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### What are the properties of metric tensor? [duplicate]

It's frequently said that graviton has spin-2, so its wave function should have $5$ independent components. The metric tensor has $n^2=16$ components, but it obeys the following property: \begin{...
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### Why gravitational waves have 2 possible polarizations? [duplicate]

I was under the impression that light waves have 2 polarizations because even if the photon is spin 1, the photon is massless which imposes additional constraints. In the case of gravity, it is ...
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### Degrees of freedom of the graviton versus classical degrees of freedom

I have a puzzle I can not even understand. A graviton is generally understood in $D$ dimensions as a field with some independent components or degrees of freedom (DOF), from a traceless symmetric ...
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### Counting degrees of freedom of gauge bosons

Gauge bosons are represented by $A_{\mu}$, where $\mu = 0,1,2,3$. So in general there are 4 degrees of freedom. But in reality, a photon (gauge boson) has two degrees of freedom (two polarization ...
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### Propagating degrees of freedom of graviton

What is the best way to see that the number of propagating degrees of freedom or gravitons in 3 dimensions is $0$ ? By graviton I mean the metric and NOT some topologically massive graviton that one ...
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### Degrees of freedom in General Relativity

A way one counts degrees of freedom(i.e. independent entries of the metric tensor ) in General Relativity is this: one goes to the linearized version, vacuum solution, and he sees that there are two ...
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### Notion of 'functional degrees of freedom' for the metric function in GR?

I have read through the numerous questions on 'degrees of freedom' in the metric tensor, and won't list them all here. However none of them address my question on 'functional' degrees of freedom in ...
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### How many independent degrees of freedom does the metric tensor have in vacuum (at every point)?

A field of metric tensors fully characterises the curvature of a vacuum space-time. (For example, the spacetime between some single point masses which are themself not part of the manifold) The metric ...
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Air molecule has $6$ degrees of freedoms: it can move up & down, left & right, front & back, rotate along $x$-axis, $y$-axis, $z$-axis. But I heard about graviton, a hypothetical particle ...