Logic in Computer Science · Computer Science 2026-04-27 Samir Datta , Asif Khan , Felix Tschirbs , Nils Vortmeier , Thomas Zeume

We consider embeddings of 3-regular graphs into 3-dimensional Cartesian coordinates, in such a way that two vertices are adjacent if and only if two of their three coordinates are equal (that is, if they lie on an axis-parallel line) and…

Computational Geometry · Computer Science 2015-07-16 David Eppstein

We study the computational model of polygraphs. For that, we consider polygraphic programs, a subclass of these objects, as a formal description of first-order functional programs. We explain their semantics and prove that they form a…

Logic in Computer Science · Computer Science 2015-07-01 Guillaume Bonfante , Yves Guiraud

Given a dynamic graph subject to insertions and deletions of edges, a natural question is whether the graph presently admits a planar embedding. We give a deterministic fully-dynamic algorithm for general graphs, running in amortized…

Data Structures and Algorithms · Computer Science 2019-12-11 Jacob Holm , Eva Rotenberg

The modular design of planar phased array antennas with hexagonal apertures is addressed by means of innovative diamond-shaped tiling techniques. Both tiling configuration and subarray coefficients are optimized to fit user-defined…

Signal Processing · Electrical Eng. & Systems 2022-01-02 P. Rocca , N. Anselmi , A. Polo , A. Massa

This paper is a self-contained development of an invariant of graphs embedded in three-dimensional Euclidean space using the Jones polynomial and skein theory. Some examples of the invariant are computed. An unlinked embedded graph is one…

Quantum Algebra · Mathematics 2007-05-23 John W. Barrett

We present an algorithm to compute path homology for simple digraphs, and use it to topologically analyze various small digraphs en route to an analysis of complex temporal networks which exhibit such digraphs as underlying motifs. The…

Social and Information Networks · Computer Science 2021-01-15 Samir Chowdhury , Steve Huntsman , Matvey Yutin

We give the first polynomial-time algorithms on graphs of bounded maximum induced matching width (mim-width) for problems that are not locally checkable. In particular, we give $n^{\mathcal{O}(w)}$-time algorithms on graphs of mim-width at…

Data Structures and Algorithms · Computer Science 2017-09-29 Lars Jaffke , O-joung Kwon , Jan Arne Telle

Nontrivial isometric embeddings for flat metrics (i.e., those which are not just planes in the ambient space) can serve as useful tools in the description of gravity in the embedding gravity approach. Such embeddings can additionally be…

General Relativity and Quantum Cosmology · Physics 2021-12-21 S. A. Paston , T. I. Zaitseva

In this paper we resolve the complexity of the isomorphism problem on all but finitely many of the graph classes characterized by two forbidden induced subgraphs. To this end we develop new techniques applicable for the structural and…

Discrete Mathematics · Computer Science 2014-11-10 Pascal Schweitzer

Many real-world networks of interest are embedded in physical space. We present a new random graph model aiming to reflect the interplay between the geometries of the graph and of the underlying space. The model favors configurations with…

Probability · Mathematics 2017-06-14 Jean-Christophe Mourrat , Daniel Valesin