[Req]Help finding equation

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Discussion Overview

The discussion revolves around the search for an equation that formulates general relativity into a quantum field theory, as mentioned by Michio Kaku in the TV show "Seeing Black Holes." Participants explore concepts related to quantum gravity, non-renormalizability, and various theoretical proposals in the context of this equation.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant requests the specific equation related to general relativity and quantum field theory discussed by Michio Kaku.
  • Another participant suggests a book by Martin that contains a chapter on Quantum Gravity, indicating it may provide relevant insights.
  • A participant explains that a quantum field theory of gravity is non-renormalizable due to the negative mass dimension of the gravitational coupling constant, G.
  • There is mention of the Wheeler–DeWitt equation as a possible relevant equation in the context of quantum gravity.
  • Some participants note that there is no settled theory of Quantum Gravity, but various proposals exist, including a supersymmetric theory referred to as "super-gravity." One participant mentions a Lagrangian associated with this theory as stated by Kaku.

Areas of Agreement / Disagreement

Participants generally agree that there is no settled theory of Quantum Gravity, and multiple competing views and proposals remain in the discussion.

Contextual Notes

There are unresolved aspects regarding the specific equation sought by the original poster and the implications of the various theories mentioned, including the nature of non-renormalizability and the specifics of the proposed supersymmetric theory.

kazparov
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In the TV Show Seeing Black Holes, from the Science Channel professor Michio Kaku speaks about an equation to formulate general relativity into a quantum field theory witch leads to a infinite sequence of inifinities

i would like to see that equation if possible.

i tried google, but no luck so far

thank you for any help

Kazparov
 
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Hi kazparov!

In his book "Quantum Field theory - a modern introduction" there's a chapter on Quantum Gravity. If you don't know where to find the book, just send me a PM.

best regards, Martin
 
I guess he refers to the fact that a quantum field theory of gravity would be non-renormalizeable. This can be easiliy seen from the dimension of the coupling. If one tries to quantize the classical field theory of gravity (General relativity), one faces the problem that the coupling constant (G in Newton's law), the gravitational constant, has negative mass dimension. Therefore the theory is non-renormalizeable.
Actually the chapter in his book is quite interesting, unfortunately I don't have the time to read it. In chapter 19.10 he discusses why non-renormalizeabilty is not a problem in principle. He says: "although quantum gravity is formally nonrenormalizebale, we can still hope that (by a series of miracles) the divergences of the quantum loops cancel, leaving us with a finite theory".

I hope you find answers to your questions in his book (which is really a good one!).
 
Sunset said:
Hi kazparov!

In his book "Quantum Field theory - a modern introduction" there's a chapter on Quantum Gravity. If you don't know where to find the book, just send me a PM.

best regards, Martin

Hello, thank you very much for your reply

Does the book have the equation?, i just want to have a look at the equation

Thank you

Kazparov
 
You might be looking for Wheeler–DeWitt equation
 
As far as I know there is no settled theory of Quantum Gravity so far. However, there are proposals.
One of these proposals, as far as I understood Kaku, is a supersymmetric theory, so called "super-gravity".
He states the Lagrangian in chapter 20, I attached it.

Best regards
 

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Sunset said:
As far as I know there is no settled theory of Quantum Gravity so far. However, there are proposals.
One of these proposals, as far as I understood Kaku, is a supersymmetric theory, so called "super-gravity".
He states the Lagrangian in chapter 20, I attached it.

Best regards

thank you very much

and thank you LostConjugate

both of your replies have been very helpful

much appreciated
 

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