Time, Change, Observables, and Quantum Gravity
A special issue of Entropy (ISSN 1099-4300). This special issue belongs to the section "Time".
Deadline for manuscript submissions: 30 May 2025 | Viewed by 120
Special Issue Editor
Special Issue Information
Dear Colleagues,
While change is evident in daily life and classical physics, change has seemed to be missing in canonical quantum gravity, from which change in daily life and classical physics presumably ought to emerge somehow. Part of the issue is the gauge (coordinate or diffeomorphism) freedom of General Relativity, which is external, distinguishing it from that of electromagnetism and even Yang–Mills theories. Recent decades have seen a variety of arguments, calculations, definitions, etc., aiming to resolve the puzzle of missing change in canonical quantum gravity. Perhaps canonical gravity needs a distinctive treatment of the Hamiltonian constraint, or a manifestly Lagrangian equivalent classical basis and associated redefinition of observables, or a new way to impose constraints, or a distinctive treatment for the Hamiltonian constraint. Is change missing already in classical canonical gravity, or is the classical problem largely verbal and the real problem quantum mechanical? If the quantum problem is more clearly genuine, does it have a principled solution? Why do ways of treating constraints that seem arguable classically appear perhaps inevitable quantum mechanically? To what degree can stipulative definitions and postulations be avoided in favour of calculations and reflective equilibrium? Papers addressing issues on this topic are invited for this Special Issue.
Dr. J. Brian Pitts
Guest Editor
Manuscript Submission Information
Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.
Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Entropy is an international peer-reviewed open access monthly journal published by MDPI.
Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.
Keywords
- change
- observables
- constrained Hamiltonian dynamics
- gauge freedom
- quantum gravity
Benefits of Publishing in a Special Issue
- Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
- Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
- Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
- External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
- e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.
Further information on MDPI's Special Issue polices can be found here.