### Brief Biography

I was born in
Chandigarh,
India,
which is the new capital of two states,
Punjab
and
Haryana,
and was designed in the 1950's by the French architect, Le
Corbusier. I did the first twelve years of my schooling there. Being
the son of a Mathematics professor exposed me to the subject very
early, so studying
Computer Science
for my bachelor's degree was a logical choice. I studied
at the
Indian Institute of Technology,
Kanpur ,
and graduated from there in 1989.
After my graduation I wanted to do a Ph.D. in Mathematics, but my
father convinced me to stick to Computer Science (sound
advice in hindsight!). So I started graduate school at the
Computer Science Department
at
Stanford University ,
and worked in the
Theory Division
with Professor
Vaughan Pratt.
I worked on algebraic models for concurrent computation,
in the style of Petri Nets, CCS and Event Structures, and eventually
came up with my model called
Chu Spaces. Chu
Spaces, or gates, can be used to model network behavior, and subsume
the behaviors describable by Petri Nets, CCS and CSP. They are simple
and asynchronous, and possess an elegant process algebra and a formal
verification system based on linear logic.
They also provide a translation between imperative and declarative
programs.

In spring 1993 Prof. Pratt recommended me to Vijay Saraswat at
Xerox
PARC, and I worked here for the
summer, laying the foundations of integrating Concurrent Constraint
Languages with Reactive Systems. I graduated from Stanford in 1994,
and joined PARC to work on a
NASA project for
modeling
electromechanical systems.
In September 1997 I moved to the
NASA Ames Research Center, to
work at the Autonomous Systems Group on using hybrid modeling and
analysis for building model-based
autonomous systems.

In January 2000 I joined
Stratify Inc.
(then PurpleYogi Inc.) as a member of the research staff. I
worked on a variety
of topics there, including document classification, document analysis,
and multilingual classification, among others. In March 2003, I joined Google Inc., and have been working on Search Quality. I also continue to
work on the modeling and analysis of probabilistic and hybrid systems.