Graphs, communication channels and nonlocality: the interplay

11.03.2015, 16:00 – 17:00

2015/03/11 16:00-17:00

Speaker: PhD Giannicola Scarpa | Location: Schlossgartenstraße 7 (S2|15), Handbibliothek IAP, Room 134, Darmstadt

Organizer: Nils Trautmann

Abstract

Certain graph parameters, like the independence number and the chromatic number, can be redefined as nonlocal games (a.k.a. Bell inequalities). When the players of the game are allowed to share entanglement, we obtain the notion of “quantum graph parameters”.

There are graphs for which such quantities exhibit a different behavior. Interestingly, this property is reflected in zero-error information theory, where noisy classical channels are studied through their confusability graphs. We will see an application of this idea.

But there is more: quantum graph parameters also help us in the study of nonlocality in general. We will see how every nonlocal game has a characteristic “game graph” and how different parameters provide information about the winning probability of quantum and classical strategies.

Short Bio

Giannicola Scarpa graduated from the University of Salerno in Computer Science in 2009. From 2009 to 2013 he was a PhD student at CWI, Amsterdam, the Netherlands, under the supervision of Ronald de Wolf. He received his PhD from University of Amsterdam in November 2013, defending a PhD thesis entitled “Quantum entanglement in non-local games, graph parameters and zero-error information theory”. Since January 2014, he is a post-doc in Andreas Winter's group at UAB in Barcelona, Spain.