Group action in topos quantum physics

Topos Theoretic Quantum Realism

Topos Quantum Theory (TQT) is standardly portrayed as a kind of ‘neo-realist’ reformulation of quantum mechanics. In this paper, we study the extent to which TQT can really be characterised as a realist formulation of the theory, and examine the question of whether the kind of realism that is provided by TQT satisfies the philosophical motivations that are usually associated with the search for...

Laser physics: Quantum controversy in action

Topos logic in measurement-based quantum computation

We report first steps towards elucidating the relationship between contextuality, measurementbased quantum computation (MBQC) and the non-classical logic of a topos associated with the computation. We show that, in a class of MBQC, classical universality requires non-classical logic, which is ‘consumed’ during the course of the computation, thereby pinpointing another potential quantum computat...

Quantum Physics: A Case for Anti-Realism?

Group representation theory and quantum physics∗

This is a basic tutorial on the use of group representation theory in quantum physics, in particular for such systems as molecules and crystals, which forms the basis of spectroscopic studies in physics and chemistry. Note that, despite the now venerable character of the aforementioned scientific endeavors, group representation theory still finds interesting and novel applications, such as the ...