Tagged Questions
7
votes
1answer
257 views
Diffeomorphisms, Isometries And General Relativity
Apologies if this question is too naive, but it strikes at the heart of something that's been bothering me for a while.
Under a diffeomorphism $\phi$ we can push forward an arbitrary tensor field $F$ ...
8
votes
4answers
332 views
To which extent is general relativity a gauge theory?
In quantum mechanics, we know that a change of frame -- a gauge transform -- leaves the probability of an outcome measurement invariant (well, the square modulus of the wave-function, i.e. the ...
1
vote
1answer
148 views
observable quantities are gauge invariant?
I have a simply question, that is whether spatial velocity is gauge invariant.
It is seems that under a infinitesimal coordinate transformation the velocity is just transform as other vectors, and it ...
5
votes
3answers
246 views
Could general relativity and gauge theories in principle be covered in one course?
It's always nice to point out the structural similarieties between (semi-)Riemannian geometry and gauge field theories alla Classical yang Mills theories. Nevertheless, I feel the relation between the ...
5
votes
2answers
84 views
Torsion and gauge invariant EM kinetic term
Everytime I hear about adding torsion to GR, something struggles me: how do you create a kinetic term for the electromagnetic field that is still gauge-invariant? One of the consequences of torsion is ...
8
votes
1answer
321 views
argument about fallacy of diff(M) being a gauge group for general relativity
I want to outline a solid argument (or bulletpoints) to show how weak is the idea of diff(M) being the gauge group of general relativity.
basically i have these points that in my view are very solid ...
2
votes
2answers
289 views
Diff(M) and requirements on GR observables
This question is kind of inspired in this one:
Diff(M) as a gauge group and local observables in theories with gravity
The conundrum i'm trying to understand is how is derived the (quite) ...
