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  4. On Ideas towards a Quantum Theory of Gravity
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On Ideas towards a Quantum Theory of Gravity

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Offline Dubbelosix (OP)

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Re: On Ideas towards a Quantum Theory of Gravity
« Reply #20 on: 11/09/2017 05:33:21 »
We stated previously that to answer our problems, it may be that the distribution of mass in superpositioning does not give rise to true equilibrium. Penrose's model seems to be based very much on the same situation:

''The superposed lump plays the role of the Schrodinger’s cat. Supposing the gravitational field of the lump and that each lump location separately represents a stationary state and that energy in each case is the same, can we conclude that the quantum superposition of the two lump locations is a stationary state? Penrose using the profound conflict between general covariance principle and superposition principle, asserts that gravity is responsible for an objective reduction of quantum states, accordingly such superposition is not stationary and collapses (Penrose 1996).''

'' General covariance principle implies that in absence of any spatial inhomogeneity in the background potentials, there is nothing in the intrinsic nature of the lump location that allows us to distinguish it from any other lump location, whereas to sense the quantum superposition of lump locations, those locations must be distinguishable. In other words, to have just a single Schrodinger equation governing the evolution of the superposed quantum system, we have to identify those two space–times and according to the general covariance principle there is no canonical way of asserting which point of one space–time is to be regarded as the same point in another. ''


https://link.springer.com/article/10.1007/s40995-016-0024-9
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Re: On Ideas towards a Quantum Theory of Gravity
« Reply #21 on: 11/09/2017 20:20:00 »
Penrose has suggested a graviational self energy related to a collapse time model

694be4db2633014166e2a2c2979223ef.gif

And in the Penrose model, the energy is given as

da202015857b71be6b26789b90c0a7c8.gif

We can derive a more general case that can be used to measure the density variations of spacetime. Deriving the gravitational binding between any coherent gravitational superpositioning state can be given the following way:

The gravitational field inside a radius 183b157849e987a4f60a759b8d0c9521.gif is given as

b1a9189375045c8c1333f2538eac7f53.gif

and the total mass is

1482bd65300b5963119f93f7c500ca69.gif

and so can be understood  in terms of energy (where 43943769afb6699fc5ce5a68ec70ed3f.gif is the time-time component of the metric),

aa2bcf7f96e91567f0476569aa6087f8.gif

The difference of those two mass formula is known as the gravitational binding energy:

6ab1ee6e13cf1f76405999f4b322eead.gif

Distribute c^2 and divide off the volume we get:

9123e4e7b36b29ecfbd54c96fff76abe.gif

Were we have used a notation c7d34ed23760291c386298d66670ec30.gif for the energy density. Fundamentally, the equations are the same, just written differently. Notice that c3abb70e4e08e6f6cca85c0339a38669.gif from Poisson's formula, in which we notice the same terms entering

6ab1ee6e13cf1f76405999f4b322eead.gif

da202015857b71be6b26789b90c0a7c8.gif

So while Penrose suggests calculating the binding energy directly from the gravitational potential 1ed346930917426bc46d41e22cc525ec.gif there are ways as shown here, to think about it in terms of the gravitational energy density and the gravitational binding between the two.

Now, J. Anandan has postulated an equation with dimensions of energy

e64a5d58bb55e135f37163e20d3c847b.gif

He postulates a fluctuation of the connection c6aaf4d027766fec3e48899ea29a7e1b.gif and proposes the gravitational fields of the superpositioned states may be regarded as peturbations on the background Minkowski spacetime and suggests

9f1162b814a6acdabfd2a80f74a4b43f.gif

Where we have removed Dirac notation because of the sites sensitivity to certain symbols and format. It's an interesting equation that needs to be understood better for it shares formal similarities to the approach we took in a Hilbert space:

e449bb672b251ecac51a212283a3e086.gif

As an expectation value on curvature tensor. When we think of a connection like 44e798dd0e5c68dfc3de1455721e0a72.gif really, what is being suggested, is a covariant derivative and a connection term

355e1ea992e868b9d1f9ea8215ed38bf.gif

and with the indices and extra terms, it just becomes a more complicated object known as the curvature ternsor 73108f581865e92dda72167e3668e993.gif. In theory, we should be able to replace 44e798dd0e5c68dfc3de1455721e0a72.gif for the curvature tensor.



