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One of the major challenges in applications related to social networks, computational biology, collaboration networks etc., is to efficiently search for similar patterns in their underlying graphs. These graphs are typically noisy and…

Social and Information Networks · Computer Science 2015-12-17 Kanigalpula Samanvi , Naveen Sivadasan

We consider the following natural generalization of Binary Search: in a given undirected, positively weighted graph, one vertex is a target. The algorithm's task is to identify the target by adaptively querying vertices. In response to…

Data Structures and Algorithms · Computer Science 2017-08-01 Ehsan Emamjomeh-Zadeh , David Kempe , Vikrant Singhal

We introduce and study the general setting of weighted search in which a number of targets, each with a certain weight, are hidden in a star-like environment that consists of $m$ infinite, concurrent rays, with a common origin. A mobile…

Data Structures and Algorithms · Computer Science 2021-05-05 Spyros Angelopoulos , Konstantinos Panagiotou

Since Grover's seminal work which provides a way to speed up combinatorial search, quantum search has been studied in great detail. We propose a new method for designing quantum search algorithms for finding a marked element in the state…

Quantum Physics · Physics 2012-08-07 R. Sufiani , N. Bahari

Quantum walk has been successfully used to search for targets on graphs with vertices identified as the elements of a database. This spacial search on a two-dimensional periodic grid takes $\mathcal{O}\left(\sqrt{N\log N}\right)$ oracle…

Quantum Physics · Physics 2025-03-07 Pulak Ranjan Giri

We consider the problem of searching for an unknown target vertex $t$ in a (possibly edge-weighted) graph. Each \emph{vertex-query} points to a vertex $v$ and the response either admits $v$ is the target or provides any neighbor $s\not=v$…

Data Structures and Algorithms · Computer Science 2024-01-26 Dariusz Dereniowski , Stefan Tiegel , Przemysław Uznański , Daniel Wolleb-Graf

Moving an autonomous agent through an unknown environment is one of the crucial problems for robotics and network analysis. Therefore, it received a lot of attention in the last decades and was analyzed in many different settings. The graph…

Computational Complexity · Computer Science 2018-04-23 Hans-Joachim Böckenhauer , Janosch Fuchs , Walter Unger

Given a simple graph $G$, we consider the node search problem with inert fugitive. We are interested in minimizing the maximum vertex occupation time, i.e. the maximum number of steps in which a vertex is occupied by a searcher during a…

Combinatorics · Mathematics 2021-03-05 Dariusz Dereniowski

We formulate Grover's unstructured search algorithm as a chiral quantum walk, where transitioning in one direction has a phase conjugate to transitioning in the opposite direction. For small phases, this breaking of time-reversal symmetry…

Quantum Physics · Physics 2015-09-22 Thomas G. Wong

When searching for a marked vertex in a graph, Szegedy's usual search operator is defined by using the transition probability matrix of the random walk with absorbing barriers at the marked vertices. Instead of using this operator, we…

Quantum Physics · Physics 2016-04-13 Raqueline A. M. Santos

We show that approximate similarity (near neighbour) search can be solved in high dimensions with performance matching state of the art (data independent) Locality Sensitive Hashing, but with a guarantee of no false negatives. Specifically,…

Data Structures and Algorithms · Computer Science 2018-06-28 Thomas Dybdahl Ahle

The terrain survey techniques of photogrammetry, LIDAR, Sonar or seismic studies are subject to limitation of shadow zones. It is not possible to capture the terrain pattern and requires interpolation and extrapolation for conformal mapping…

Geophysics · Physics 2022-07-25 Vedant Garg , Sabir B. Shafi Lone , Swetabh C. Singh

The search operation for a marked state by means of Grover's quantum searching algorithm is shown to be an element of group SU(2) which acts on a 2-dimensional space spanned by the marked state and the unmarked collective state. Based on…

Quantum Physics · Physics 2007-05-23 Sixia Yu , Chang-Pu Sun

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

We show that a simple local search gives a PTAS for the Feedback Vertex Set (FVS) problem in minor-free graphs. An efficient PTAS in minor-free graphs was known for this problem by Fomin, Lokshtanov, Raman and Sauraubh. However, their…

Data Structures and Algorithms · Computer Science 2019-06-04 Hung Le , Baigong Zheng

In this work we study the Friedmann-Lema\^{i}tre-Robertson-Walker cosmologies with arbitrary spatial curvature for the symmetric teleparallel theories of gravity, giving the first presentation of their coincident gauge form. Our approach…

General Relativity and Quantum Cosmology · Physics 2025-01-24 Erik Jensko

It is an easy observation that a natural greedy approach yields a $\left(d-O(1)\right)$-factor approximation algorithm for the maximum induced matching problem in $d$-regular graphs. The only considerable and non-trivial improvement of this…

Combinatorics · Mathematics 2017-08-08 Maximilian Fürst , Marilena Leichter , Dieter Rautenbach

Graph-structured data is central to many scientific and industrial domains, where the goal is often to optimize objectives defined over graph structures. Given the combinatorial complexity of graph spaces, such optimization problems are…

Optimization and Control · Mathematics 2025-09-25 Shiqiang Zhang , Ruth Misener

Nowadays, data is represented by vectors. Retrieving those vectors, among millions and billions, that are similar to a given query is a ubiquitous problem, known as similarity search, of relevance for a wide range of applications.…

Machine Learning · Computer Science 2023-07-26 Cecilia Aguerrebere , Ishwar Bhati , Mark Hildebrand , Mariano Tepper , Ted Willke

Graph matching---aligning a pair of graphs to minimize their edge disagreements---has received wide-spread attention from both theoretical and applied communities over the past several decades, including combinatorics, computer vision, and…