0
$\begingroup$

I see that the definition of the stress-energy tensor refers to the flux of momentum across a surface but given the example of a collection of electrons confined to a box (volume in space), even with no macroscopic flow, the potential energy of the electrostatic repulsion between the electrons would surely contribute to the stress-energy of the system? A similar scenario with neutral particles would have less energy correct? But if the stress-energy tensor is defined in terms of flux, and there is no flow of mass in the box, then how is this potential energy accounted for?

All of the examples I have seen dealing with the stress-energy tensor discuss ideal fluids. I assume this model can actually be applied to any arbitrary configuration of matter, accounting for non-ideal characteristics such as molecular bonding and electrostatic potential energy?

$\endgroup$
0
$\begingroup$

The stress in an arbitrary condensed phase can be expressed atomistically as given here. As you can see, there are two contributions to the stress: a kinetic energy term and a work term. At low temperatures, or even at room temperature in crystals, the work term dominates the stress. In liquids though, the kinetic term dominates.

| cite | improve this answer | |
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.