Speaker: Guido Bacciagaluppi (Aberdeen) Date: Tue., April 14 Location: Geschwister-Scholl-Platz 1, E210 Time: 16:00 - 18:00 Title: The Misleading Equivalence of Decoherence and Branching Abstract: Well-known theorems relating decoherence and branching suggest using the time-arrow of decoherence to explain the macroscopic branching structure of the Everettian multiverse. It is argued by general considerations and in a toy model that branching can be explained naturally also in the case of time-symmetric decoherence as a purely perspectival effect of coarse-graining over 'records' of future events. This result may impinge on the discussion of identity, uncertainty and probability in Everett. ------------------------------------------------------------------------------------- Speaker: Guido Bacciagaluppi (Aberdeen) Date: Thu., April 16 Location: Hans-Kopfermann-Str. 1, Campus Garching, MPQ, seminar room B2.46 Time: 14:00 - 15:00 Title: Leggett–Garg Inequalities, Pilot Waves and Contextuality Abstract: In this talk we first analyse Leggett and Garg's argument to the effect that macroscopic realism contradicts quantum mechanics. After making explicit all the assumptions in Leggett and Garg's reasoning, we argue against the plausibility of their auxiliary assumption of non-invasive measurability, using Bell's construction of stochastic pilot-wave theories as a counterexample. Violations of the Leggett–Garg inequality thus do not provide a good argument against macrorealism per se. We then apply Dzhafarov and Kujala's analysis of contextuality in the presence of signalling to the case of the Leggett–Garg inequalities, with rather surprising results. An analogy with pilot-wave theory again helps to clarify the situation. ------------------------------------------------------------------------------------- Speaker: Guido Bacciagaluppi (Aberdeen) Date: Fri., April 17 Location: Hans-Kopfermann-Str. 1, Campus Garching, MPQ, seminar room B0.22 Time: 10:15 - 11:45 Title: Did Bohr Understand EPR? Abstract: Contrary to widespread belief, I argue that Niels Bohr's arguments in his reply to Einstein Podolsky and Rosen in 1935 take fully into account the separation between the two particles. Specifically, I argue that there is no sleight of hand in the passage from Bohr's discussion of a single particle passing through a slit and his subsequent discussion of the EPR example. ------------------------------------------------------------------------------------- Speaker: David Wallace (Oxford) Date: Wed., April 15 Location: Ludwigstr. 31, ground floor, room 021 Time: 16:15 - 17:45 Title: Statistical mechanics from an emergentist viewpoint Abstract: I sketch a view of the philosophy of statistical mechanics as (a) concerned primarily with the interrelations between different dynamical systems describing more or less coarse-grained degrees of freedom of a system, and only secondarily with thermodynamic notions like equilibrium and entropy, and (b) informed by developments in contemporary mainstream physics. I develop, as concrete examples, (i) the projection-based approach to kinetic equations developed in the 1970s by Balescu, Prigogine, Zwanzig et al, and (ii) the relevance of quantum mechanics to nominally “classical” systems like the ideal gas. ------------------------------------------------------------------------------------- Speaker: Andrea Oldofredi (Lausanne) Date: Thu., April 16 Location: Ludwigstr. 31, ground floor, room 021 Time: 12:15 - 13:45 Title: Extensions of Bohmian Mechanics to Quantum Field Theory (WIP Talk) Abstract: The aim of this talk is twofold: firstly I will show the extensions of Bohmian Mechanics (BM) to Quantum Field Theory (QFT) pointing out virtues and limits of these models, and secondly I will discuss whether or not they are interesting alternatives to the conventional QFT. Since it is widely believed that BM cannot be extended to the realm of QFT in virtue of several no go theorems that exclude the possibility to have a particle ontology in relativistic quantum mechanics, I will show how this criticism misses the point. The severe problems that BM encounters within the relativistic framework are discussed as well. Finally, I will point out the necessity to have a clear ontology as a basic ingredient of a physical theory.