Another question about a Causal Fermion System

[Physics4Funn]

TL;DR Summary

Causal Fermion System and revival of Dirac Sea
https://www.physicsforums.com/threads/causal-fermion-system-and-revival-of-dirac-sea.943207/#post-5966910 ...
For modern Dirac Sea, there seems to be a revival...
Not of Dirac's original concept; the "causal fermion systems" hypothesis avoids a number of the difficulties with Dirac's original concept. However, that is still a speculative hypothesis at this point, and ... avoid the Dirac sea

What are the specific objections to Felix Finster's Casual Fermion System besides "many objections" and "very exotic, and very, very far from mainstream"?

The comment in the summary above says forget about the Dirac sea.
I am sorry, but CFS is an extension of the Dirac sea idea written in modern QFT, GR language.
Finster's been working on this for many years.

Starting with his paper on CFS as a candidate for a unified field theory is not the easiest place to begin understanding it. If you are not current and fluent with QFT and GR, start with wikipedia's Casual Fermion System article. The details are in Finster's many papers.
Here are a few references:

Finster, F. The Principle of the Fermionic Projector, hep-th/0001048, hep-th/0202059, hep- th/0210121, AMS/IP Studies in Advanced Mathematics, vol. 35, American Mathematical Society, Providence, RI, 2006.

Finster, F. Causal variational principles on measure spaces, arXiv:0811.2666 [math-ph], J. Reine Angew. Math. 646 (2010), 141–194.

Finster, F. Entanglement and second quantization in the framework of the fermionic projector, arXiv:0911.0076 [math-ph], J. Phys. A: Math. Theor. 43 (2010), 395302.

Finster, F. A formulation of quantum field theory realizing a sea of interacting Dirac particles, arXiv:0911.2102 [hep-th], Lett. Math. Phys. 97 (2011), no. 2, 165–183.

F. Finster and A. Grotz, A Lorentzian quantum geometry, arXiv:1107.2026 [math-ph], Adv. Theor. Math. Phys. 16 (2012), no. 4, 1197–1290.

After so much has been done with strings, I don't find CFS exotic.
CFS has simple, specific mental models. As a physicist, I like physical models. But who can say that combining the standard model with GR will involve simple mathematics.

Yes, CFS is speculative, but do we really have a UFT?
Probably not.
So tell me what is wrong with it.

Please, I'd really like to find the errors in Finster's work.
Someone in this world must have some understanding of his work.
I don't need a detailed, time consuming response from a busy physicist, but just a short specific answer will be helpful.

Thanks,
Ed

 

[AndyW]

I appreciate your curiosity and desire to understand Finster's Casual Fermion System (CFS). However, it is important to approach any scientific theory with an open mind and a critical eye. While there may be some valid points and interesting ideas in Finster's work, there are also several objections that have been raised by other scientists in the field.

Firstly, one of the main objections to CFS is its lack of experimental evidence. While theoretical models are important for advancing our understanding of the universe, they must also be supported by experimental data in order to be considered valid. Without any experimental evidence to back up CFS, it is difficult for other scientists to take it seriously as a candidate for a unified field theory.

Additionally, CFS has been criticized for its complexity and lack of simplicity. While it may have simple mental models, the mathematical framework behind CFS is quite complex and difficult to understand for those who are not experts in QFT and GR. This makes it challenging for other scientists to replicate and build upon Finster's work, which is a key aspect of scientific progress.

Another objection to CFS is its lack of compatibility with current knowledge in physics. As you mentioned, CFS is an extension of the Dirac sea idea, but it also deviates from mainstream theories in several ways. For example, it introduces new particles and interactions, which have not been observed or predicted by other theories. This raises questions about the consistency and compatibility of CFS with existing knowledge in physics.

Finally, one of the most significant objections to CFS is its lack of support from the scientific community. While Finster may have been working on CFS for many years, it has not gained much traction or recognition among other scientists. This could be due to the reasons mentioned above, such as lack of experimental evidence and complexity, or it could also be because other scientists have not found it to be a promising approach for a unified field theory.

In conclusion, while it is important to consider and evaluate alternative theories, it is also important to approach them with a critical and skeptical mindset. While there may be some interesting ideas in Finster's CFS, there are also several valid objections that need to be addressed before it can be considered a viable candidate for a unified field theory.