Category Archives: Uncategorized

Ruetsche talk posted

With apologies for the delay, we have now posted Laura Ruetsche’s talk from the spring. Find it above under speakers, or on our YouTube channel here: Renormalization Group Realism: An Unduly Skeptical Review


Speaker at UIC on November 15th

On Wednesday 15 November 2017 at UIC (11.15am local time), Laurent Freidel (Perimeter) will speak on The Geometry of Relative Locality.

Abstract: In this talk I will describe the fundamental tension that forbids us in my view to reconcile gravity with the quantum. I will explain how this tension forces us to profoundly revise the concept of locality  and that this can be done by letting go of the hypothesis of Absolute locality. I will formulate what relaxing this hypothesis means and will describe our attempts to flesh out the concept of  relative locality. I will also  exemplify what relative locality is into specific examples. In particular, we will show how these ideas allows us to natural interpret geometrically the T-duality symmetry of string theory. This symmetry will be seen as relativistic change of frame in a  modular space, a notion of space that replaces Minkowski for quantum geometry. I will also show how the geometry of relative locality is intimately linked with generalized geometry and the geometry of quantum mechanics via a natural structure on phase space called Born geometry. Finally, and if time permits, I will comment how relative locality can shade a bright new light on the problem of unification. This talks involves several new important concepts: relative locality, generalized geometry, modular space, Born geometry. I will try to present them in a non technical manner as much as possible. In terms of technical difficulty, this talk rates 4/5 4

Full details above on the speakers page.

Call for Applications: Junior Visiting Fellowship to visit Geneva

Call for Applications:
University of Geneva

The philosophy of physics group at the Department of Philosophy in Geneva (the Geneva Symmetry Group) solicits applications for short- to medium-term junior visiting fellowships for advanced PhD students and recent PhDs, to visit the group anytime between now and June 2018. The fellowships are funded by the John Templeton Foundation grant ‘Space and Time after Quantum Gravity’.

Continue reading Call for Applications: Junior Visiting Fellowship to visit Geneva

Wallace to speak at UIC

On Wednesday 18 October 2017 please join us at UIC (or at Geneva via livestream, or on our YouTube channel) to hear David Wallace (USC) speaking on “The Case for Black Hole Thermodynamics”

Abstract: I give a fairly systematic and thorough presentation of the case for regarding black holes as thermodynamic systems in the fullest sense (contra recent work by Dougherty and Callender), with particular attention to (i) the availability in classical black hole thermodynamics of a well-defined notion of adiabatic intervention; (ii) the power of the membrane paradigm to make black hole thermodynamics precise and to extend it to local-equilibrium contexts; (iii) the central role of Hawking radiation in permitting black holes to be in thermal contact with one another; (iv) the wide range of routes by which Hawking radiation can be derived and its back-reaction on the black hole calculated; (v) the interpretation of Hawking radiation close to the black hole as a gravitationally bound thermal atmosphere.

More information on all talks above.

First talk of the year!

• Wednesday 27 September 2017 at Geneva – Alexei Grinbaum (CEA-Saclay/LARSIM): How device-independent approaches change the meaning of physical theory

Abstract: Dirac sought an interpretation of mathematical formalism in terms of physical entities and Einstein insisted that physics should describe “the real states of the real systems”. While Bell inequalities put into question the reality of states, modern device-independent approaches do away with the idea of entities: physical theory may contain no physical systems. Focusing on the correlations between operationally defined inputs and outputs, device-independent methods promote a view more distant from the conventional one than Einstein’s `principle theories’ were from `constructive theories’. On the examples of indefinite causal orders and almost quantum correlations, we ask a puzzling question: if physical theory is not about systems, then what is it about? Device-independent models suggest that physical theory can be `about’ languages. This answer indicates a direction for moving beyond quantum theory. In terms of technical difficulty, this talk rates 4/5 4