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Related papers: Quantum query complexity of graph connectivity

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Let $A_q(n,d)$ be the maximum order (maximum number of codewords) of a $q$-ary code of length $n$ and Hamming distance at least $d$. And let $A(n,d,w)$ that of a binary code of constant weight $w$. Building on results from algebraic graph…

Information Theory · Computer Science 2008-07-01 Salim Y. El Rouayheb , C. N. Georghiades , E. Soljanin , A. Sprintson

Local Search problem, which finds a local minimum of a black-box function on a given graph, is of both practical and theoretical importance to combinatorial optimization, complexity theory and many other areas in theoretical computer…

Quantum Physics · Physics 2007-05-23 Shengyu Zhang

Let $q(G)$ denote the $Q$-index of a graph $G$, which is the largest signless Laplacian eigenvalue of $G$. We prove best possible upper bounds of $q(G)$ and best possible lower bounds of $q(\overline{G})$ for a connected graph $G$ to be…

Combinatorics · Mathematics 2019-04-11 Huicai Jia , Hong-Jian Lai , Ruifang Liu , Ju Zhou

We consider the connected variant of the classic mixed search game where, in each search step, cleaned edges form a connected subgraph. We consider graph classes with bounded connected (and monotone) mixed search number and we deal with the…

Combinatorics · Mathematics 2015-08-12 Micah J. Best , Arvind Gupta , Dimitrios M. Thilikos , Dimitris Zoros

The algebraic connectivity $a(G)$ of a graph $G$ is defined as the second smallest eigenvalue of its Laplacian matrix $L(G)$. It also admits a variational characterization as the minimum of a quadratic form associated with $L(G)$, subject…

Combinatorics · Mathematics 2025-07-30 M. Rajesh Kannan , Rahul Roy

We investigate the problem of detecting correlation between two Erd\H{o}s-R\'enyi graphs $G(n,p)$, formulated as a hypothesis testing problem: under the null hypothesis, the two graphs are independent, while under the alternative…

Social and Information Networks · Computer Science 2026-03-18 Dong Huang , Pengkun Yang

Given a connected graph $G$ on $n$ vertices and a positive integer $k\le n$, a subgraph of $G$ on $k$ vertices is called a $k$-subgraph in $G$. We design combinatorial approximation algorithms for finding a connected $k$-subgraph in $G$…

Discrete Mathematics · Computer Science 2015-01-30 Xujin Chen , Xiaodong Hu , Changjun Wang

We give logarithmic lower bounds for the approximability of the Minimum Dominating Set problem in connected (alpha,beta)-Power Law Graphs. We give also a best up to now upper approximation bound on the problem for the case of the parameters…

Computational Complexity · Computer Science 2012-12-17 Mikael Gast , Mathias Hauptmann , Marek Karpinski

Given a partition of a graph into connected components, the membership oracle asserts whether any two vertices of the graph lie in the same component or not. We prove that for $n\ge k\ge 2$, learning the components of an $n$-vertex hidden…

Machine Learning · Computer Science 2022-06-20 Xizhi Liu , Sayan Mukherjee

We give unconditional parameterized complexity lower bounds on pure dynamic programming algorithms - as modeled by tropical circuits - for connectivity problems such as the Traveling Salesperson Problem. Our lower bounds are higher than the…

Computational Complexity · Computer Science 2025-12-30 Kacper Kluk , Jesper Nederlof

The graph reconstruction problem has been extensively studied under various query models. In this paper, we propose a new query model regarding the number of connected components, which is one of the most basic and fundamental graph…

Data Structures and Algorithms · Computer Science 2025-06-24 Hadley Black , Arya Mazumdar , Barna Saha , Yinzhan Xu

The edge list model is arguably the simplest input model for graphs, where the graph is specified by a list of its edges. In this model, we study the quantum query complexity of three variants of the triangle finding problem. The first asks…

Quantum Physics · Physics 2026-05-29 Amin Shiraz Gilani , Daochen Wang , Pei Wu , Xingyu Zhou

A topological graph is $k$-quasi-planar if it does not contain $k$ pairwise crossing edges. A 20-year-old conjecture asserts that for every fixed $k$, the maximum number of edges in a $k$-quasi-planar graph on $n$ vertices is $O(n)$. Fox…

Combinatorics · Mathematics 2016-01-28 Andrew Suk , Bartosz Walczak

We study the problem of deterministic approximate counting of matchings and independent sets in graphs of bounded connective constant. More generally, we consider the problem of evaluating the partition functions of the monomer-dimer model…

Data Structures and Algorithms · Computer Science 2014-10-10 Alistair Sinclair , Piyush Srivastava , Daniel Štefankovič , Yitong Yin

We introduce a notion of curvature on finite, combinatorial graphs. It can be easily computed by solving a linear system of equations. We show that graphs with curvature bounded below by $K>0$ have diameter bounded by $\mbox{diam}(G) \leq…

Combinatorics · Mathematics 2022-09-07 Stefan Steinerberger

The classic lower bound of Kuhn, Moscibroda and Wattenhofer [JACM 2016] states that approximate maximum matching and approximate vertex cover (among other problems) in the LOCAL model require $\Omega(\min\{\sqrt{\frac{\log n}{\log\log n}},…

Data Structures and Algorithms · Computer Science 2026-05-14 Peter Davies-Peck

We show that a large fraction of the data-structure lower bounds known today in fact follow by reduction from the communication complexity of lopsided (asymmetric) set disjointness. This includes lower bounds for: * high-dimensional…

Data Structures and Algorithms · Computer Science 2010-10-20 Mihai Patrascu

We show lower bounds of $\Omega(\sqrt{n})$ and $\Omega(n^{1/4})$ on the randomized and quantum communication complexity, respectively, of all $n$-variable read-once Boolean formulas. Our results complement the recent lower bound of…

Computational Complexity · Computer Science 2009-09-01 Rahul Jain , Hartmut Klauck , Shengyu Zhang

We propose a combinatorial optimisation model called Limited Query Graph Connectivity Test. We consider a graph whose edges have two possible states (On/Off). The edges' states are hidden initially. We could query an edge to reveal its…

Data Structures and Algorithms · Computer Science 2023-12-19 Mingyu Guo , Jialiang Li , Aneta Neumann , Frank Neumann , Hung Nguyen

Consider a generalization of the classical binary search problem in linearly sorted data to the graph-theoretic setting. The goal is to design an adaptive query algorithm, called a strategy, that identifies an initially unknown target…

Data Structures and Algorithms · Computer Science 2020-05-04 Dariusz Dereniowski , Aleksander Łukasiewicz , Przemysław Uznański