http://sci-hub.bz/10.1007/BF02105068
« Last Edit: 11/09/2017 20:48:43 by Dubbelosix »
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Offline Dubbelosix (OP)

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Re: On Ideas towards a Quantum Theory of Gravity
« Reply #22 on: 11/09/2017 20:56:02 »
''Now, J. Anandan has postulated an equation with dimensions of energy

e64a5d58bb55e135f37163e20d3c847b.gif

He postulates a fluctuation of the connection c6aaf4d027766fec3e48899ea29a7e1b.gif and proposes the gravitational fields of the superpositioned states may be regarded as peturbations on the background Minkowski spacetime and suggests

1cf58b1d2103a3deccb7f2d8ad9a2cbe.gif

Where we have removed Dirac notation because of the sites sensitivity to certain symbols and format. It's an interesting equation that needs to be understood better for it shares formal similarities to the approach we took in a Hilbert space:

e449bb672b251ecac51a212283a3e086.gif ....''



Let's explore this first equation by Anandan by studying the dimensions. I thought what was supposed to be implied here from his 'proposed' constant of proportionality, was the speed of light to the power of four, which is an equation with dimensions identical to an energy of the form

49ba82f6134b6239745346f5704b323d.gif

So while the author did not specify, did they set 4a8a08f09d37b73795649038408b5f33.gif to natural units and keep the definition of the Newtonian constant in there?

The equation does have non-commutative properties in d71d23c081aede6e419de98dda10ebae.gif it should be noted. Taking both equations and looking at the structure

a117f9d039e2fcb2b42d52ebb521ac45.gif

e64a5d58bb55e135f37163e20d3c847b.gif

The equations are very similar.

« Last Edit: 11/09/2017 21:00:01 by Dubbelosix »
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Offline Dubbelosix (OP)

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Re: On Ideas towards a Quantum Theory of Gravity
« Reply #23 on: 11/09/2017 23:01:59 »
The dimensions of his equation

e64a5d58bb55e135f37163e20d3c847b.gif

doesn't make much sense to me... I mean, I could very well be wrong or missing something. I did try and construct some kind of meaning out of it though.

So what is the difference between the two equations?

a117f9d039e2fcb2b42d52ebb521ac45.gif

e64a5d58bb55e135f37163e20d3c847b.gif

Firstly, I should have noted that the first equation uses a dimensionless interpretation of 1ed346930917426bc46d41e22cc525ec.gif which you can expand in a series, which can be thought of as ''gravitational corrections.'' Knowing that the operator has dimensions of inverse length squared ceba5695587e82b7e7412c379236f7c1.gif and since the first term is a gravitational force ceb0010a2e306e2397a90e87ddcfbf5d.gif, we end up with an equation (with dimensions of e453713c07f1160eb33eb9b96ad85e85.gif which is exactly the dimensions of energy. Going to the second equation I am wondering if there is a typo in the equation and really what we want is

aac80ad527ef9c1fef68a75848f2bbec.gif

can be written also then as

1e694211baf5544404ce72df3e932d46.gif

We may identify the squared value of the divergence ea896207b8a8710b92eb4cb54626e20c.gif is the Laplace operator. This means his equation can be written as

2d34f04dc1a1a372f7c37bd29690db30.gif

Now compare

a77d24e9e2e30ab50dcdd14dd07d817c.gif

An integral on the RHS of the first equation will yield

e8aadb2ecb8eb4e62d02257ea836508f.gif

Which does have dimensions of energy iff the connection is of dimensionless form and the missing constant of proportionality is 6d75747fe76cff19a17b175d33b90e1a.gif to fix the dimensions. So

864ff0ea99f266de79299f68aac355e7.gif

Is an energy density and the energy is simply

c6976de6ad7c22988f6ea4e0d8a3fe96.gif

Is it possible that such a mistake occurred somewhere? Because the other form doesn't make much sense to me.
« Last Edit: 11/09/2017 23:13:43 by Dubbelosix »
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Re: On Ideas towards a Quantum Theory of Gravity
« Reply #24 on: 12/09/2017 00:11:41 »
The notation seems a bit odd to me, for if the previous equation is not what he meant then 967878d1da852d4b07a961e3168b0fff.gif may not be the Laplacian. It seems at least, from his fluctuation equation, it could be like a difference operator, in which case, we don't usually square it. The similarities though, were interesting. Even if it was a difference operator, the dimensions of his equations would not make sense to me.

