Questions tagged [stress-energy-momentum-tensor]

A symmetric rank-2 tensor in relativity, which expresses the flux of energy-momentum along timelike and spacelike axes. Also known as the stress tensor or the energy-momentum tensor. In the Einstein field equations, it is the source of gravitational fields.

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Analog between Electromagnetism and Gravity

Feynman makes an analogy between EM field and gravity field in his Feynman's Lectures on Gravitation. The vector field representing EM potential would couple to the current source(vector) in the ...
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Does the isotropy definition of a perfect fluid imply no heat conduction?

Weinberg defines a perfect fluid (Chapter 2, Section 10) as one where each fluid element appears isotropic in a reference frame moving with that element. From the definition of the stress-energy ...
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Energy-momentum tensor and equation of motion in Einstein-Dilaton theory [closed]

I am following this paper (see eq. 19-22) and trying to derive the equation of corresponding to Einstein-Dilaton gravity (ignoring the Maxwell part for now) \begin{align} S_{\text{E-D}} = \int d^4 ...
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How can the stress-energy tensor $T^{μν}$ be unique when the Lagrangian $L$ is not?

A relation (or definition) between the stress-energy tensor and the Lagrangian in GR is routinely seen: $$T^{μν} = -2 \frac{∂L}{∂g_{μν}} - g^{μν} L \quad\quad(*)$$ (or some variation of this, ...
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Does (covariant) divergence-freeness of the stress-energy tensor ${T^{\mu\nu}}_{;\nu}=0$ follow from the Bianchi identity?

I'm working through Chap. $30$ of Dirac's "GTR" where he develops the "comprehensive action principle". He makes a very slick and mathematically elegant argument to show that the ...
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Zero stress in $z$ components for thin surfaces

We can write the stress tensor as: T= \left [ \begin{array}{ccc} \sigma_r & \tau_{r\theta} & \tau_{rz} \\ \tau_{\theta r} & \sigma_\theta & \tau_{\...
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Question on linear perturbations in cosmology

I've been studying clustering dark energy when I came across a paper named "A Short Review on clustering dark energy" by Ronaldo Batista. there are 2 equations in this paper (eq.8 and eq.9) ...
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Pressure as momentum flux versus momentum of fluid flow

I've read in multiple sources (for example, Thorne and Blandford, Modern Classical Physics, pg 83 and Schutz, A First Course on General Relativity pg 92) that the stress components of the stress-...
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