Current graduate students

Friday, November 19, 2010 3:30 pm - 4:30 pm EST (GMT -05:00)

David Jao: Constructing Elliptic Curve Isogenies in Quantum Subexponential Time

Given two elliptic curves over a finite field having the same cardinality and endomorphism ring, it is known that the curves admit an isogeny (a.k.a. algebraic map) between them, but finding such an isogeny is believed to be computationally difficult. The fastest known classical algorithm for this problem requires exponential time, and prior to our work no faster quantum algorithm was known. We show that this problem can be solved in subexponential time on a quantum computer, assuming the

Thursday, November 4, 2010 12:00 pm - 1:00 pm EDT (GMT -04:00)

Seth Lloyd: Sending a photon backwards in time

Seth Lloyd, Massachusetts Institute of Technology

Ever since Einstein, physicists have argued about whether time travel is consistent with the laws of physics, and, if so, how it might be accomplished. This talk presents a new theory of time travel based on quantum teleportation. Unlike previous theories, the theory can be tested experimentally. I report on an experimental realization of the 'grandfather paradox': we send a photon a few billionths of a second backwards in time and have it try to 'kill' its previous self.