May 2014 - philphysmunich

Quantum Information Theory Reading Group at LMU
by Michael Cuffaro July 13, 2014

July 13, 2014

Dear all, the Summer 2014 reading group on Quantum Information Theory will begin this coming Monday, April 14th, from 18:00 - 20:00 (CT). After that we will meet bi-weekly. The location is Ludwigstraße 31, Room 021. The first part of the meeting on Monday will be devoted to organisational matters and to discussing subsequent meeting topics. During the second part of the meeting, *Seamus Bradley* will introduce us to *Classical Information Theory*. As background reading, you may want to look at Parts I and II of Claude Shannon's "A Mathematical Theory of Communication" (1948). It can be downloaded from: http://cm.bell-labs.com/cm/ms/what/shannonday/shannon1948.pdf Everyone interested in the topic of quantum information theory is encouraged to attend the group. Please also feel free to distribute this to anyone not subscribed to this mailing list who you think may be interested in attending. If you are receiving this email twice because you belong to this mailing list but are explicitly included in the Cc list, please let me know and I will remove you from the latter. I hope to see many of you next week. Best wishes, -- Michael Cuffaro Postdoctoral Fellow Ludwig-Maximilians-Universität München Fakultät für Philosophie, Wissenschaftstheorie und Religionswissenschaft Lehrstuhl für Wissenschaftstheorie Munich Center for Mathematical Philosophy Geschwister-Scholl-Platz 1 80539 München, Deutschland http://www.michaelcuffaro.com

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Talk by Tom Pashby at MCMP (May 28)
by Dardashti, Radin May 25, 2014

May 25, 2014

Speaker: Tom Pashby (Pittsburgh) Wednesday 28th May 2014 Location: Ludwigstr. 31 room 021 Time: 16:15 - 17:45 Title: Against Dogma: Locality, Conditionalisation, and Collapse in Relativistic Quantum Mechanics Abstract: I argue here against the widespread view (due to David Malament) that the non-commutativity of non-instantaneous localisation projections implies the existence of act-outcome correlations in relativistic QM. There are two facets to my argument: first, I claim that the interpretation of collapse as a process brought about by the experimenter is mistaken; second, I contend that a fully relativistic model should not condition on the occurrence of spacelike separated instantaneous events. This leaves the door open to define a relativistically invariant (but non-commuting) system of localization, which I interpret in terms of conditional probabilities for the occurrence of events. In accord with Tumulka (2009), I conclude that non-local correlations of events in a relativistic quantum theory need not imply the sort of action at a distance that worries Malament (1996).

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Talk by Adam Caulton (Cambridge)
by Karim Thébault May 15, 2014

May 15, 2014

Speaker: Adam Caulton (Cambridge) Wednesday 21st May 2014 Location: Ludwigstr. 31 room 021 Time: 16:15 - 17:45 Title: Adventures off the mass-shell What is the correct possibility space for a given particle of a quantum field? The firm orthodoxy, initiated by Wigner in 1939, is that we should look to the irreducible representations of the Poincaré group. But the justifications for this are murky, so I offer two rational reconstructions. According to one, the justification is that the Poincaré group comprises all the actions that can be performed on a simple system; but this is false, made particularly relevant in the case of interactions. According to another, conflicting reconstruction, Poincaré invariance is a reality condition; but this applies only to the entire system of fields, not to individual particles. Therefore it ought not constrain the possibility spaces of individual particles. Consequently, I argue, we have reason to consider "larger" state spaces than are normally considered. On one such approach, which I will advocate, the elements of these state spaces represent entire four-dimensional histories rather than instantaneous states---most of which are "off mass-shell", in that the relativistic mass condition is violated. I conclude by arguing that off-mass-shell particles, far from being mere formal inventions for the sake of S-matrix calculations, are just as "real" as their free counterparts---indeed, they are to be found as much in classical relativistic theories as in quantum relativistic theories. _______________________________________________ philphysmunich mailing list philphysmunich(a)lists.lrz.de https://lists.lrz.de/mailman/listinfo/philphysmunich

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