2007/11/20 by Federico Piazza, Fabio Costa, Piazza, Federico +1 · 8 citations
Mathematics · Physics and Astronomy · #Black Holes and Theoretical Physics #Classical mechanics #Cosmology and Gravitation Theories #Entropy (arrow of time) #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Hamiltonian (control theory) #High Energy Physics - Theory (hep-th) #Locality #Mathematical physics #Mathematics #Minkowski space #Noncommutative and Quantum Gravity Theories #Physics #Quantum #Quantum Physics (quant-ph) #Quantum gravity #Quantum mechanics #Scalar field #Semiclassical physics #Theoretical physics #gr-qc #hep-th #quant-ph
paper · pdf · doi:10.48550/arxiv.0711.3048
published in arXiv (Cornell University) (Cornell University) · 10 pages
arxiv created 2007/11/20 · openalex publication_date 2007/11/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
As a novel approach with possible relevance to semiclassical gravity, we propose to define regions of space as quantum subsystems. After recalling how to divide a generic quantum system into ``parts'', we apply this idea to a free scalar field in Minkowski space and we compare two different localization schemes. The first scheme is the standard one, induced by the local relativistic fields; the alternative scheme that we consider is the one induced by the Newton-Wigner operators. If degrees of freedom are divided according to the latter, the Hamiltonian of the field exhibits a certain amount of non-locality. Moreover, when a region of space is cut off from the rest according to the Newton-Wigner scheme, the geometric entropy is finite and exhibits a sensible thermodynamic behaviour.