So... really, we can replace the ... inspiring 07710b5c43702a8bb7b9104eacc6ba71.gif for the curvature tensor itself. The difference in quantum geometries in a Hilbert space is

fb01c73e2380ec10e544c3c8d545a2ff.gifb4d3ac41daa087b6ff6b7564c9749d2e.gif

*Check this with the early construction!

Where we have used 967878d1da852d4b07a961e3168b0fff.gif as a difference operator, in the same manner it seems, as Anandan. In his equation, an element volume term is attached to it, why, I am not sure. We have kept it out of this definition. The equation just proposed, is the proving ground of unitarity and whether the system obeys it. This equation doesn't tell you whether it does.





« Last Edit: 12/09/2017 00:17:44 by Dubbelosix »
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Re: On Ideas towards a Quantum Theory of Gravity
« Reply #25 on: 12/09/2017 00:24:35 »
If instead now, his equation


e64a5d58bb55e135f37163e20d3c847b.gif

Is not treating 659d23f0ed16cdb87b1d41c7b58b52f4.gif as the Laplacian, but instead a difference operator, and if 07710b5c43702a8bb7b9104eacc6ba71.gif now has conventional dimensions of 1/length then an integral yields a true energy equation

1a261e352b78da626c2b088e7ec26982.gif

Which would make sense of the element volume attached to his curvature/geometry probability difference and in a case where he set ea720431a22935412ba226ccd6548300.gif. In which case, you should still be able to write the following:

b272ffcc7387196e5918ec455fe128df.gif

Where we do not square the operator this time.
« Last Edit: 12/09/2017 00:38:02 by Dubbelosix »
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Re: On Ideas towards a Quantum Theory of Gravity
« Reply #26 on: 12/09/2017 01:29:20 »
So yeah, the really confusing thing here, and don't worry, I was confused as well, it doesn't actually matter whether the coefficient of the Christoffel symbol is the nabla operator is replaced with a difference operator. The results appear to be the same either way, which is good. We will go back to this description of Anandan's picture later when I have developed more theory.
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Re: On Ideas towards a Quantum Theory of Gravity
« Reply #27 on: 12/09/2017 02:32:17 »
Ah! Just one last thing to wrap up, the equation whcih describes the binding energy of the superpositioned geometry

1e694211baf5544404ce72df3e932d46.gif

with b50117bc5a2bbed4e38999e20214135c.gif as the difference operator.

1cf58b1d2103a3deccb7f2d8ad9a2cbe.gif

We have established, what is really meant with equation 1. is

bfd7b37e602792dff03c28fe89185400.gif

We have argued, that the squared component of the connection can be interpreted in terms of the curvature tensor. This is related to the difference of geometries and that is given now as a full energy equation with

5e450ce1c9cd15d38c4823a764cfb346.gifb0061f05b696776e52b899a372e8d684.gif
« Last Edit: 13/09/2017 02:00:50 by Dubbelosix »
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Re: On Ideas towards a Quantum Theory of Gravity
« Reply #28 on: 13/09/2017 07:24:01 »
You may have noticed, the energy equation that describes the difference in superpositioned geometry ~

4bc63e4e634c26509e7e99410670e95d.gif 07ac2da3f24293a98855b310ffcf6b51.gif

Shares the difference between two expectation values of the system:

78c8de25b055f4c068bdf88afe10604f.gif5d9874bae08ec33938058826ad84cc99.gifbf59daaeba88e7a9d3e0a40712a234ec.gif

That coefficient of 93b05c90d14a117ba52da1d743a43ab1.gif may indeed attach to that energy, just like a kinetic energy term. So really, when you saw this object: cd70c68b0535ba250cec8cb5222ec6f6.gif as we have shown, we had already calculated this identity very early on in the work. So the energy equation is compatible in a Cauchy-Schwarz interpretation of spacetime.
« Last Edit: 13/09/2017 08:07:28 by Dubbelosix »
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Offline Dubbelosix (OP)

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Re: On Ideas towards a Quantum Theory of Gravity
« Reply #29 on: 15/09/2017 11:52:53 »
How to Vary the Expectation

In terms of a Laplacian, it was possible to construct an equation of the form: Again, some of these equations have been pulled out of their code because of site sensitivity to Dirac notation.


