Workshop GPT&QIT
Generalized Probabilistic Theories and Quantum Information

Lyon, July 1st-2nd, 2019


  • Ludovico Lami (Nottingham) : an introduction to General Probabilistic Theories

    Abstract: This series of lectures aims to provide an introduction to general probabilistic theories (GPTs), with focus on the physical motivations behind it, the mathematical aspects of the formalism, and some of the most pressing outstanding problems. The mini-course is composed by four lectures of 1 1/2 hours each, structured as follows:

    Research talks

  • Andreas Bluhm (Munich) : A strengthened data processing inequality for the Belavkin-Staszewski relative entropy
    Abstract: see arXiv preprint

  • Anna Jenčová (Bratislava) : Incompatible measurements in GPT
    Abstract: General probabilistic theories provide a framework for studying incompatibility of measurements from a geometric point of view. In this talk, we concentrate on collections of two-outcome measurements, or effects.  We discuss characterizations of (in)compatible collections of measurements  and introduce the notion of an incompatibility witness.  We study some notions of incompatibility degree and show a geometric characterization of the maximal incompatibility degree of a collection of effects, attainable in a given theory.

  • Maria Jivulescu (Timisoara) : Random positive operator valued measures
    Abstract: We introduce several notions of random positive operator valued measures (POVMs), and we prove that some of them are equivalent. We then study statistical properties of the effect operators for the canonical examples, obtaining limiting eigenvalue distributions with the help of free probability theory. Similarly, we obtain the large system limit for several quantities of interest in quantum information theory, such as the sharpness, the noise content, and the probability range. Finally, we study different compatibility criteria, and we compare them for generic POVMs. Joint work with Teiko Heinosaari and I. Nechita, see arXiv preprint.

  • Alexander Müller-Hermes (Copenhagen) : Positivity of linear maps under tensor powers
    Abstract: Both completely positive and completely copositive maps stay positive under tensor powers, i.e., under tensoring the linear map with itself. But are there other examples of maps with this property? We discuss the connection of this question to the NPPT bound entanglement problem, and give a negative answer for maps on 2-dimensional systems. We will then consider more general questions for other classes of linear maps. In particular we will show that any decomposable map, that is neither completely positive nor completely copositive, will lose decomposability eventually after taking enough tensor powers. As an application this gives rise to new examples of non-decomposable positive maps.

  • Martin Plávala (Bratislava) : No-free-information principle in general probabilistic theories
    Abstract: In quantum theory, the no-information-without-disturbance and no-free-information principles express that those observables that do not disturb the measurement of another observable and those that can be measured jointly with any other observable must be trivial, i.e., coin tossing observables. We show that in the framework of general probabilistic theories these statements do not hold in general and continue to completely specify these two classes of observables. In this way, we obtain characterizations of the probabilistic theories where these statements hold. See arXiv preprint


    All talks take place in the Braconnier building, room 112 (1st floor). The building is just in front of the tramway stop "Université Lyon 1".


    Here is the schedule.


  • Simon Andreys (Lyon)
  • Guillaume Aubrun (Lyon)
  • Ivan Bardet (Cambridge)
  • Denis Bernard (Paris)
  • Andreas Bluhm (Munich)
  • Omar Fawzi (Lyon)
  • Anna Jencova (Bratislava)
  • Maria Jivulescu (Timisoara)
  • Ludovico Lami (Nottinhgam)
  • Alexander Müller-Hermes (Copenhagen)
  • Ion Nechita (Toulouse)
  • Martin Plavala (Bratislava)
  • Christoper Salinas Zavala (Saint-Étienne)
  • Jean-Marie Stéphan (Lyon)
  • Shang-Chun Yu (Lyon)

    If you would like to participate, please tell me: aubrun[AT]


    The workshop is funded by the ANR Grant Stoq