Dr. Raga Gopalakrishnan

Computing and Mathematical Sciences, California Institute of Technology

Research Groups: Rigorous Systems Research Group (RSRG) and Social and Information Sciences Laboratory (SISL)

Email: ragad3 [at] caltech [dot] edu

Address: 1200 E California Blvd MC 305-16, Pasadena, CA 91125.

Phone: (626) 395-3556

About me

I just recently graduated from California Institute of Technology with my PhD! I will move to CU-Boulder in August to pursue postdoctoral research. My advisor at Caltech was Dr. Adam Wierman, and I was affiliated with two research groups - Rigorous Systems Research Group (RSRG) and Social and Information Sciences Laboratory (SISL). Prior to joining Caltech, I obtained my Bachelors degree in Computer Science from Indian Institute of Technology Madras. You can find my CV here.

Research summary

My research interests lie in the domain of applied algorithmic game theory (AGT). Traditional applications of AGT have been in the field of auction theory and mechanism design. However, my recent focus has been on research problems in AGT that are motivated by somewhat non-traditional applications, such as distributed control, and heterogeneous multi-server queueing systems:

COST SHARING GAMES studies a fundamental question - how should the cost incurred (or revenue generated) by a set of self-interested agents be shared among them? The design of desirable (stable/fair and efficient) cost sharing rules traditionally forms a building block of optimal mechanism design. But beyond that, it also has a direct application in game theoretic control, a promising new approach for optimal resource allocation in computer systems, where distributed control problems are modeled in a game theoretic framework by designing utility functions for agents, and the equilibria of the resulting game are viewed as stable operating points for the distributed system. My work aims to understand what cost sharing rules guarantee a pure Nash equilibrium for a broad class of games, and which among these are most efficient, in terms of price of anarchy/stability.

Potential games are necessary to ensure pure Nash equilibria in cost sharing games.
with Jason R. Marden and Adam Wierman. Submitted for journal publication.
[PDF] [Related publication]
SCHEDULING GAMES is concerned with the design of optimal scheduling policies for multi-server queueing systems, in a strategic environment. Traditional work in this area considers strategic arrivals and strategic pricing of service, but ignores strategic behavior among the servers, e.g., in service systems, where employees could react to the scheduling policy by strategically choosing their service rates in order to maximize their utility. The focus of my work is to study the effects of strategic behavior of heterogeneous servers on optimal system design.

Dispatching to incentivize fast service in distributed multi-server systems.
with Sherwin Doroudi, Amy R. Ward, and Adam Wierman. Working paper.
[PDF] [Related publication]

My detailed research statement can be found here.

PhD Thesis and Defense

My thesis was exclusively on cost sharing games. For more information and to download a copy, you can visit CaltechTHESIS.
[Slides] [Video]

Other papers

Fairness & efficiency in network performance isolation.
with Mohammad Alizadeh Attar, Vimalkumar Jeyakumar, Srinivas Narayana, and Balaji Prabhakar. Working paper.
[PDF]

Randomness and uncertainty in portfolio methods for inventory allocation in online advertising.
with Eric Bax, Krishna Prasad Chitrapura, and Sachin Garg. Working paper.
[PDF]
Note: These results were presented during RSRG and SISL seminars at Caltech. [Slides] [Video]

Foundations of group key management: Framework, security model and a generic construction.
with Naga Naresh Karuturi, C. Pandu Rangan, and Rahul Srinivasan. UNPUBLISHED MANUSCRIPT.
[PDF]

Recent publications

Potential games are necessary to ensure pure Nash equilibria in cost sharing games.
with Jason R. Marden and Adam Wierman. EC 2013.
[PDF] [Full Version]

Cache me if you can: Capacitated selfish replication in networks.
with Dimitrios Kanoulas, Naga Naresh Karuturi, C. Pandu Rangan, Rajmohan Rajaraman, and Ravi Sundaram. LATIN 2012.
[PDF] [Slides] [Full Version]

Characterizing distribution rules for cost sharing games.
with Jason R. Marden and Adam Wierman. NetGCOOP 2011.
[PDF] [Slides]
Note: A related poster was presented at SoCal NEGT 2011. [PDF]
Note: A full journal version with extended results is under preparation. A teaser poster was presented at the Summer School on Algorithmic Economics 2012. [PDF]

Dispatching to incentivize fast service in multi-server queues.
with Sherwin Doroudi and Adam Wierman. MAMA 2011.
[PDF] [Slides]
Note: These results were also presented during a SISL seminar at Caltech, and as part of an invited session at INFORMS APS 2011. [Slides]
Note: A related poster was presented at SoCal NEGT 2010. [PDF]
Note: A full journal version with extended results is under preparation.

An architectural view of game theoretic control.
with Jason R. Marden and Adam Wierman. HotMetrics 2010.
[PDF] [Slides]
Note: A poster with preliminary ideas was presented at the 9th Lee Center Workshop on Advanced Networking 2009 and also at SoCal NEGT 2009. [PDF]

On the provable security of multi-receiver signcryption schemes.
with Naga Naresh Karuturi, C. Pandu Rangan, S. Sharmila Deva Selvi, and S. Sree Vivek. ICISC 2009.
[PDF]

Cryptanalysis of Bohio et al.'s ID-based broadcast signcryption (IBBSC) scheme for wireless ad-hoc networks.
with Naga Naresh Karuturi, C. Pandu Rangan, S. Sharmila Deva Selvi, and S. Sree Vivek. PST 2008.
[PDF]

Cryptanalysis of Mu et al.'s and Li et al.'s schemes and a provably secure ID-based broadcast signcryption (IBBSC) scheme.
with Naga Naresh Karuturi, C. Pandu Rangan, S. Sharmila Deva Selvi, and S. Sree Vivek. WISA 2008.
[SpringerLink]

Teaching

I was a teaching assitant for CS/EE 144 - Ideas behind the Web (Winter 2011 and Winter 2012) and CS/EE 147 - Network performance analysis (Spring 2010).

My older website
This is also me