Éva Tardos

Professor

Department of Computer Science, chair
4130 Upson Hall
Cornell University
Ithaca, NY 14853
phone: (607) 255-0984
fax: (607) 255-4428
Email: eva@cs.cornell.edu .

Current Ph.D. students

• Thanh Nguyen
• Georgios Piliouras

Past Ph.D. students

• Zoya Svitkina (2007)
• Ara Hayrapetyan (2007)
• Tom Wexler (2006)
• Martin Pal (2004)
• Aaron Archer (2004)
• Tim Roughgarden (2002)
• Vardges Melkonian (2002)
• Kevin Wayne (1999)
• Wee Liang Heng (1998)
• Lisa Fleischer (1997)
• Bruce Hoppe (1995)

Algorithm Design and Algorithmic Game Theory. Algorithmic game theory, an emerging new area of designing systems and algorithms for selfish users. My research focuses algorithms and games on graphs or networks. I am mostly interested in designing algorithms and games that provide provably close-to-optimal results.

Areas of interest

• Games in Networks
• Price of anarchy
• Network design algorithms and games
• mechanism design
• Classification
• Clustering and facility location
• Scheduling
• Routing paths and packets in networks
• Finding cuts in graphs with applications in visition

Recent Surveys

•  E. Tardos and V. Vazirani, Basic Solution Concepts and Computational Issues in Games, in Algorithmic Game Theory (to be published by Cambridge University Press, expected 2007).
• T. Roughgarden and E. Tardos: Introduction to the Inefficiency of Equilibria.  in Algorithmic Game Theory (to be published by Cambridge University Press, expected 2007).
• E. Tardos and T. Wexler: Network Formation Games, in Algorithmic Game Theory (to be published by Cambridge University Press, expected 2007).
• Games in Networks, presented at STOC 2004.
• Tutorial on Approximation Algorithms, presented at FOCS 2002.

Textbook on Algorithms

• J. Kleinberg, E. Tardos. Algorithm Design. Addison-Wesley, 2005.

Courses

• Algorithmic Game Theory, CS 684, spring, 2008, fall 2005, spring 2004.
• Discrete Structures, CS280, spring 2005
• Introduction to Theory of Computing, CS 481 fall 2004
• Design and Analysis of Algorithms, CS 681, fall 2000, fall 2002, fall 2003, fall 2006.
• Introduction to Algorithms, CS 482, spring 1999, 2001, 2002
• Approximation and Network Algorithms, CS 684, fall 2001
• Seminar on Approximation Algorithms, spring 1999
• Mathematical Programming, OR 630, fall 1998
• Optimization,  OR 321, spring 1998
• Data Structures, CS 410, fall 1997

Current Project

• Algorithmic Game Theory, co-edited with Noam Nisan, Tim Roughgarden, and Vijay Vazirani (to be published by Cambridge University Press, expected October 2007.)

Selected Recent Publications

Network Games and extensions

• T. Roughgarden and E. Tardos: How Bad is Selfish Routing? Journal of the ACM, 2002, Volume 49 ,  Issue 2. Preliminary version has appeared in the Proceedings of the 41st Annual IEEE Symposium on the Foundations of Computer Science, 2000. 
• T. Roughgarden and E. Tardos: Bounding the Inefficiency of Equilibria in Nonatomic Congestion Games. Games and Economic Behaviour, Volume 47, Issue 2, May 2004, Pages 389-403.
• H. Lin, T. Roughgarden, and E. Tardos, Bounding Braess's Paradox, Proceedings of the 15th Annual ACM-SIAM Symposium on Discrete Algorithms, 2004.
• H. Lin, T. Roughgarden,  E. Tardos, and A. Walkover. Braess's Paradox, Fibonacci Numbers, and Exponential Inapproximability, in the 32nd International Colloquium on Automata, Languages and Programming (ICALP,05) July, 2005.
• E. Anshelevich, A. Dasgupta, É. Tardos, T. Wexler, Near-optimal network design with selfish agents, in the proceedings of the Annual ACM Symposium on the Theory of Computing, 2003.
• E. Anshelevich, A. Dasgupta, J. Kleinberg, E. Tardos, T. Wexler, and T. Roughgarden. The Price of Stability for Network Design with Fair Cost Allocation, Annual IEEE Symposium on Foundations of Computer Science, 2004. 
• Eva Tardos. Network Games. Proceedings of the Annual ACM Symposium on Theory of Computing, 2004.
• Ara Hayrapetyan, Éva Tardos and Tom Wexler - A Network Pricing Game for Selfish Traffic  Distributed Computing, (PODC'05 special issue).Preliminary version appeared in the Proceedings of
  24th Annual ACM SIGACT-SIGOPS Symposium on Principles of Distributed Computing (PODC'05), July 2005.
• Ara Hayrapetyan, Éva Tardos and Tom Wexler: Effect of Collusion in Congestion Games. Proceedings of the ACM Symposium on the Theory of Computing (STOC), 2006.
• L. Blume, D. Easley, J. Kleinberg and E. Tardos: Trading Networks with Price-Setting Agents to appear in EC'07.

