2015 Doctoral Dissertation Award

The Doctoral Dissertation Award Committee has awarded the Doctoral Dissertation Award in Distributed Computing 2015 to Dr. Leonid Barenboim.

Dr. Barenboim completed his thesis

“Efficient Network Utilization in Locality-Sensitive Distributed Algorithms”

on December 2013 under the supervision of Professor Michael Elkin at Ben Gurion University.

Leonid’s dissertation considers the LOCAL model, a distributed message passing model in which in time t, every node can learn the complete graph topology up to distance t in the network. In this model, the challenge is to compute some global result on a graph in time significantly less than it takes to propagate full information in the graph, that is, in time significantly less than the size or the diameter of the graph. This classical model captures the essence of graph locality issues in distributed network algorithms, and received much attention in the literature.

The dissertation studies several fundamental problems in this setting, including vertex coloring, edge coloring, maximal independent set, and network decomposition. For all of these problems, novel solutions are devised that significantly improve the best previously-known results. In particular, it provides a substantial improvement to the problem of distributed coloring, one of the key problems to study symmetry breaking in networks. The dissertation addresses a challenge which has been open over two decades: In particular, it reduces the number of colors achieved in deterministic logarithmic coloring time from quadratic to essentially linear. It also demonstrates the first constant-time locality-sensitive solution for an NP-complete problem. These and other results advance our knowledge in non-trivial ways. The results are deep, technically challenging, and innovative.

The award is sponsored jointly by the ACM Symposium on Principles of Distributed Computing (PODC) and the EATCS Symposium on Distributed Computing (DISC). This award is presented annually, with the presentation taking place alternately at PODC and DISC. This year 2015 it will be presented at PODC, to be held at Donostia-San Sebastián, Spain, July 21-23, 2015.

Distributed Computing Doctoral Dissertation Award Committee, 2015:

  • Shlomi Dolev, Ben Gurion University
  • Fabian Kuhn, University of Freiburg
  • Dahlia Malkhi (chair), VMware Research
  • Philipp Woelfel, University of Calgary