Unitarity in GR+QFT: Obeying Full QG Model?

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SUMMARY

The discussion centers on the necessity of unitarity in full quantum gravity (QG) models. It highlights that current theories regarding the big bang and black hole thermodynamics may conflict with unitarity, necessitating the rejection of certain concepts. As noted by @A. Neumaier, the applicability of unitarity is model-dependent, and no fully functional model has been established yet. The conversation emphasizes the importance of discussing specific peer-reviewed models rather than abstract concepts in quantum gravity.

PREREQUISITES
  • Understanding of quantum gravity concepts
  • Familiarity with black hole thermodynamics
  • Knowledge of unitarity in quantum mechanics
  • Experience with peer-reviewed scientific literature
NEXT STEPS
  • Research specific quantum gravity models published in peer-reviewed journals
  • Study the implications of black hole thermodynamics on unitarity
  • Explore the relationship between the big bang theory and quantum mechanics
  • Investigate alternative theories that challenge traditional views on unitarity
USEFUL FOR

The discussion is beneficial for theoretical physicists, researchers in quantum gravity, and anyone interested in the foundational aspects of unitarity in advanced physics models.

Question69
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Does unitarity have to be obeyed in a full quantum gravity model?
 
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This depends on what the final unified theory will look like.

The big bang and black hole thermodynamics are quite likely inconsistent with unitarity. So something must be discarded. Different researchers have different preferences.

But this thread belongs to another forum - https://www.physicsforums.com/forums/beyond-the-standard-model.66/
 
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Question69 said:
Does unitarity have to be obeyed in a full quantum gravity model?
As @A. Neumaier says, it depends on the model. And nobody currently has one that works. But in any case, we can't discuss "quantum gravity" in the abstract. Discussion needs to be about some particular model that has been published in a peer-reviewed paper. And, as @A. Neumaier correctly points out, such discussions belong in the Beyond the Standard Model forum.

This thread is closed.
 

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