### DIMACS Theoretical Computer Science Seminar

Title: Quantum One-Way Communication can be Exponentially Stronger Than Classical Communication

Speaker: **Oded Regev**, Courant Institute, NYU

Date: Wednesday, April 17, 2013 11:00-12:00pm

Location: DIMACS Center, CoRE Bldg, Room 431, Rutgers University, Busch Campus, Piscataway, NJ

Abstract:

In STOC 1999, Raz presented a (partial) function for which there is a
quantum protocol communicating only $O(\log n)$ qubits, but for which
any classical (randomized, bounded-error) protocol requires $n^\eps$
bits of communication. That quantum protocol requires two rounds of
communication. Ever since Raz's paper it was open whether the same
exponential separation can be achieved with a quantum protocol that
uses only one round of communication. In other words, can quantum
one-way communication be exponentially stronger than classical two-way
communication? Here we settle this question in the affirmative.

The talk is entirely self-contained. In particular, there is no need
to be familiar with quantum communication (since it barely shows up in
our proof).

Based on joint work with Bo'az Klartag.

See: http://paul.rutgers.edu/~yixinxu/theory-spring13.html