Bamonti, Nicola (2023) What is a reference frame in General Relativity? [Preprint]
 | There is a more recent version of this item available. |
|
Text
Bamonti-RF_CS.pdf Download (1MB) | Preview |
Abstract
In General Relativity, the terms ‘reference frame’ and ‘coordinate system’ must be distinguished. The former refers to physical systems that are dynamically coupled with the gravitational field, aside from possible approximations, while the latter refers to a set of mathematical variables that are representative artefacts. This necessary distinction is lost in pre-general relativistic physics, where we can choose as a reference frame a system of real physical objects that is not affected and cannot affect the physical system under consideration. Therefore, we can make it coincide with a coordinate system without the need for approximations. We propose a a novel three-fold distinction between three types of reference frames, considered as material systems. In particular, we discern between Idealised Reference Frames, Dynamical Reference Frames and Real Reference Frames, depending on their increasing physical role in the total dynamics. Using a Bianchi I model in Minisuperspace, we give a cosmological example of the use of a gravitational Dynamical Reference Frame, namely a reference frame constructed with gravitational degrees of freedom in the standard case where the gravitational stress-energy tensor is not defined in the Einstein field equations. We also analyse the role of active and passive diffeomorphisms in changing a reference frame.
| Export/Citation: | EndNote | BibTeX | Dublin Core | ASCII/Text Citation (Chicago) | HTML Citation | OpenURL |
| Social Networking: |
| Item Type: | Preprint | ||||||
|---|---|---|---|---|---|---|---|
| Creators: |
|
||||||
| Keywords: | reference frame, coordinate system, relational observables, Bianchi models, General Relativity, minisuperspace | ||||||
| Subjects: | Specific Sciences > Physics > Cosmology General Issues > Models and Idealization Specific Sciences > Physics Specific Sciences > Physics > Relativity Theory |
||||||
| Depositing User: | Mr Nicola Bamonti | ||||||
| Date Deposited: | 18 Jul 2023 14:43 | ||||||
| Last Modified: | 18 Jul 2023 14:43 | ||||||
| Item ID: | 22300 | ||||||
| Subjects: | Specific Sciences > Physics > Cosmology General Issues > Models and Idealization Specific Sciences > Physics Specific Sciences > Physics > Relativity Theory |
||||||
| Date: | 2023 | ||||||
| URI: | https://philsci-archive.pitt.edu/id/eprint/22300 |
Available Versions of this Item
- What is a reference frame in General Relativity? (deposited 18 Jul 2023 14:43) [Currently Displayed]
Monthly Views for the past 3 years
Monthly Downloads for the past 3 years
Plum Analytics
Actions (login required)
 |
View Item |
![[feed]](http://philsci-archive.pitt.edu/style/images/feed-icon-32x32.png){kind=icon}