A Volovik vs Witten vs Wen, etc.

[Fractal matter]

Lets suppose Volovik and Wen are right. Can their many-body systems be approximations of a more fundumental QFT ?

 

[Demystifier]

Lets suppose Volovik and Wen are right. Can their many-body systems be approximations of a more fundumental QFT ?

In principle, yes. In principle, we could even have an infinite regress: many-body system emerging from a QFT, which emerges from a many-body system, which emerges from QFT, which ...

 

[Fractal matter]

In principle, yes. In principle, we could even have an infinite regress: many-body system emerging from a QFT, which emerges from a many-body system, which emerges from QFT, which ...

As i understand it, the critical speed in that more fundamental QFT will be even faster and one gets usual criticism.

I wonder if QM and QFT may correspond to particular scales(approximations) of deterministic dynamic fractal system. I have a sense it does. For example in renormalization group Schröder's equation is used, which is said to be suitable to encoding self-similarity. Quote from wikipedia: "Iterated functions are objects of study in ... fractals, dynamical systems ... and renormalization group physics."

Giulio Prisco shares the view to some extent: https://turingchurch.net/down-in-the-fractal-depths-of-quantum-matter-and-space-time-fe0c83b3516

I'd like to know if Ervin Goldfain and Gianluca Calcagni pursue the same idea.

https://www.academia.edu/22396275/R...ndom_fractal_topology_in_quantum_field_theory

https://www.researchgate.net/publication/230802696_Introduction_to_Multifractional_Spacetimes
https://www.researchgate.net/publication/301842283_Lorentz_violations_in_multifractal_spacetimes

 

[Demystifier]

As i understand it, the critical speed in that more fundamental QFT will be even faster and one gets usual criticism.

If more fundamental QFT is not relativistic, i.e. if its action is not Lorentz invariant, then there does need to be a critical speed at all.

 

[Fractal matter]

If more fundamental QFT is not relativistic, i.e. if its action is not Lorentz invariant, then there does need to be a critical speed at all.

For observers restricted to using sound clocks and rods the action will be Lorentz-invariant(arXiv:1612.06870v2). So it seems the symmetries of the action describe the qualities of the observer.

we could even have an infinite regress: many-body system emerging from a QFT, which emerges from a many-body system, which emerges from QFT, which ...

I cherish this view on qm together with superdeterminism. Also Wolfram's rewriting rules are interesting in this context. Is this a bunch of effective qft's(and corresponding observers of different types) each possessing its own symmetries? Or is the word effective inappropriate, because there are different qft's/spacetimes involved? Can this be considered as a single qft? What's different, it seems, are types of observers.

 

[Giulio Prisco]

Is it Volovik using quantum mechanics as more fundamental to QFT?

At the very end of his book Volovik says that (something like) QFT can be derived from his superfluid vacuum theory but QM is still fundamental, so yes. He also says that further research could also explain the origin of QM: “However, in exploring the quantum liquids with Fermi points, we are probably on the right track toward understanding the properties of the quantum vacuum and the origin of quantum mechanics.”

Besides that, I’m resurrecting this thread to ask this: I have the impression that something analogous to string theory could be also derived in Volovik’s approach. OK different number of dimensions but perhaps the superfluid vacuum could be described by a QFT with a string dual? Now this would be an intriguing unification! Any pointers?

Edited: this seems a good pointer:
https://www.nature.com/articles/478302a

And a book:
https://www.amazon.com/dp/1107080088/?tag=pfamazon01-20

Will post others.

 

[Giulio Prisco]

Essentially, because I don't like superdeterminism. Superdeterminism says that correlations are not due to laws of physics, but are contingent properties of special initial conditions. In this way, superdeterminism can nominally explain anything but actually explains nothing.

If Nicolas Gisin is right then superdeterminism is trivially true BUT the world is NON-deterministic!

https://www.quantamagazine.org/does...from-a-century-old-approach-to-math-20200407/

 

[Giulio Prisco]

Among the offered options, I think 6. describes it the best. But unfortunately the notion of "ether" is often associated with crackpottery, so if you want to avoid such a negative connotation, you can use a more straight notion, perhaps effective theory physics or emergent physics, suggesting that the theories that we currently know are effective theories that emerge from as yet unknown more fundamental physics.

Superfluid vacuum physics seems good to me.

 

[MathematicalPhysicist]

If Nicolas Gisin is right then superdeterminism is trivially true BUT the world is NON-deterministic!

https://www.quantamagazine.org/does...from-a-century-old-approach-to-math-20200407/

The laws of physics imply that the passage of time is an illusion.

No need to read any further, "time is an illusion".
If the laws of physics imply that, would you like to change them?
I asked if the poster Creator still posts in PF once, but it seems he had stopped posting.
We can ask him/her...

 

[Giulio Prisco]

No need to read any further, "time is an illusion".
If the laws of physics imply that, would you like to change them?
I asked if the poster Creator still posts in PF once, but it seems he had stopped posting.
We can ask him/her...

The quotes are formatted in a way that gives the impression that I said "The laws of physics imply that the passage of time is an illusion," but I didn't say and don't think that!

 

[MathematicalPhysicist]

The quotes are formatted in a way that gives the impression that I said "The laws of physics imply that the passage of time is an illusion," but I didn't say and don't think that!

Of course not, it's written in the first line in the link you gave.

 

[Fractal matter]

I am very much interested in the subject. My view is very well described in the article by Giulio Prisco - "Down in the fractal depths of quantum matter and space-time". The world, it seems, can be described as infinite series of approximations/effective fields.

I'm convinced, physicists are able to derive the speed of light, using the same methods they use, when they derive a speed of sound in a medium. Quote:
'Inside such a vacuum structure, the speed of light would not be the critical speed for vacuum constituents and propagating signals. The natural scenario would be the superbradyon (superluminal preon) pattern we postulated in 1995, with a new critical speed cs much larger than the speed of light c just as c is much larger than the speed of sound.' - Luis Gonzalez-Mestres.

There is an inherent preferred frame of reference in that scheme, as far as I understand it. It seems plausible to me, there is an infinity of 'vacua', each possessing different critical speed c1 << c2 << c3 << ... I wonder, if there is a possible connection to fractal geometry.