All Questions
14
questions
0
votes
2
answers
645
views
Can we regard metric as the Higgs field of gravity?
The longer version of the question is: should we regard special relativity just as a spontaneous symmetry breaking phase of general relativity, driven by the non-zero vacuum expectation value (VEV) of ...
- 4,452
1
vote
0
answers
155
views
How to use GR instead of QFT (or vice versa), if possible at all, in the sense that we can use SR instead of CM even for low-speed cases? [closed]
I asked a question on the philosophy SE - here. However, I realized this question is better suited in a Physics SE but I would rephrase it and explain my question very precisely. First, I'll mention ...
7
votes
4
answers
847
views
What does GR get right that QFT gets wrong, and vice versa?
I wondering what precisely it was, in terms of predictions of observations, that General Relativity gets right, that QFT cannot explain. And what QFT gets right, that GR cannot explain.
I'm assuming ...
- 774
15
votes
3
answers
2k
views
Does "QFT in curved spacetime" combine QFT and general relativity?
From my understanding, QFT combines QM and special relativity. So doesn't QFT in curved spacetime combine QFT and general relativity? I realize that we need to quantize gravity to have the more ...
- 577
1
vote
2
answers
204
views
Equivalence Principle holding in Special Relativity? (let alone QFT)
Motivation
I am pretty confused of why people are hopeful to find a version of the equivalence principle ("the complete physical equivalence of a gravitational field and a corresponding acceleration ...
- 1,389
4
votes
3
answers
1k
views
QFT = QM + SR? for everyday people
I understand that originally QM was a successful theory that has been experimentally proven, and was non-relativistic.
Now its successor was said to be QFT. Later on, it incorporated effects of SR, ...
- 29k
6
votes
1
answer
205
views
Spin statistical theorem in curved spacetime
In Wikipedia
https://en.wikipedia.org/wiki/Spin%E2%80%93statistics_theorem?wprov=sfti1
It states that
“The proof requires the following assumptions:
The theory has a Lorentz-invariant Lagrangian.
...
- 341
2
votes
0
answers
162
views
About the origin of the thermality in Unruh effect
It's normally understood that the thermal response in Unruh effect is related with the horizon of an accelerated observer so that part of the information is unaccessable.
In this paper, Rovelli ...
- 1,548
25
votes
5
answers
2k
views
Dependence of spin on classical vs non-classical physics?
Textbook derivations often state that spin can be derived by adding relativity to quantum mechanics. The general argument comes in several steps :
Schrödinger first tried to describe quantum ...
- 819
1
vote
1
answer
120
views
Covariant form: Determining the order of the product of tensors
Suppose ${U^\mu}_\nu$ and ${{V^\mu}_\nu}$ are matrices.
We know that in general $U^TVU \neq U V U^T$. Whenever I am reading products of the form
$${B^\gamma}_\mu = {U_{\mu}}^\sigma{{V^\nu}_\sigma}{U^...
- 1,356
1
vote
1
answer
42
views
Lifting an analogy of a pond to question signals at natural or artificial boundaries in space-time [closed]
I conjured up an idea to lift an analogy into the language of QFT and GR. I thought up the universe as a pond with a liquid. If we imagine a liquid poured into some pond (sort of bang and inflation ...
user37343
5
votes
0
answers
341
views
Weinberg-Witten theorem and Landau pseudotensor, or how QFT can make prediction about GR
Weinberg-Witten theorem states that there isn't Poincare covariant stress-energy tensor for massless fields with helicity more than $1$. The only example of such higher helicity field is graviton. ...
- 8,901
0
votes
2
answers
526
views
What if a particle falls into the center of a central field? [closed]
Given a central field $U(r)$ satisfies $U(r) \rightarrow -\infty$ when $r \rightarrow 0$, then What if a particle falls into the center of a central field? Can you help me analysis this question in ...
- 251
20
votes
4
answers
2k
views
Are gravitomagnetic monopoles hypothesized?
My understanding is that gravitomagnetism is essentially the same relativistic effect as magnetism. If so, why is it that I've heard so much about magnetic monopoles, but never gravitomagnetic ...
- 7,398