Linked Questions

21
votes
3answers
8k views

Gravity as a gauge theory

Currently, (classical) gravity (General Relativity) is NOT a gauge theory (at least in the sense of a Yang-Mills theory). Why should "classical" gravity be some (non-trivial or "special" or extended)...
18
votes
2answers
2k 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 ...
3
votes
2answers
378 views

Is general covariance a symmetry?

Is general covariance a symmetry? If it is, what is its symmetry group and corresponding generator?
7
votes
1answer
1k views

Is reparameterization invariance some kind of gauge symmetry?

On page 116 of this book it is said, that reparameterization invariance of the string action is analogous to the gauge invariance in electrodynamices. Whereas Maxwell's equations are symmetric under ...
6
votes
1answer
167 views

General relativity as a gauge theory of the Poincaré algebra

Let the Poincaré algebra be given without any factors of i as $[P_\mu,P_\nu]=0$, $[M_{\rho \sigma},P_\mu]=\eta_{\sigma\mu}P_\rho-\eta_{\rho\mu}P_\sigma$, $[M_{\mu\nu},M_{\rho\sigma}]=\eta_{\nu\rho}...
2
votes
1answer
101 views

In which contexts are gauge theories applied?

According to the book Quantum Field Theory for the Gifted Amateur, on page 128 they say A theory which had a field $A^\mu(x)$ introduced to produce an invariance with respect to local ...
1
vote
1answer
307 views

Why are string theorist so indifferent to the gauge structure of gravity? [closed]

Gravity shares many of the characteristics of Yang-Mills gauge theory. For example, the affine connection plays the similar role as the gauge potential in gauge theory, the Riemann tensor plays the ...
0
votes
1answer
1k views

Gauge transformations in gravity [duplicate]

The Maxwell equations are invariant under the transformation $$A_{\mu} \rightarrow A_{\mu} - \dfrac{1}{e}\partial_{\mu}\alpha(x)$$ where $\alpha(x)$ is a phase transformation varying from point to ...
3
votes
0answers
93 views

Why is general relativity considered to be a gauge theory? [duplicate]

I have studied the first five chapters of Carroll's book (up to the Schwarzschild solution). I see similarities to the Yang-Mill theories such as the covariant derivative to account for curvature in ...
2
votes
0answers
221 views

Does gravity have a gauge symmetry group? [duplicate]

In the Standard Model, U(1) corresponds to the electromagnetic, SU(2) to weak, and SU(3) to strong interactions. I realize that gravity is not a part of the Standard Model. However, sometimes gravity ...
1
vote
0answers
72 views

If gravity is a gauge theory, what is the Lie group? [duplicate]

Here I asked a question. In one curious comment, I see a statement that gravity is a gauge theory. However, my definition (based on what I read till date) of a gauge theory is a field theory which is ...
1
vote
0answers
56 views

Why is General Relativity considered a gauge theory? [duplicate]

Gauge theories are those which can be written with a Lie group as a symmetry group. According to Sean M Caroll's book, I can find the Lorentz group or Poincare group. So can General Relativity be a ...
0
votes
0answers
104 views

Gravity as a gauge theory - Cartan-Killing form?

First, let me state the form of Lagrangian for YM and GR \begin{align} L_{YM} = \alpha \textrm{tr}(F^2), \qquad L_{GR} = \beta R \end{align} I heard, YM is a gauge theory but GR isn't a really gauge ...