New mass creation

[Mordred]

You have otherwise I would have corrected it. The paper shows both conserved and not conserved metrics..

 

The author in this case supports the latter case. Keep in mind there are different views on the subject.

 

Also note the FLRW metric hasn't particularly incorporated the Higgs field as the Higgs needs further study. ( in particular the Mexican hat potential) technical name metastability.

Edited February 24, 2016 by Mordred

[David Levy]

After a brief overview in the following article:

 

http://arxiv.org/ftp/arxiv/papers/0810/0810.1629.pdf

 

it is stated:

"We find that though both propositions appeal to the Friedmann equations for validity, an increasing mass with increasing radius is more in harmony with the thermal history of the big bang model"

 

However, with regards to Friedmann equations:

https://en.wikipedia.org/wiki/Friedmann_equations

 

"The Friedmann equations start with the simplifying assumption that the universe is spatially homogeneous and isotropic, i.e. thecosmological principle; empirically, this is justified on scales larger than ~100 Mpc."

 

Therefore, it was quite clear to me that we can't use Friedmann equations for a Universe which is smaller than ~100 Mpc. Hence, technically we shouldn't use those equations for early universe.(As the Early Universe was not homogeneous and isotropic due to its limited size).

Surprisingly, in the article they are using Friedmann equations for early universe, as it is stated:

"Equation (19) is the equation for the thermal history of the universe during the radiationdominated era whether flat, open or closed.

If we assume a negligible Λ and that the curvature term, kc2 /R2 is zero or negligibly positive or negative in the early universe, then taking the square root of Eq.(19) gives us"

T2 = √(3c2 /8πGa) X 1/t

Hence, my question is as follow:

How could it be that they science is using Friedmann equations for the calculation of early Universe, while it is clearly stated that those questions had been developed for a Universe which is bigger than ~100 Mpc (due to homogeneous and isotropic requirements)?

[MigL]

IIRC in GR energy conservation is analyzed by considering a bounded area of space-time and examining the energy flux in/out of the boundary.

This is obviously only possible locally. The global option does not exist since there is no boundary.

So the model, GR, has this 'deficiency'' incorporated into it.

 

Is it any wonder that Big Bang Theory, based also on this GR model, has the same 'deficiency' ?

 

Personally I will go on believing that energy conservation holds.

We just don't have a handle on it yet.

[Mordred]

The 100 Mpc size is the size where the Universe is roughly homogeneous and isotropic. As you contract the Universe the scale needed becomes smaller as well. For example conditions at CMB is extremely homogeneous and isotropic in temperature/mass distribution.

 

At the Planck epock everything is in a condition called thermal equilibrium. The size then was small enough that you don't require the curvature constant.

 

This point in time you can't distinquish any anisotropy so it's homogeneous and isotropic at any scale. This will continue for the majority of the radiation dominant era.

 

Particularly since the rapid expansion of inflation has a supercooling effect, but on the slow roll cycle a super reheating effect.

 

Any anistropies is essentially washed out to an extremely uniform distribution.

 

Anisotropy development start somewhat later.

 

So yes the FLRW is particularly useful prior to CMB.

Edited February 24, 2016 by Mordred

[David Levy]

Well,

 

Mr. Friedmann had developed his equations for a Universe which is bigger than ~100 Mpc.

I'm not sure that he had considered that one day his equations will be used for Early Universe.

 

Somehow, I get lost with all the assumptions.

For example, at the plank epock,

 

At the Planck epock everything is in a condition called thermal equilibrium. The size then was small enough that you don't require the curvature constant.

 

At that time, the expected value of R (Radius) should be almost Zero.

So, it's quite clear that the value of: kc2 /R2 should be infinite (if R =0) or at least high enough (so, for sure, we can't assume that it is zero or neglected value).

 

Unfortunately, in the article they have assumed that this value is zero for early universe:

"kc2 /R2 is zero or negligibly positive or negative in the early universe".

 

However, if you claim that it is O.K. - than it is O.K. for me.

