Title
Top-k Overlapping Densest Subgraphs: Approximation and Complexity.
Abstract
A central problem in graph mining is finding dense subgraphs, with several applications in different fields, a notable example being identifying communities. While a lot of effort has been put on the problem of finding a single dense subgraph, only recently the focus has been shifted to the problem of finding a set of dens- est subgraphs. Some approaches aim at finding disjoint subgraphs, while in many real-world networks communities are often overlapping. An approach introduced to find possible overlapping subgraphs is the Top-k Overlapping Densest Subgraphs problem. For a given integer k u003e= 1, the goal of this problem is to find a set of k densest subgraphs that may share some vertices. objective function to be maximized takes into account both the density of the subgraphs and the distance between subgraphs in the solution. The Top-k Overlapping Densest Subgraphs problem has been shown to admit a 1/10-factor approximation algorithm. Furthermore, the computational complexity of the problem has been left open. In this paper, we present contributions concerning the approximability and the computational complexity of the problem. For the approximability, we present approximation algorithms that improves the approximation factor to 1/2 , when k is bounded by the vertex set, and to 2/3 when k is a constant. For the computational complexity, we show that the problem is NP-hard even when k = 3.
Year
Venue
Field
2018
ICTCS
Integer,Discrete mathematics,Approximation algorithm,Graph,Combinatorics,Disjoint sets,Vertex (geometry),Mathematics,Bounded function,Computational complexity theory
DocType
Volume
Citations 
Journal
abs/1809.02434
0
PageRank 
References 
Authors
0.34
1
4
Name
Order
Citations
PageRank
Riccardo Dondi18918.42
Mohammad Mehdi Hosseinzadeh201.01
Giancarlo Mauri32106297.38
Italo Zoppis43818.39