Talk:Induced gravity

Sakharov's induced gravity is NOT the same thing as discrete Lorentzian quantum gravity. This makes me suspect you are simply making up results consciously. Phys 06:46, 24 Jan 2005 (UTC)

Yes it is do a google search on "Sakharov induced gravity" and you will find the same results that I did. Please save the instults for someone who cares what you think of them. --HFarmer 03:50, 25 Jan 2005 (UTC)

Please check out this link this is just one reference from google where Discrete Lorentzian Quantum Gravity and Sakharov induced gravity are said to be the same thing. In particular go to the bottom of the page and read the last reference.

If the information I have found is incorrect the propper wikipedian thing to do would be to correct it. --HFarmer 04:01, 25 Jan 2005 (UTC)


 * The article does not state they are the same thing. It merely states that the mechanism of induced gravity also applies to Lorentzian lattice models, giving rise to the Einstein-Hilbert action with a cosmological constant. Induced gravity is a framework. Phys 04:21, 25 Jan 2005 (UTC)


 * I did correct it. Phys 04:26, 25 Jan 2005 (UTC)

No what you did is just vandalism. Instead of deleting the whole entry you would add your information or rearrange what is there to enhance the article. It really seems to me your mission is to try and discredit any theory on this cite other than string theory. --HFarmer 04:57, 25 Jan 2005 (UTC)


 * Let me get a couple of facts straight. I am NOT a string theorist and I'm not a vandal. Please don't confuse me with Lubos. And I did move your contribution to the article discrete Lorentzian quantum gravity, where it belongs. I'm not trying to discredit discrete Lorentzian quantum gravity or Sakharov's induced gravity at all. But writing induced gravity is the same thing as discrete Lorentzian quantum gravity is just plain wrong. Phys 21:37, 25 Jan 2005 (UTC)

Induced vs. Entropic
Both articles claim to also be known as "emergent gravity"... this seems really stupid. --107.77.211.108 (talk) 05:45, 18 April 2017 (UTC)

Sorry about the vandalism thing.
I have grown used to being attacked by string theorist for my views. I reacted defensivley. I am sorry.

"But writing induced gravity is the same thing as discrete Lorentzian quantum gravity is just plain wrong." Let me explain why I thought that equateing them was correct by way of a thought experiment. Lattice methods of quantizeing the background have as an assumption that physical lenths can only be scalar multiples ofthe planck lenth $$\sqrt G$$ (choose units such that $$\hbar^{2}=c^{2}=1$$). If you take a mass that is less than the planck mass and collapse it what happens? The formula for the Schwarzschild radius is $$R_{schwarzschild}={2GM}$$ Say our test mass is 0.99 of the planck mass ($$\frac{1}{\sqrt G}$$).

$${2G(0.99)\frac{1}{\sqrt G}}=1.98\sqrt G$$

The implication of this is that a only a mass $$\frac{n}{2}\sqrt G$$ multiple of the planck mass will generate a gravitational field. So in this way the lattice type method of quantiseing space time is a quantum version of induced gravity. FYI the planck mass is $$2.176x10^{8}kg$$ compared to a quantum particle that is a bulk of mass.

--HFarmer 15:28, 26 Jan 2005 (UTC)

Theorist suggests: The term Induced Gravity must be think over as a resulting gravitational field created around any material body standing in the space already affected by a main gravitational field whose origin can be placed anywhere; That is if there not exist a main gravitational field no Induced Gravity can be detected at all. ==[User:protaldo ] 23:12, 17 may 2005 (utc)

Induced versus emergent gravity
The two are not exactly the same. Sakharov's induced gravity assumes a pre-existing metric field $$g_{\mu\nu}$$ and Sakharov's idea is that (under some very general assumptions) it will automatically lead to Einsteinian dynamics. In emergent gravity, the metric $$g_{\mu\nu}$$ emerges naturally, e.g. from a condensed-matter system. It is not assumed to pre-exist. The problem in emergent gravity is precisely that it doesn't necessarily obey Einstein dynamics. In particular, in the case of condensed-matter systems, when expanding the action series, the hydrodynamic terms are in general dominant over the Einstein-Hilbert term. It should be added that the term emergent gravity has become a buzzword and is being used in a lot of different meanings lately. (Imtg5102 (talk) 14:40, 18 April 2008 (UTC))

Unclear sentence
"Developments in AdS/CFT correspondence after 1997 suggest that the microphysical degrees of freedom in induced gravity might be radically different. " Different to what? 1Z (talk) 16:55, 16 July 2011 (UTC)

Easier to Understand for a Layperson
Is it possible to make this article more accessible to a layperson? I ended up on this article and found it pretty hard to follow. Could somebody add an intuitive example, explanation or some diagrams to help? Cristiklein (talk) 22:59, 17 December 2016 (UTC)

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