Observers in Quantum and Foil Theories

Conference Date: 
Monday, April 2, 2018 (All day) to Friday, April 6, 2018 (All day)
Scientific Areas: 
Quantum Foundations


Foil theories, sometimes called mathematically rigorous science fiction, describe ways the world could have been were it not quantum mechanical. Our understanding of quantum theory has been deepened by contrasting it with these alternatives. So far, observers in foil theories have only been modeled implicitly, for example via the recorded probabilities of observing events. Even when multi-agent settings are considered, these agents tend to be compatible in the classical sense that they could always compare their observations. Scenarios where agents and their memories are themselves modeled as physical systems within the theory (and could in particular measure each other, as in Wigner's friend experiment) have not yet been considered. In this workshop, we will investigate which foil theories allow for the existence of explicit observers, and whether they allow for paradoxes in multi-agent settings such as those found in quantum theory. We will also investigate which interpretations of quantum theory would equally well interpret the foil theories, and which interpretations are truly quantum. We will gain a deeper understanding of how this can happen by discussing appropriate definitions observers in these theories and seeing how such observers learn about their environment.

  • Stephen Bartlett, University of Sydney
  • Thomas Galley, University College London
  • Markus Mueller, Perimeter Institute & Institute for Quantum Optics and Quantum Information, Vienna
  • Nuriya Nurgalieva, ETH Zurich
  • Jess Riedel, Perimeter Institute
  • Nitica Sakharwade, Perimeter Institute
  • Carlo Maria Scandolo, University of Oxford
  • Rudiger Schack, Royal Holloway University of London
  • David Schmid, Perimeter Institute
  • Rob Spekkens, Perimeter Institute
  • Joel Wallman, University of Waterloo

Scientific Organizers:

  • Lidia del Rio, ETH Zurich
  • Matthew Pusey, University of Oxford
  • Ana Belen Sainz, Perimeter Institute