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Conferences, Lectures, & Seminars
Events for July
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CSI PhD Defense - Symmetry in Quantum Walks
Mon, Jul 02, 2007 @ 11:00 AM - 12:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
SPEAKER: Mr. Hari Krovi, Communication Sciences InstituteABSTRACT: A quantum walk on a graph (analogue of a classical random walk) is an application of a unitary evolution operator on a Hilbert space which corresponds to the graph. Hitting time of a quantum walk is the average time it takes to go from a designated initial vertex to a designated final vertex. Symmetries of the graph, given by its automorphism group, can be inherited by the evolution operator. Symmetry can cause the hitting time for certain initial states of a quantum walk to be infinite, in contrast to a classical random walk. We give a sufficient condition for a quantum walk to have infinite hitting times. Using the irreducible representations of the automorphism group, we derive conditions under which quantum walks defined on graphs have infinite hitting times for some initial states. Another aspect of symmetry is fast hitting times. It has been shown in the literature that a quantum walk on some graphs such as the hypercube has an exponentially faster hitting time than a classical walk. We show that this is because the walk is confined to a subspace of the total Hilbert space due to symmetry inherited from the graph. We show that a quantum walk confined to the subspace corresponding to this symmetry group can be seen as a different quantum walk on a smaller "quotient" graph. The automorphisms of the quotient graph which are inherited from the original graph are the original automorphism group modulo the subgroup H used to construct it. Thus the quotient graph is constructed by removing the symmetries of the subgroup H from the original graph. Such a reduction to a smaller graph may be useful in algorithms based on quantum walks.Advisor: Prof. Todd Brun, tbrun@usc.edu
Location: Hughes Aircraft Electrical Engineering Center (EEB) - 500
Audiences: Everyone Is Invited
Contact: Mayumi Thrasher
This event is open to all eligible individuals. USC Viterbi operates all of its activities consistent with the University's Notice of Non-Discrimination. Eligibility is not determined based on race, sex, ethnicity, sexual orientation, or any other prohibited factor. -
Service Research in IBMs India Lab
Fri, Jul 13, 2007 @ 10:30 AM - 11:30 AM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Abstract:
In recent years, IBM has invested heavily in its services business in India. IBM's India Research Lab has also placed significant focus on the technical problems that need to be solved to improve and differentiate these services-based operations. The solutions to these problems draw from various computer science disciplines like distributed systems, software engineering, information management, and optimization. In this talk, I will give an overview of the services research landscape in IBM India, present some representative problems and solutions, and discuss our new academic initiatives in "Service Science".Bio:
Dr. Guruduth Banavar is the Associate Director of IBM's India Research Laboratory, Bangalore, and also heads the Services Innovation and Research Center (SIRC). He started IBM's new research group in Bangalore, where a world-class team is now focused on cutting-edge industrial research problems relevant to the region and globally. Previously, Guru was the Senior Manager of the Pervasive Infrastructure Department at IBM's Thomas J. Watson Research Center in New York, where he led a large research team working on several aspects of pervasive computing. He has also developed technology innovations in areas like synchronous collaboration, content-based publish-subscribe systems, middleware for content delivery, and platform-independent application development. See http://www.research.ibm.com/people/b/banavar for more details.
Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Annie Yu
This event is open to all eligible individuals. USC Viterbi operates all of its activities consistent with the University's Notice of Non-Discrimination. Eligibility is not determined based on race, sex, ethnicity, sexual orientation, or any other prohibited factor. -
Optimal Quantum Data Compression with Side Information at the Sender and Receiver
Mon, Jul 16, 2007 @ 11:00 AM - 12:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
SPEAKER: Dr. Jon Yard, CaltechAbstract: Information theory - as introduced by Shannon almost 60 years ago - studies the asymptotic limits for the processing of statistically modeled information in such problems as data compression and coding for noisy channels. In recent years, a rich generalization of Shannon's theory has emerged which incorporates distinctly quantum mechanical resources such as qubits (quantum bits), entangled quantum states, and quantum channels. In this talk, I will present the optimal solution to a general quantum data compression problem where the sender and receiver each have quantum side information. The corresponding optimal protocol - quantum state redistribution - provides the first known operational interpretation to quantum conditional mutual information. The optimal rates satisfy certain elegant and intuitive properties, while admitting a general "thermodynamical" organizing principle that I will recall. I will conclude by sketching an existence proof for the optimal protocol, while showing how state redistribution generalizes and organizes a number of recent results in quantum information theory such as the celebrated fully quantum reverse Shannon and fully quantum Slepian-Wolf protocols.Bio Jon Yard received his Ph.D. from the Information theory group of Tom Cover at Stanford University in 2005. Since then, he has been a postdoc with Patrick Hayden at McGill University and also with the Institute for Quantum Information at Caltech. This summer, he will begin a postdoc with the Quantum Institute at Los Alamos National Laboratories.Host: Prof. Todd Brun, tbrun@usc.edu
Location: Frank R. Seaver Science Center (SSC) - 319
Audiences: Everyone Is Invited
Contact: Mayumi Thrasher
This event is open to all eligible individuals. USC Viterbi operates all of its activities consistent with the University's Notice of Non-Discrimination. Eligibility is not determined based on race, sex, ethnicity, sexual orientation, or any other prohibited factor.
