THURSDAY - APRIL 5                                     

8:30 am - 10:40 am - PLENARY 6   

(PL6)  Physics and Consciousness I

Lucien Hardy, Perimeter Institute for Theoretical Physics                  

Robert Alfano, City College of New York  

Christoph Simon, University of Calgary     


Lucien Hardy, PhD

Perimeter Institute for Theorectical Physics

Adjunct Faculty, Physics and Astronomy

University of Waterloo


Lucien Hardy received his PhD at Durham University in 1992 under the supervision of Professor Euan J Squires. He has held research and lecturing positions in various cities across Europe. While in Rome Lucien collaborated on an experiment to demonstrate quantum teleportation. In 1992 he found a very simple proof of non-locality in quantum theory which has become known as Hardy’s theorem.

Research Interests

I am working on operational approaches to Quantum Theory, General Relativity, and Quantum Gravity. Specifically I have developed an operational framework in which Quantum Theory and General Relativity can be formulated. Ultimately, I hope to formulate Quantum Gravity in this framework.

In 2001 I developed an operational probabilistic approach that provided the basis for a set of "reasonable axioms" from which the usual rules of Quantum Theory can be derived. In 2010 I further developed this framework as a diagrammatic calculus, the duotensor formalism, for general circuits. In 2011 I used this framework to provide a reformulation of Quantum Theory - the operator tensor formulation and, also, provided a new set of reasonable axioms from which Quantum Theory can be reconstructed.

The operator tensor reformulation motivated taking a look at the issue of composition in physics. Typically, when we study a physical object, we regard it as being built out of small objects joined together in a particular way. In 2013 I wrote a paper providing a more general theory for the use of composition in physics. Such ideas of composition may play a role across different fields in physics.

Most recently (2016), I have shown how to use ideas of composition to provide an operational reformulation of General Relativity. This requires, first of all, making an assertion as to what the directly observable quantities are. For this I nominate a set of scalar fields and consider point coincidences in their values. This provides an operational space (or op-space). We can consider regions of op-space and how to glue together solutions corresponding to such regions. This leads to a diagrammatic calculus of the same nature as that used in the operator tensor formulation of Quantum Theory. This operational reformulation of General Relativity naturally suggests approaches to solving the problem of Quantum Gravity.

I am also developing an operator tensor formulation of Quantum Field Theory. In this approach operators are associated with regions of space time. These operators must satisfy physicality conditions which guarantee that probabilities are between 0 and 1 and that signals cannot be communicated faster than light.

Finally I am interested in using humans choose the settings in a Bell experiment. In 2017 I wrote a paper proposing that we have one hundred humans at each end of a Bell experiment that is run over a distance of 100km. With other assumptions, this may be sufficient to ensure that a significant fraction of events have the setting decided by humans at each end.

Positions Held

  • 1997-2002 Royal Society University Research Fellow, University of Oxford
  • 1996-1997 Postdoctoral position at La Sapienza University, Rome, Italy.
  • 1994-1996 Lecturer in Mathematical Sciences Department, University of Durham, UK
  • 1993-1994 Royal Society postdoctoral fellow at the University of Innsbruck, Austria
  • 1992-1993 Lecturer in Mathematical Physics, Maynooth College, The National University of Ireland.