Energy condition respecting warp drives in Einstein Cartan theory

[Quantum23]

TL;DR Summary

So I read this paper where if you take the alcubierre metric calaculations while including torsion in GR you get positive energy spin requirements instead of exotic matter.

I read this paper where if you take the alcubierre metric calaculations while including torsion in GR you get positive energy spin requirements instead of exotic matter. Here is the link: https://arxiv.org/abs/1807.09745
Could it be because a spinning quantum vacuum will be less stiff like a smoke ring vortex and allow faster than light travel that the alcubierre metric doesn't violate energy condition in Einstein Cartan theory? JUst like frame dragging in GR if you have high enough spin in the form of a toroid ring you have a vortex like a smoke ring in the quantum vacuum or spacetime. It is well known that spacetime has fluid models and can have such characteristics. So are the equations really telling us the possibility of faster than light through toroidal vortices of gravitational frame dragging? If you look at a vortex ring in air, it sucks air in the front and expel it at the back with efficiency the reason that it stays longer. That is very s

 

[Dale]

So I read this paper where if you take the alcubierre metric calaculations while including torsion in GR you get positive energy spin requirements instead of exotic matter.

GR doesn’t include torsion. So if you are including torsion it is no longer GR.

 

[vanhees71]

Well, it's a pretty reasonable extension of GR from a pseudo-Riemann to a pseudo-Riemann-Cartan manifold. Since we have particles with spin 1/2 amass, it's not so unlikely that in fact the latter generalization is necessary for a full theory of gravitation and matter, though up to today there's no hint of torsion, which is because we deal with very macroscopic situations when testing GR (mostly astronomical and cosmological situations) where only scalar and electromagnetic fields are involved, and there you don't have torsion.

 

[PeterDonis]

It is well known that spacetime has fluid models

Please provide references for these models. I suspect they do not make all the same claims you are making.

 

[Quantum23]

Please provide references for these models. I suspect they do not make all the same claims you are making.

https://arxiv.org/abs/1807.09745 here is the link to a paper on alcubeierre metric in einstein cartan theory. But the fluid vortex model is made is my idea of how to interpret the results assuming that fluid analogy can be made of general relativity. You can also refer to superfluid vacuum theory in wikipedia.

 

[PAllen]

https://arxiv.org/abs/1807.09745 here is the link to a paper on alcubeierre metric in einstein cartan theory. But the fluid vortex model is made is my idea of how to interpret the results assuming that fluid analogy can be made of general relativity. You can also refer to superfluid vacuum theory in wikipedia.

Fluid vortex model cannot be both well known and your own. You have made contradictory claims.

 

[PeterDonis]

the fluid vortex model is made is my idea of how to interpret the results

Personal theories and personal speculations are off topic here at PF. Please bear that in mind.

 

[Quantum23]

Fluid vortex model cannot be both well known and your own. You have made contradictory claims.

The "fluid model" is well known as superfluid vacuum theory. But the smoke ring vortex in this fluid model is my way of interpreting the alcubierre metric in that model and I want to know what others think of the idea.

 

[PAllen]

You’re asking for an opinion on an imprecise analogy (as all are, to some degree)? That’s not really science, especially as you haven’t given the analogy any content e.g. such and such feature of the analogy corresponds to such and such feature of the Alcubierre metric.

As to another question you raise, looking over the paper briefly (though I am not very familiar with Einstein-Cartan theory), it states pretty clearly that the deviation from the GR model is all in the matter, not in the vacuum. Thus there is explicitly no new vacuum model compared to GR. What it claims is that the matter supporting and giving rise to the warp bubble need not be exotic (violating all energy conditions), if it is allowed to have high spin and that the matter is modeled with non-symmetric Ricci tensor built from connection with torsion, per Einstein Cartan theory. I am unable to comment on the validity or plausibility of this claim (of the supporting matter not being exotic), as it is outside my expertise.

 

[PeterDonis]

The "fluid model" is well known as superfluid vacuum theory. But the smoke ring vortex in this fluid model is my way of interpreting the alcubierre metric in that model and I want to know what others think of the idea.

As I've already said, personal speculations are off limits here. Since your question is about your personal speculation, this thread is closed.