Stress-energy tensor in static cylindrical case

In summary, the speaker discusses using a definition for T^{\mu\nu} that may not be valid in all coordinate systems. They then present a Weyl metric and use the Einstein equations to show that the resulting T_{11}=-T_{33} contradicts the result obtained from the first formula. The speaker expresses confusion and asks for an explanation.
  • #1
ArthurB
17
0
I have some problems using this definition, maybe because it's not valid in every coordinate system:

[tex]
T^{\mu\nu} = (\epsilon + p) \frac{dx^{\mu}}{ds} \frac{dx^{\nu}}{ds} -p g^{\mu\nu}
[/tex]

since in cylindrical coordinates
[tex]
x^0 =t \qquad x^1 =\rho \qquad x^2 = \phi \qquad x^3 =z
[/tex]

using weyl metric
[tex]
g_{00}= e^{2u} \qquad g_{11}=-e^{2v-2u} \qquad g_{22}=-\rho^2 e^{-2u} \qquad g_{33}=-e^{2v-2u} \qquad u=u(\rho,z) \qquad v=v(\rho,z)
[/tex]

I obtain
[tex]
T_{11}=T_{33}
[/tex]

but from the definition of the einstein tensor I obtain
[tex]
G_{11}=-G_{33}
[/tex]

but einstein equation says
[tex]
G_{\mu\nu}=8\pi k T_{\mu\nu}
[/tex]

which in this case then implies
[tex]
T_{11}=-T_{33}
[/tex]

in contraddiction with the result obtained from the first formula.
can anyone explain?
 
Last edited:
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  • #2
To make the math show up correctly, you need tex and /tex (or itex and /itex for inline equations), not latex and /latex.
 
  • #3
thanks, corrected. Do you have any clue about the problem?
 
  • #4
I find G33 =-G22 also.

I would not expect this Einstein tensor to be that of a perfect fluid.
 
Last edited:

1. What is the stress-energy tensor in the static cylindrical case?

The stress-energy tensor in the static cylindrical case is a mathematical object that describes the distribution of energy, momentum, and stress in a cylindrical system that is not changing over time. It is a 4x4 matrix with 10 independent components that represent the different components of energy and momentum, such as mass density, pressure, and shear stress.

2. How is the stress-energy tensor calculated in the static cylindrical case?

The stress-energy tensor can be calculated using the Einstein field equations, which relate the curvature of spacetime to the distribution of matter and energy. In the static cylindrical case, the equations can be simplified to solve for the stress-energy tensor.

3. What is the physical significance of the stress-energy tensor in the static cylindrical case?

The stress-energy tensor describes the energy-momentum content of a system, which is important in understanding the behavior of matter and energy in the presence of gravity. It can also be used to calculate the gravitational field, which is crucial in understanding the dynamics of objects in a cylindrical system.

4. How does the stress-energy tensor in the static cylindrical case differ from other cases?

The stress-energy tensor is a general concept that can be applied to different systems. In the static cylindrical case, it is specifically used to describe the distribution of energy and momentum in a cylindrical system that is not changing over time. This is different from other cases, such as the stress-energy tensor in the presence of a rotating black hole.

5. What are some applications of the stress-energy tensor in the static cylindrical case?

The stress-energy tensor is used in various fields of physics, such as general relativity and astrophysics, to study the behavior of matter and energy in cylindrical systems. It is also important in understanding the dynamics of objects, such as stars and galaxies, in these systems. Additionally, the stress-energy tensor is used in the development of theoretical models and for making predictions about the behavior of matter and energy in the universe.

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