Sybil attacks in which an adversary forges a potentially unbounded number of identities are
a danger to distributed systems and online social networks. The goal of sybil defense is to …

A basic fact in spectral graph theory is that the number of connected components in an
undirected graph is equal to the multiplicity of the eigenvalue zero in the Laplacian matrix of …

We study the problem of graph clustering where the goal is to partition a graph into clusters,
ie disjoint subsets of vertices, such that each cluster is well connected internally while …

Given a subset A of vertices of an undirected graph G, the cut-improvement problem asks us
to find a subset S that is similar to A but has smaller conductance. An elegant algorithm for …

We develop a new algorithm for the turnstile heavy hitters problem in general turnstile
streams, the EXPANDERSKETCH, which finds the approximate top-k items in a universe of …

A hypergraph is a useful combinatorial object to model ternary or higher-order relations
among entities. Clustering hypergraphs is a fundamental task in network analysis. In this …

Graph clustering has many important applications in computing, but due to growing sizes of
graphs, even traditionally fast clustering methods such as spectral partitioning can be …

Nowadays, large-scale graph data is being generated in a variety of real-world applications,
from social networks to co-authorship networks, from protein-protein interaction networks to …

Motivated by applications of large-scale graph clustering, we study random-walk-based
LOCAL algorithms whose running times depend only on the size of the output cluster, rather …

We initiate the study of fast dynamic algorithms for graph sparsification problems and obtain
fully dynamic algorithms, allowing both edge insertions and edge deletions, that take …