Christian Borgs

Christian Borgs is deputy managing director of the newly announced Microsoft Research New England lab in Cambridge, Massachusetts, which is scheduled to open in July 2008.  He is also an affiliate professor of mathematics at the University of Washington.  Before becoming deputy managing director of the New England lab, he was a principal researcher and co-manager of the Theory Group at Microsoft Research.
    His research is at the interface of mathematics, physics, and theoretical computer science.  In addition to his original area of expertise, the mathematical theory of first order phase transitions, his current interests include the following areas:

    Christian Borgs studied physics at the University of Munich, the University Pierre et Marie Curie in Paris, the Institut des Hautes Etudes in Bures-sur-Yvettes, and the Max-Planck-Institute for Physics in Munich.  He received his Ph.D. in mathematical physics from the University of Munich, held a postdoctoral fellowship at the ETH Zurich, and received his Habilitation in mathematical physics from the Free University in Berlin.  After his Habilitation he became the C4 Chair for Statistical Mechanics at the University of Leipzig, and in 1997 he joined Microsoft Research to co-found the Theory Group.
    He is well known for his work on the mathematical theory of first-order phase transitions and finite-size effects, for which he won the 1993 Karl-Scheel Prize of the German Physical Society.  Since joining Microsoft, Christian Borgs has become one of the world leaders in the study in phase transitions in combinatorial optimization, and more generally, the use of methods from statistical physics and probability theory in problems of interest to computer science and technology.  He is one of the top researchers in the modeling and analysis of self-organized networks, such as the Internet, the World Wide Web and social networks.
    Christian Borgs is the co-author of more than 90 research papers and is the co-inventor of more than 20 patents.  Among the honors he has received are a scholarship from the German National Merit Foundation, the above mentioned Karl-Scheel Prize, and the Heisenberg Fellowship of the German Research Council.  He has also given the prestigious Conference Board of Mathematical Sciences (CBMS) lecture series entitled "Statistical Physics Expansion Methods in Combinatorics and Computer Sciences." He has been a long-term visitor at Princeton, Harvard, and UCLA, and has twice been a member of the Institute for Advanced Study in Princeton.  Among the boards and councils on which he has served are the Council of the University of Leipzig, the Editorial Boards of the Journal of Statistical Physics and the SIAM Journal on Discrete Mathematics, and the Board of Trustees of the Institute for Pure and Applied Mathematics (IPAM).
    Christian Borgs is married to Jennifer Chayes, who is also at Microsoft Research, and with whom he collaborates on most of his scientific work.  In his rare spare time, he enjoys art, theatre and classical music, as well as skiing and swimming.

Selected Publications

Phase Transitions in Combinatorics and Computer Science

	Uniform boundedness of crossing probabilities implies hyperscaling (with J. T. Chayes, H. Kesten and J. Spencer) Random Structures and Algorithms 15, 368-413 (1999).
	The birth of the infinite cluster: Finite-size scaling in percolation (with J. T. Chayes, H. Kesten and J. Spencer) Communications in Mathematical Physics 224, 153-204 (2001).
	The scaling window of the 2-SAT transition (with B. Bollobas, J. T. Chayes, J.H. Kim and D.B. Wilson) Random Structures and Algorithms 18, 201-256 (2001).
	Sharp threshold and scaling window for the integer partitioning problem (with J. T. Chayes and B. Pittel) Proceedings of the 33rd annual ACM Symposium on the Theory of Computing (STOC), 330-336 (2001).
	Phase transition and finite-size scaling for the integer partitioning problem (with J. T. Chayes and B. Pittel) Random Structures and Algorithms 19, 247-288 (2001).
	Constrained integer partitions (with J. T. Chayes, S. Mertens and B. Pittel) Proceedings of the 6th Latin American Symposium on Theoretical Information (LATIN), 59-68, Lecture Notes in Computer Science 2976 (2004).
	Phase diagram for the constrained integer partitioning problem (with J. T. Chayes, S. Mertens and B. Pittel) Random Structures and Algorithms 24, 315-380 (2004).
	Random subgraphs of finite graphs: I. The scaling window under the triangle condition (with J. T. Chayes, R. van der Hofstad, G. Slade and J. Spencer) Random Structures and Algorithms 27, 137-184 (2005).
	Random subgraphs of finite graphs: II. The lace expansion and the triangle condition (with J. T. Chayes, R. van der Hofstad, G. Slade and J. Spencer) Annals of Probability 33, 1886-1944 (2005).
	Random subgraphs of finite graphs: III. The phase transition for the n-cube (with J. T. Chayes, R. van der Hofstad, G. Slade and J. Spencer) Combinatorica 26, 395-410 (2006).
	Proof of the local REM conjecture for number partitioning I: Constant energy scales (with J. T. Chayes, S. Mertens and C. Nair) Preprint (2005).
	Proof of the local REM conjecture for number partitioning II: Growing energy scales (with J. T. Chayes, S. Mertens and C. Nair) Preprint (2005).
	The Kesten-Stigum reconstruction bound is tight for roughly symmetric binary channels (with J. T. Chayes, E. Mossel and S. Roch) 47th Annual IEEE Symposium on Foundations of Computer Science (FOCS), 518-530 (2006).
	Percolation on dense graph sequenses (with B. Bollobas, J. T. Chayes and O. Riordan) Preprint (2007).

