Matilde - Bounding the asymptotic quantum value of all multipartite compiled nonlocal games

Fri, 30 May 2025 00:00:00 +0000

Bounding the asymptotic quantum value of all multipartite

compiled nonlocal games This seminar, given by Matilde, will happend on 30 May 2025, at 14:0. It will take place in Room Not specified.

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Abstract

Nonlocal games are a powerful tools to distinguish between correlations possible in classical and quantum worlds. Kalai et al. (STOC'23) proposed a compiler that converts multipartite nonlocal games into interactive protocols with a single prover, relying on cryptographic tools to remove the assumption of physical separation of the players. While quantum completeness and classical soundness of the construction have been established for all multipartite games, quantum soundness is known only in the special case of bipartite games.

We prove that Kalai’s compiler indeed achieves quantum soundness for all multipartite compiled nonlocal games, by showing that any correlations that can be generated in the asymptotic case correspond to quantum commuting strategies.

Our proof uses techniques from the theory of operator algebras, and relies on a characterisation of sequential operationally no-signalling strategies as quantum commuting operator strategies in the multipartite case, thereby generalising several previous results. On the way, we prove a new chain rule for Radon-Nikodym derivatives of completely positive maps on $C^\ast$-algebras which may be of independent interest.

Matilde | LIP6 - QI Team

Matilde - Bounding the asymptotic quantum value of all multipartite compiled nonlocal games

Bounding the asymptotic quantum value of all multipartite

Abstract