Mechanism Design

• A. Archer and 'E. Tardos: Frugal Path mechanisms, to appear in Transaction on Algorithms. Preliminary version appeared in the Proceedings of the Annual ACM-SIAM Symposium on Discrete Algorithms, 2002, pp. 991-999.
• A. Archer  and E. Tardos: Truthful mechanisms for one-parameter agents, Proceedings of the 42nd IEEE Symposium on Foundations of Computer Science (2001) 482-491.   
• A. Archer, Christos Papadimitriou, Kunal Talwar, Eva Tardos: An approximate truthful mechanism for combinatorial auctions with single parameter agents. Internet Mathematics, Volume 1 Issue 2, 2004. Prleiminary version appeared in the Proceedings of  the Annual ACM-SIAM Symposium on Discrete Algorithms, 2003, pp. 205 - 214. 
• M. Pal and E. Tardos: Group Strategyproof Mechanisms via Primal-Dual Algorithms, in the Proceedings of the Annual IEEE Symposium on Foundations of Computer Science, 2003.
• A. Gupta, A. Srinivasan, and E. Tardos. Cost-Sharing Mechanisms for Network Design. Proceedings of APPROX 2004.

Social Networks

• David Kempe, Jon Kleinberg, Éva Tardos: Maximizing the Spread of Influence in a Social Network.
  Proceedings of  KDD 2003, Washington DC.
• David Kempe, Jon Kleinberg, Éva Tardos: Influential Nodes in a Diffusion Model for Social Networks. In Proceedings of ICALP 2005, Lisboa, Portugal.

Classification

• J. Kleinberg and E. Tardos. Approximation Algorithms for Classification Problems with Pairwise Relationships:
  Metric Partitioning and Markov Random Fields, Journal of the ACM, 2002, Volume 49,   Issue 5, pp, 616-639. Preliminary version has appeared in the Proceedings of the 40th Annual IEEE Symposium on the Foundations of Computer Science, 1999.
• A. Gupta and E. Tardos: A Constant Factor Approximation Algorithm for a Class of Classification Problems, In the Proceedings of the ACM Symposium on the Theory of Computing, May 2000.
• A. Archer J. Fakcharoenphol, C. Harrelson, R. Krauthgamer, K. Talvar and E. Tardos: Approximate Classification via Earthmover Metrics, in the Proceedings of the 15th Annual ACM-SIAM Symposium on Discrete Algorithms, 2004.

Clustering and facility location

• Zoya Svitkina and Eva Tardos: Facility Location with Hierarchical Facility Costs. in the Proceedings of the 17th Annual ACM-SIAM Symposium on Discrete Algorithms, 2006.
• Martin Pál, Éva Tardos, Tom Wexler. Facility Location with Hard Capacities. In the Proceedings of the 42nd Annual IEEE Symposium on the Foundations of Computer Science, 2001.
• D. B. Shmoys,  E. Tardos and K. Aardal. Approximation algorithms for the facility location problem.
  In the Proc. of the 29th Annual ACM Symposium on the Theory of Computing, 1997, pp. 265-274.
• M. Charikar, S. Guha, E. Tardos and D. Shmoys. A constant-factor approximation algorithm for the k-median problem. To appear in the JCSS, preliminary version has appeared in the  Proc. of the 31st Annual ACM Symposium on the Theory of Computing, 1999, pp. 1-10.
• Ara Hayrapetyan, Chaitanya Swamy and Éva Tardos: Network Design for Information Networks, ACM-SIAM Symposium on Discrete Algorithms (SODA), 2005