Networks and Graph Theory

	Directed scale-free graphs (with B. Bollobas, J. T. Chayes and O. Riordan) Proceedings of the 14th Annual ACM-SIAM Symposium on Discrete Algorithms (SODA), 132-139 (2003).
	Degree distribution of the FKP network model (with N. Berger, B. Bollobas, J. T. Chayes and O. Riordan) Proceedings of the 30th International Colloquium on Automata, Languages and Programming (ICALP), 725-738, Lecture Notes in Computer Science 2719 (2003).
	Exploring the community structure of newsgroups (with J. T. Chayes, M. Mahdian and A. Saberi) Proceedings of the 10th ACM SIGKDD International Conference on Knowledge, Discovery and Data Mining (KKD), 783-787 (2004).
	Newsgroup cluster data referred to in the above paper.
	Competition-induced preferential attachment (with N. Berger, J. T. Chayes, R. D'Souza and R. D. Kleinberg) Proceedings of the 31st International Colloquium on Automata, Languages and Programming (ICALP), 208-221, Lecture Notes in Computer Science 3142 (2004)
	Degree distribution of competition-induced preferential attachment graphs (with N. Berger, J. T. Chayes, R. D'Souza and R. D. Kleinberg) Combinatorics,  Probability and Computing 14, 697-721 (2005).
	On the spread of viruses on the Internet (with N. Berger, J. T. Chayes and A. Saberi) Proceedings of the 16th ACM-SIAM Symposium on Discrete Algorithm (SODA), 301-310 (2005).
	Graph limits and parameter testing (with J. T. Chayes, L. Lovasz, V. Sos, B. Szegedy and K. Vesztergombi) Proceedings of the 38rd Annual ACM Symposium on the Theory of Computing (STOC), 261-270 (2006).
	Counting graph homomorphisms (with J. T. Chayes, L. Lovasz, V. Sos, B. Szegedy and K. Vesztergombi) in Topics in Discrete Mathematics (eds. M. Klazar, J. Kratochvil, M. Loebl, J. Matousek, R. Thomas, P. Valtr), 315-371, Springer (2006).
	Convergent sequences of dense graphs I: Subgraph frequencies, metric properties and testing (with J. T. Chayes, L. Lovasz, V. Sos, and K. Vesztergombi) Preprint (2006).
	Convergent sequences of dense graphs II: Multiway Cuts and Statistical Physics (with J. T. Chayes, L. Lovasz, V. Sos, and K. Vesztergombi) Preprint (2007).
	Emergence of tempered preferential attachment from optimization (with N. Berger, J. T. Chayes, R. D'Souza and R. D. Kleinberg) Proceedings of the National Academy of Sciences (PNAS) 104, 6112-6117 (2007), cover article.
	Fitting the WHOIS Internet data A short note with technical details left out in the above paper.
	First to Market is not Everything: an Analysis of Preferential Attachment with Fitness (with J. T. Chayes, C. Daskalakis and S.Roch) Proceedings of the 39rd annual ACM Symposium on the Theory of Computing (STOC), 135-144 (2007).

Algorithmic Game Theory and Recommendation Systems

Multi-unit auctions with budget-constrained bidders (with J. T. Chayes, N. Immorlica, M. Mahdian and A. Saberi) Proceedings of the 6th ACM Conference on Electronic Commerce (EC), 44-51 (2005).

	Bid optimization in online advertisement auctions (with J. T. Chayes, O. Etesami, N. Immorlica and M. Mahdian) 2nd Workshop on Sponsored Search Auctions (2006) and Proceedings of the 16th international conference on World Wide Web (WWW), 531-540 (2007).
	The myth of the folk theorem (with J. T. Chayes, N. Immorlica, A. Kalai, V. Mirrokni and C. Papadimitriou) Proceedings of the 40st Annual ACM Symposium on the Theory of Computing (STOC) (2008).
	Local computation of pagerank contributions (with R. Andersen, , J. T. Chayes., J. Hopcroft, V. Mirrokni and S. Teng) Proceedings of the  5th Workshop on Algorithms and Models for the Web Graph (WAW), 150-165 (2007).
	Trust-based recommendation systems: An axiomatic approach (with R. Andersen, J. T. Chayes, U.Feige, A. Flaxman, A. Kalai, V. Mirrokni and M. Tennenholtz) Proceedings of the 17th international conference on World Wide Web (WWW) (2008).

Monte Carlo Markov Chains

	Torpid mixing of some Monte Carlo Markov Chain algorithms in statistical physics (with J. T. Chayes, A. Frieze, J.H. Kim, P. Tetali, E. Vigoda and V. Vu) Proceedings of the 40th Annual Symposium on Foundations of Computer Science (FOCS), 218-229 (1999).
	On the sampling problem for H-colorings on the hypercubic lattice (with J. T. Chayes, M. Dyer and P. Tetali) in Graphs, Morphisms and Statistical Physics (eds. J Nesetril and P Winkler),  DIMACS Series in Discrete Mathematics and Theoretical Computer Science 63, 13-28, American Mathematical Society (2004).

Zeros of Complex Partition Functions and Lee-Yang Theory

	Gibbs states of graphical representations of the Potts model with external fields (with M. Biskup, J. T. Chayes and R. Kotecky) Journal of Mathematical Physics 41, 1170-1210 (2000).
	General theory of Lee-Yang zeros in models with first-order phase transitions (with M. Biskup, J. T. Chayes, L. Kleinwaks and R. Kotecky) Physical Review Letters 84, 4794-4797 (2000).
	Partition function zeros at first-order phase transitions: A general analysis (with M. Biskup, J. T. Chayes, L. Kleinwaks and R. Kotecky) Communications in Mathematical Physics 251, 79-131 (2004).
	Partition function zeros at first-order phase transitions: Piorogov-Sinai theory (with M. Biskup, J. T. Chayes and R. Kotecky) Journal of Statistical Physics 116, 97-155 (2004).
	Absence of Zeros for the Chromatic Polynomial on Bounded Degree Graphs Combinatorics,  Probability and Computing 15, 63-74 (2006).