Title
Retracting Graphs to Cycles.
Abstract
We initiate the algorithmic study of retracting a graph into a cycle in the graph, which seeks a mapping of the graph vertices to the cycle vertices, so as to minimize the maximum stretch of any edge, subject to the constraint that the restriction of the mapping to the cycle is the identity map. This problem has its roots in the rich theory of retraction of topological spaces, and has strong ties to well-studied metric embedding problems such as minimum bandwidth and 0-extension. Our first result is an O(min{k, sqrt{n}})-approximation for retracting any graph on n nodes to a cycle with k nodes. We also show a surprising connection to Sperneru0027s Lemma that rules out the possibility of improving this result using natural convex relaxations of the problem. Nevertheless, if the problem is restricted to planar graphs, we show that we can overcome these integrality gaps using an exact combinatorial algorithm, which is the technical centerpiece of the paper. Building on our planar graph algorithm, we also obtain a constant-factor approximation algorithm for retraction of points in the Euclidean plane to a uniform cycle.
Year
Venue
Field
2019
ICALP
Identity function,Discrete mathematics,Approximation algorithm,Combinatorics,Embedding,Topological space,Vertex (geometry),Regular polygon,Euclidean geometry,Mathematics,Planar graph
DocType
Citations 
PageRank 
Journal
0
0.34
References 
Authors
0
6
Name
Order
Citations
PageRank
Samuel Haney192.47
Mehraneh Liaee200.34
Bruce M. Maggs33592368.31
Debmalya Panigrahi426935.78
Rajmohan Rajaraman52038250.08
Ravi Sundaram676272.13