Network Design

• M. Goemans, A. Goldberg, S. Plotkin, D. Shmoys, E. Tardos, and D. Williamson: Improved approximation algorithms for network design problems. In the proceeding of the 5th Annual ACM-SIAM Symposium on Discrete Algorithms, January 1994, pp. 223-232. ORIE TR-1116.
• V. Melkonian and E. Tardos. Approximation Algorithms for a Directed Network Design Problem.
  In the Proceedings of the 7th International Integer Programming and Combinatorial Optimization Conference (IPCO'99), Graz, 1999.
• Ara Hayrapetyan, Chaitanya Swamy and Éva Tardos - Network Design for Information Networks
• Zoya Svitkina and Éva Tardos: Facility Location with Hierarchical Facility Costs.

Routing Disjoint Paths and Packets in Networks

• J. Kleinberg, Y. Rabani, and E. Tardos. Fairness in Routing and Load Balancing, In the Proceedings of the 40th Annual IEEE Symposium on the Foundations of Computer Science, 1999.
• J. Kleinberg and E. Tardos: Approximations for the Disjoint Paths Problem in High-Diameter Planar Networks, Journal of Computer and System Sciences STOC'95 special issue, vol 57, pp 61-73, 1998. Preliminary version has appeared in the Proceedings of the 27th Annual ACM Symposium on the  Theory of Computing, 1995, pp. 26-35. ORIE TR-1121.
• J. Kleinberg and E. Tardos: Disjoint Paths in Densely Embedded Graphs, In the Proceedings of the 34th Annual IEEE Symposium on the Foundations of Computer Science, 1995, pp. 52-61.
• Y. Rabani and E. Tardos: Distributed Packet Switching in Arbitrary Networks, in the 28th ACM Symposium on Theory of Computing, May, 1996, pp. 366-376.

Scheduling

• D. Shmoys and E. Tardos, An approximation algorithm for the generalized assignment problem. Mathematical Programming A 62, 1993, 461-474.  Preliminary version has appeared in the proceeding of the 4th Annual ACM-SIAM Symposium on Discrete Algorithms, January 1993.
• A. Goel, M. Henzinger, S. Plotkin, and E. Tardos. Scheduling Data Transfers in a Network and the Set Scheduling Problem In the  Proc. of the 31st Annual ACM Symposium on the Theory of Computing, 1999, pp. 189-199.

Generalized Flow

• A. Goldberg, S. Plotkin, E. Tardos: Combinatorial algorithms for the generalized circulation problem, Mathematics of Operations Research, 16/2, 1991, 351-381. Preliminary version has appeared in the Proceedings of the 29th Annual IEEE Symposium on the Foundations of Computer Science (1988), 432-443.
• E. Tardos and K. Wayne. Simple Generalized Maximum Flow Algorithms. Proceedings of the 6th International Integer Programming and Combinatorial Optimization Conference   (IPCO'98), Houston, 1998, pp. 310-324.

Packing and Covering Algorithms

• P. Klein, S. Plotkin, C. Stein and E. Tardos, Faster approximation algorithms for the unit capacity concurrent flow problem with applications to routing and finding sparse cuts.  SIAM Journal on Computing, 23/3, 1994,. 466-487. Preliminary version has appeared in the proceedings of the 22nd Annual ACM Symposium on the Theory of Computing (1990), 310-321.
• T. Leighton, F. Makedon, S. Plotkin, C. Stein, E. Tardos, S. Tragoudas: Fast Approximation Algorithms for Multicommodity Flow Problems, Journal of Computer and System Sciences, 50 (STOC'91 special issue), 1995, pp. 228--243. Preliminary version has appeared in the Proceedings of the 23rd Annual ACM Symposium on the Theory of Computing (1991), 101-110.
• S.A. Plotkin, D. Shmoys, and E. Tardos, Fast approximation algorithms for fractional packing and covering problems, to appear in Mathematics of Operations Research. ORIE TR-999.  Preliminary version has appeared in the Proceedings of the 32nd Annual IEEE Symposium on the Foundations of Computer Science (1991), 495-505.

