6 papers
The Characterization of Noncontextuality in the Framework of Generalized Probabilistic Theories
David Schmid, John Selby, Elie Wolfe +2
To make precise the sense in which the operational predictions of quantum theory conflict with a classical worldview, it is necessary to articulate a notion of classicality within…
Compositional resource theories of coherence
John H. Selby, Ciarán M. Lee
Quantum coherence is one of the most important resources in quantum information. Indeed, preventing the loss of coherence is one of the most important technical challenges obstruct…
On the impossibility of coin-flipping in generalized probabilistic theories via discretizations of semi-infinite programs
Jamie Sikora, John H. Selby
Coin-flipping is a fundamental cryptographic task where a spatially separated Alice and Bob wish to generate a fair coin-flip over a communication channel. It is known that ideal c…
How to make unforgeable money in generalised probabilistic theories
John H. Selby, Jamie Sikora
We discuss the possibility of creating money that is physically impossible to counterfeit. Of course, "physically impossible" is dependent on the theory that is a faithful descript…
The time-reverse of any causal theory is eternal noise
Bob Coecke, Stefano Gogioso, John H. Selby
We consider a very general class of theories, process theories, which capture the underlying structure common to most theories of physics as we understand them today (be they estab…
Process-theoretic characterisation of the Hermitian adjoint
John Selby, Bob Coecke
We show that the physical principle "the adjoint associates to each state a `test' for that state" fully characterises the Hermitian adjoint for pure quantum theory, therefore prov…