# Algorithms and Geometry Collaboration: Former Principal Investigators

### Moses Charikar, Ph.D.

Moses Charikar was a founding PI in the Collaboration during the 2014/15 year. He became a professor of computer science at Stanford University in August 2015. He received his Ph.D. from Stanford University in 2000. He joined Princeton in 2001 after spending a year at Google Research. He is broadly interested in the design and analysis of algorithms, with an emphasis on approximation algorithms for NP-hard problems, metric embeddings and algorithmic techniques for massive data sets.

His research is focused on developing an increased understanding of mathematical programming methods using linear programming and semidefinite programming, which have been very useful in the design of approximation algorithms. He has used these methods to show lower bounds for dimension reduction and in the design of locality sensitive hash functions — primitives for compact data representation and efficient search data structures in high dimensional spaces. For the latter work, he was jointly awarded the 2012 ACM Paris Kanellakis Theory and Practice Award.

### Elchanan Mossel, Ph.D.

Elchanan Mossel became a professor of mathematics at MIT in 2016. He was previously a professor of statistics at the University of Pennsylvania. Elchanan was awarded a Ph.D. in mathematics from Hebrew University of Jerusalem. Since then, he was appointed as a postdoc in the Theory Group at Microsoft Research Redmond, an Alfred P. Sloan Research Fellow, a Miller Research Fellow at University of California, Berkeley, a professor of mathematics, applied mathematics and computer science at the Weizmann Institute of Science and a professor of statistics and computer science at University of California, Berkeley.

He studies fundamental problems in probability and analysis, computational complexity and algorithms, as well as applications to machine learning, Markov chain Monte Carlo methods, social choice and networks, and computational biology.