Quantum field theory, spacetime, and coordinates

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Discussion Overview

The discussion revolves around the interpretation of Dirac matrices and fields under spacetime coordinate transformations in the context of quantum field theory (QFT) and general relativity (GR). Participants explore the implications of different pedagogical approaches to these transformations, the role of tetrads, and the relationship between energy, mass, and gravity.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants express skepticism about the concept of relativistic mass in GR, suggesting it is more coherent in special relativity (SR).
  • There is a proposal to adopt a reverse pedagogy regarding the transformation of fields and matrices, similar to that used in GR.
  • Some argue that using tetrads is necessary to make sense of spinors in GR, while others question whether this is required in their proposed formalism.
  • Concerns are raised about the physical interpretation of non-covariant quantities in GR, with some suggesting that teaching should focus on energy rather than mass as the source of inertia.
  • Participants discuss the equivalence of different formalisms in Minkowski spacetime and the implications for generalizing to curved spacetimes.
  • There is a debate about whether treating Dirac fields as scalars leads to different results in GR compared to the standard spinor approach.
  • Some express skepticism about the applicability of the proposed formalism in QFT, particularly regarding the treatment of Poincaré transformations and the structure of Hilbert spaces.

Areas of Agreement / Disagreement

Participants do not reach a consensus, as multiple competing views remain regarding the treatment of Dirac fields, the necessity of tetrads, and the interpretation of mass and energy in the context of gravity.

Contextual Notes

Limitations include unresolved questions about the physical interpretation of non-covariant quantities in GR and the dependence of various arguments on specific definitions and assumptions about spacetime and fields.

  • #61
rubi said:
I don't think there are any relativists who use a different definition.

Just to note, this thread is in the quantum forum, not the relativity forum, so the question is really what definition quantum field theorists use.
 

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