New answers tagged stress-energy-momentum-tensor
0
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Does Cauchy stress tensor act on $SO(3)$?
Cauchy’s theorem, under standard physical laws of continuous bodies proves that the stress vector $s$ at $p$ referred to the normal unit $n$ has the form
$$s(p,n)_k = \sigma(p)_{kj} n_j.$$
Above, I ...
- 75.8k
3
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Accepted
Where this definition $T_{\alpha\beta}=-\frac{2}{T}\frac{1}{\sqrt{-h}}\frac{\delta S}{\delta h^{\alpha \beta}}$ come from?
Because by construction, it satisfies 3 key properties one expects from the energy-momentum tensor:
It is a symmetric rank-2 tensor,
By an infinitesimal coordinate transformation $x^\mu\to x^\mu+\xi^\...
- 1,120
2
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Time dependence of momentum operator in QFT
I stress that I am interpreting $\langle \cdots \rangle$ as an expectation value with respect to the Poincaré invariant vacuum.
Barring mathematical technicalities, the conservation law can be stated ...
- 75.8k
4
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Does a change in the trace of the stress-energy tensor when a particle passes through an event horizon violate energy conditions?
When a particle crosses the event horizon of a black hole, its stress-energy tensor undergoes a change in sign
This statement is not a valid statement. The stress-energy tensor is a tensor, not a ...
- 105k
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