981b3799cca50b4e3cfb4598ced3919f.gif


which does not have a squared value for the Laplacian 7081e0dddb3c5b4520be9297cdd88781.gif. The funny thing is ... again, it all led to the same end anyway. Notice though, even if it was a Laplacian, you would not be squaring the Laplacian because dimensionally, that makes no sense. You could square the nabla operator and argue the wrong notation was used, but since the same notation crops up all over the internet, I must still assume it is a gap in my knowledge.

(\Delta A)^2 = <\psi| A^2| \psi> - 2<A^2> + <A^2> = <A^2> - <A^2>


You can see the equivalent of equation 2. in the quote as


<A> = \sum_n <\psi | a_n > <a_n|\psi> a_n

 = \sum_n <\psi | A | a_n><a_n|\psi > = <\psi| A (\sum_n |a_n ><a_n|) a_n |\psi> = < \psi| A |\psi>


Which makes use of the completeness theorem. To find the alternative version, you square and solve from the form involving eigenstates: Using their notation ~

(\Delta A)^2 = \sum_n <\psi | a_n > <a_n|\psi> ( a_n - <A>)^2

= \sum_n < \psi | a_n><a_n |\psi>(a^2 - 2a_n<A> + <A>^2)

= \sum_n <\psi| a_n> <a_n |\psi> a^2_n - 2<A>\sum_n <\psi |a_n><a_n| \psi> a_n + <A>^2 \sum_n <\psi|a_n> <a_n |\psi>

So that's how those strange extra symbols come into the game, even though they were never implied in the formulation of our Cauchy Schwarz spacetime.

Right... back to the work.

How do you vary the expectation value in the equation

640da99330ae1eaf7d45a941baff9e64.gif

The total variation will split this part up

93825c468c36e793ab0f649d6ac30358.gif

into

5f5611c0a76ac7e06d048cb10875ca3b.gifcdf96487e06c148f341b5056f3dd2279.gif

where the subscript of 5571a4ad52b9e896a4755316a9739053.gif denotes a ''two particle system.''
« Last Edit: 15/09/2017 14:23:00 by Dubbelosix »
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Re: On Ideas towards a Quantum Theory of Gravity
« Reply #30 on: 15/09/2017 12:26:55 »
Quote from: Dubbelosix on 15/09/2017 11:52:53
...

5f5611c0a76ac7e06d048cb10875ca3b.gifcdf96487e06c148f341b5056f3dd2279.gif

where the subscript of 5571a4ad52b9e896a4755316a9739053.gif denotes a ''two particle system.''

Take careful note though, this last equation is only for one variation in one such term for the expectation e449bb672b251ecac51a212283a3e086.gif - so you will end up with a four component equation in a superpositioned system of two particles or by calculating the binding energy, which also invites the differenece of two expectations.
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Re: On Ideas towards a Quantum Theory of Gravity
« Reply #31 on: 15/09/2017 12:34:21 »
The eigenstate approach gave rise to two extra terms, and we explained why above.

But now the reference, or you won't know what the hell I am talking about.

http://physics.mq.edu.au/~jcresser/Phys301/Chapters/Chapter14.pdf

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Re: On Ideas towards a Quantum Theory of Gravity
« Reply #32 on: 16/09/2017 00:19:16 »
A little note. It's also possible to normalize the variation by the square of the wave function


5f5611c0a76ac7e06d048cb10875ca3b.gif3f35b4776460694086069200a78ab459.gif


The reason why we would want to do this is because it would make the expectation independent of the normalization of the wave function. Also expect there to be a variation in curvature tensor on the right hand side. The variation could possible be written in the following way 5dd3d300ab6fe0e2d36dcda4d257db0a.gif.



