Title: 

Coming full circle? A cyclic perspective on Kochen-Specker contextuality

Abstract:

Contextuality is a key distinguishing feature between classical and quantum physics. As a generalisation of nonlocality, it persistently fuels debates on quantum foundations. In turn, understood as a resource for quantum computation, it is expected to hold the key to quantum advantage. Yet, despite its long recognised importance in quantum foundations and, more recently, in quantum computation, the essence of contextuality remains elusive: many different mathematical frameworks exist, each addressing slightly different aspects of the phenomenon, yet leaving various questions open.

In this talk, I will advocate a framework for contextuality, which subsumes various existing notions and approaches. Within this framework, I will motivate and introduce a conceptually new tool, which offers a fresh perspective on contextuality and captures its essence geometrically. I will then draw a number of consequences from this idea. In particular, I will resolve the apparent discrepancy between the original notion of contextuality, as introduced by Kochen and Specker, and the modern notion captured by noncontextuality inequalities.