Finally, Garrett's model with 3 generations

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Discussion Overview

The discussion revolves around Garrett Lisi's paper on Lie Group Cosmology, particularly focusing on the concept of three generations of particles and the implications of exotic smoothness in four-dimensional manifolds. Participants explore theoretical connections to other works, philosophical motivations, and the potential for unifying various models in physics.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants highlight the philosophical implications of using four-dimensional manifolds and their rich structure as a motivation for Lisi's approach.
  • There are discussions about the title of Lisi's paper, with differing opinions on its pretentiousness and the adequacy of the abstract.
  • One participant questions the relationship between Lisi's model and Torsten Asselmeyer-Maluga's work, suggesting potential redundancy in their approaches.
  • Lisi acknowledges the influence of E. Weinstein's ideas, noting both collaboration and competition in their theoretical pursuits.
  • Participants express interest in the connections between Lisi's model and various approaches to Loop Quantum Gravity (LQG), particularly those developed by Bianca Dittrich and Thomas Thiemann.
  • There is a discussion about the nature of a specific particle in Lisi's model, with questions about its classification as a gauge boson versus a scalar particle.
  • Lisi emphasizes the flexibility of particle assignments within his framework and the need for empirical validation through CKM-PMNS mixing.

Areas of Agreement / Disagreement

Participants express a range of views on the implications of Lisi's model, the interpretation of its title, and the connections to other theories. No consensus is reached on the relationship between Lisi's work and that of other theorists, nor on the classification of certain particles within the model.

Contextual Notes

Some discussions reference unresolved mathematical steps and the philosophical motivations behind the theories presented. The relationship between different theoretical frameworks remains unclear, with participants exploring potential overlaps and distinctions.

  • #61
Can someone give a brief description of the model, assuming that the reader is OK with the maths. Just the general idea.
 
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  • #62

This video helps me understanding theorticlly without matematics this theory, it's very easy underdtanding the basis of the theory although video is not explaining the whole theory processes and its conclusions
 
  • #63
Hello martinbn,
The general idea of the model is to begin with a high-dimensional Lie group, which has a natural connection and metric, then embed de Sitter spacetime in this Lie group and allow the Lie group to deform, described by variations of the connection, guided by a Yang-Mills-type action extended to fermions. By choosing a nice Lie group, and allowing deformations that preserve some of the Lie group's structure, one can obtain all of the particle-fields and dynamics for the Standard Model and gravity. The model proposed in this paper is a prequel, laying a geometric foundation for previous work on E8 theory, but can be readily adapted for use with other Lie groups.
 
  • #64
Hi Garrett, and what is the problem to calculate the bare mass of an elementary particle (fermion)?

In the paper you wrote:
'...we must presume that each generation of fermions is only accessible from one of three triality-related regions of E8; only then do each of these regional fermion generations correctly match known fermion properties. Each generation will transform under a different triality-related regional spin connection...'
'...all three generations of chiral fermions transform correctly, with no mirror fermions. Also, because the vacuum Higgs field may be different in each region, each generation of fermions may have a different bare mass...'
'...the triality-related boson generators in the three regions act on the corresponding fermions in agreement with their familiar Standard Model spins and charges...'
 
  • #65
Well, this is the million dollar question. Somehow, according to this new theory, our spacetime must be a superposition of these three triality-related spacetimes, with fermions having masses related to the parameters of how these spacetimes are embedded and related. This would need to produce the (bare) masses and CKM/PMNS mixings we observe. The superposition currently posited in LGC is too simplistic to produce this -- I think the final description, if there is one within LGC, will be more... complex.
 
  • #66
To complete the theory, undoubtedly, a monumental amount of work has to be done , but maybe, you are in the right track, and your efforts could lead to the beginning of a new science revolution, which are stages required by history of science for the progress of knowledge, as T. Kuhn showed us.
 
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  • #67
Thank you, Alberto, that's very flattering. But it may also be that this new idea is wrong. I think it has a lot going for it, but I'm biased, and one always has to remember that, in science, human wishes and dreams, no matter how wonderful, can never change nature's mind. So if a theory is wrong, no matter how nice and popular it gets, it will keep being wrong.
 
  • #68
Garrett, I don't know if this exists, but, a Fourier transform is a relation that sends variables between a collection of variables where each one has a complex value. That is, it is a map that relates 2 2d spaces, where the observable is a 1D quanitty.

Your triality could mean mapping 4 3d spaces where the "meta- observable" is a 2D quantity, a complex plane. So, it's going to functions in 4 quaternions, and descending to a 2D space which is wavefunction of the the triadic object.

Depending on how you define the triality, it can yield a fermion on a boson when taking the "meta observable".
 

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