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Re: On Ideas towards a Quantum Theory of Gravity
« Reply #33 on: 17/09/2017 19:27:54 »
Quote from: Dubbelosix on 15/09/2017 11:52:53

Right... back to the work.

How do you vary the expectation value in the equation

640da99330ae1eaf7d45a941baff9e64.gif

The total variation will split this part up

93825c468c36e793ab0f649d6ac30358.gif

into

5f5611c0a76ac7e06d048cb10875ca3b.gifcdf96487e06c148f341b5056f3dd2279.gif

where the subscript of 5571a4ad52b9e896a4755316a9739053.gif denotes a ''two particle system.''

Let's construct the full equation now. Expand the equation a bit on the right hand side and setting 8581ce2951c9474c6596dc03abbb056d.gif and also taking 64af3d8ef671708bd45dcdc96f94b1cd.gif as 4a7400461db8a0760e6ad857b3aba763.gif, which seems to be a common practice,

534c28c1fd44574dc8533f26bf21e372.gifc7cff57d5b071c29a3c1d27b969b33e1.gif

When you vary the wave function for each term, you get the full equation

d1ba3552133eee633580ddd1024478e9.gif5ca5afd75bb4815b501aa24f2f0240ac.gif

(again, devoid of Dirac notation due to site sensitivity to latex).

Even though we think about 5571a4ad52b9e896a4755316a9739053.gif as some differential change between two particle systems, in the context of the right handside, its actually the difference between two geometries of two particles - previous to the collapse state, that one particle is smeared though space. This has been the context of our investigations and how to view gravity.
« Last Edit: 17/09/2017 20:19:39 by Dubbelosix »
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Re: On Ideas towards a Quantum Theory of Gravity
« Reply #34 on: 19/09/2017 02:26:31 »
Quote from: Dubbelosix on 30/08/2017 13:55:51
Not sure if all these equations will show, the place seems sensitive to certain latex equations. If it doesn't work, I will take it out of its latex code so you can translate it.


To give a hint in how to do this unification attempt, we have three key equations,

1.

656f9de622d59d0f5b597fb7f15aa590.gif

These are the exact Christoffel symbols of the antisymmetric tensor indices c6a107300a285e5c9da6797a614c1882.gif.

2.

a366e4f4a8ac550d2faa1dfbd5493002.gif

This was an equation derived by another author, finding the relationship in a different form argued from quantum mechanics. As you will see in key equation 3. the form has similarities to application of a Hilbert space ~

3.

\sqrt{|<\Delta X_A^2>< \Delta X_B^2>|} \geq \frac{1}{2} i(< \psi|X_AX_B|\psi > + <\psi|X_BX_A|\psi>) = \frac{1}{2} <\psi|[X_A,X_B]|\psi>

Again, this is a Hilbert spacetime commutation relationship of operators which has to translate into the gravitational dynamics dictated by key equation 1.

So let's put it altogether, its just like a jigsaw puzzle now. Implemented the Christoffel symbols in approach 1. into approach 2. we get

969b494292f4578a8ee1bc2588dcf28c.gif

In the framework of the Hilbert space it becomes - assuming everything has been done correct, takes the appearance of ~


\sqrt{|<\nabla_i^2>< \nabla_j^2>|} \geq = \frac{1}{2} i(< \psi|\nabla_i\nabla_j|\psi > + <\psi|\nabla_j\nabla_i|\psi>) = \frac{1}{2} <\psi|[\nabla_i,\nabla_j]|\psi> = \frac{1}{2} <\psi | R_{ij}| \psi > = \frac{1}{2} < \psi |- [\partial_j, \Gamma_i] + [\partial_i, \Gamma_j] + [\Gamma_i, \Gamma_j]| \psi >


without imaginary number on c6a107300a285e5c9da6797a614c1882.gif

I was told by my friend my Hilbert space would be infinitely dimensional, I don't think this is the case at all, after more studying. The L^2 function implies finite results in the Hilbert space and L^2 space has functions which satisfy Cauchy Schwarz inequality. Since we formulated a spacetime theory using the Cauchy Schwarz inequality, it seems reasonable to assume this is finite dimensional.


http://mathworld.wolfram.com/L2-Space.html
 
« Last Edit: 19/09/2017 02:29:36 by Dubbelosix »
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