Networks with transit times

• B. Hoppe and E. Tardos: Polynomial Time Algorithms for Some Evacuation Problems. In the proceeding of the 5th Annual ACM-SIAM Symposium on Discrete Algorithms, January 1994, pp. 433-441. .
• B. Hoppe and E. Tardos: The Quickest Transshipment Problem, journal version of the paper in the proceeding of the 6th Annual ACM-SIAM Symposium on Discrete Algorithms, 1995 pp. 512-521.
• L. Fleischer and E. Tardos. Efficient Continuous-Time Dynamic Network Flow Algorithms. Operations Research Letters 23 (1998) pp. 71-80.

Effective bandwidth

• J. Kleinberg, Y. Rabani and E. Tardos. Allocating Bandwidth for Bursty Connection. Journal version of the paper in the Proceedings of the 29th ACM Symposium on Theory of Computing, May, 1997, pp. 664-673.

Finding cuts in graphs

• S.A. Plotkin and E. Tardos, Improved Bounds on the Max-flow Min-cut Ratio for Multicommodity Flows. Combinatorica. Preliminary version has appeared in the Proceedings of the 25th Annual ACM Symposium on Theory of Computing, 1993, pp. 691-697.  
• P. Klein, S. Plotkin, S. Rao and E. Tardos: Approximation Algorithms for Steiner and Directed Multicuts. 
• Zoya Svitkina, and Eva Tardos. Min-Max Multiway Cut. Proceedings of APPROX 2004.

Separating cutting planes

• L. Fleischer and E. Tardos: Separating Maximally Violated Comb Inequalities in Planar Graphs, tech report version of the paper in the Proceedings of the 5th International Integer Programming and Combinatorial Optimization Conference (IPCO), June 1996, pp. 475-489.

Other Miscellaneous papers

• E. Tardos: The Gap Between Monotone and Non-Monotone Circuit Complexity is Exponential. Combinatorica, 1987, 7(4) 141-142.

Survey Papers

• Eva Tardos. Network Games. Proceedings of the Annual ACM Symposium on Theory of Computing, 2004.
• A. V. Goldberg,  E. Tardos, R. E. Tarjan: Network  Flow Algorithms, in   Paths, Flows and VLSI-Design (eds. B. Korte, L. Lovasz, H.J. Proemel, and A. Schrijver) Springer Verlag, 1990, 101-164.
• E. Tardos: Strongly Polynomial and Combinatorial Algorithms in Optimization, in the Proceedings of the International Congress of  Mathematicians Kyoto 1990, Springer-Verlag, Tokyo 1991, 1467-1478.
• D. B. Shmoys, E. Tardos: Computational Complexity, In the Handbook of Combinatorics (eds. R. Graham, M. Groetschel, and L. Lovasz) North Holland. An extended version has appeared as Technical Report 918, School of  Operations Research and Industrial Engineering, Cornell University.
• L. Lovasz, D. B. Shmoys and E. Tardos: Combinatorics in Computer Science,  In the Handbook of Combinatorics (eds. R. Graham, M. Groetschel,  and L. Lovasz) North Holland.
• E. Tardos: Approximate Min-Max Theorems and Fast Approximation Algorithms for Multicommodity Flow Problems, annotated bibliography.  In Proc. of the Summer School on Combinatorial Optimization, in Maastricht,
  The Netherlands, Aug. 1993.
• E. Tardos: Approximate Min-Max Theorems and Fast Approximation  Algorithms for Multicommodity Flow Problems, In Proc. Network Optimization  Theory and Practice (NETFLOW), in San Miniato (PI) Italy, Oct. 1993.