5 papers
A Theory of Backgrounds and Background Independence
Marc Klinger
In this note, we describe how the study of backgrounds for general quantum systems can be formulated in terms of the representation theory of abstract algebras. We illustrate…
Generalized Entropy is von Neumann Entropy II: The complete symmetry group and edge modes
Marc S. Klinger, Jonah Kudler-Flam, Gautam Satishchandran
We consider the algebra of observables of perturbative quantum gravity in the exterior of a stationary black hole or the static patch of de Sitter spacetime. It was previously argu…
The Problem of Time and its Quantum Resolution
Marc S. Klinger, Robert G. Leigh
In this essay, we argue that the problem of time should not be regarded as an issue to be resolved within the prevailing framework for studying quantum gravity, but rather as an in…
Extensions from within
Shadi Ali Ahmad, Marc S. Klinger
Inclusions and extensions lie at the heart of physics and mathematics. The most relevant kind of inclusion in quantum systems is that of a von Neumann subalgebra, which is the focu…
Emergent Geometry from Quantum Probability
Shadi Ali Ahmad, Marc S. Klinger
Carrying the insights of conditional probability to the quantum realm is notoriously difficult due to the non-commutative nature of quantum observables. Nevertheless, conditional e…