5 papers
On the relation between perspective-neutral, algebraic, and effective quantum reference frames
Julian De Vuyst, Philipp A. Hoehn, Artur Tsobanjan
The framework of internal quantum reference frames (QRFs) constitutes a universal toolset for dealing with symmetries in quantum theory and has led to new revelations in quantum gr…
Crossed products and quantum reference frames: on the observer-dependence of gravitational entropy
Julian De Vuyst, Stefan Eccles, Philipp A. Hoehn +1
A significant step towards a rigorous understanding of perturbative gravitational entropy was recently achieved by a series of works showing that a proper accounting of gauge invar…
Linearization (in)stabilities and crossed products
Julian De Vuyst, Stefan Eccles, Philipp A. Hoehn +1
Modular crossed product algebras have recently assumed an important role in perturbative quantum gravity as they lead to an intrinsic regularization of entanglement entropies by in…
Gravitational entropy is observer-dependent
Julian De Vuyst, Stefan Eccles, Philipp A. Hoehn +1
In quantum gravity, it has been argued that a proper accounting of the role played by an observer promotes the von Neumann algebra of observables in a given spacetime subregion fro…
A Natural Introduction to Fine-Tuning
Julian De Vuyst
A well-known topic within the philosophy of physics is the problem of fine-tuning: the fact that the universal constants seem to take non-arbitrary values in order for live to thri…