Now, with regards to the new mass creation:

 

It is stated:

 

"We find that though both propositions appeal to the Friedmann equations for validity, an increasing mass with increasing radius is more in harmony with the thermal history of the big bang model."

"We conclude that the universe has been increasing in mass and radius in obedience to the energy conservation law."

 

So, if I understand it correctly, they claim that the Universe is increasing its mass as it expands.

But, what is the source for this new mass creation? Where it comes from and how?

Edited February 24, 2016 by David Levy

[Mordred]

Note he stated in that quote " in obedience to the conservation of energy"

 

I believe what you need to look at is "what is mass"

 

The definition of mass is resistance to inertia.

 

However different types of mass exist. GR doesn't have a clear cut definition of total mass. It doesn't even have a clear cut conservation of energy or mass.

 

"Generalizing this definition to general relativity, however, is problematic; in fact, it turns out to be impossible to find a general definition for a system's total mass (or energy). The main reason for this is that "gravitational field energy" is not a part of the energymomentum tensor"

 

https://en.m.wikipedia.org/wiki/Mass_in_general_relativity

 

The problem is that The paper uses the FLRW metric, which is based on GR.

 

Observer viewpoints can alter how one measures mass or energy, so when one calculates the total mass of the system, you use an observer. Fundamental observer in the FLRW metric.

 

On that link there is a reference to ADM mass. (Which that paper never mentioned.)

 

https://en.m.wikipedia.org/wiki/ADM_formalism#ADM_energy

 

"According to general relativity, the conservation law for the total energy does not hold in more general, time-dependent backgrounds for example, it is completely violated in physical cosmology. Cosmic inflation in particular is able to produce energy (and mass) from "nothing" because the vacuum energy density is roughly constant, but the volume of the Universe grows exponentially."

 

You can see the difficulty on the conservation of energy/mass.

 

How you define and measure the system can vary the results.

 

Suffice it to say conservation of mass or energy of the universe is a question without a clear answer.

 

This doesn't imply were creating mass/energy when you get right down to it the problem is we can't properly define the conservation of mass/energy for all observer situations in an evolving spacetime.

IIRC in GR energy conservation is analyzed by considering a bounded area of space-time and examining the energy flux in/out of the boundary.

This is obviously only possible locally. The global option does not exist since there is no boundary.

So the model, GR, has this 'deficiency'' incorporated into it.

 

Is it any wonder that Big Bang Theory, based also on this GR model, has the same 'deficiency' ?

 

Personally I will go on believing that energy conservation holds.

We just don't have a handle on it yet.

This is in my opinion a good description of the problem

PS don't worry if this is all confusing. This type of problem can make a professor in philosophy of cosmology head spin.

Edited February 24, 2016 by Mordred

[EdEarl]

Dark energy appears to be increasing with the Universe expansion. I realize there is no evidence, but there are some interesting observations. Vacuum energy makes particle-antiparticle pairs; then they annihilate quickly. But, what happened to all the antimatter in the Universe. Why wouldn't it still be disappearing or not being made. Maybe dark energy and vacuum energy are not the same, but it is easy to imagine dark energy contributing to vacuum energy.

[Mordred]

Dynamically the two are both modelled as a scalar field. So is the Higgs field.

 

The equation of state that is used is

 

[latex]w = \frac{\frac{1}{2}\dot{\phi}^2 - V(\phi)}{\frac{1}{2}\dot{\phi}^2 + V(\phi)}[/latex]

 

In the case of the cosmological constant w=-1.

 

This in thermodynamics equates to an incompressable fluid with a vanishing kinetic energy.

 

quantum fluctuations via the Heisenberg uncertainty principles and zero point energy which is the theoretical lowest energy state

 

[latex]e=\frac{\hbar v}{2}[/latex] was at one time proposed to the cosmological constant. However calculations later showed this lead to an error of 120 orders of magnitude too much energy.

 

We're still trying to solve baryogenises on why our universe is currently comprised of matter vs antimatter balance.

 

There is some hope in the SO(10) supersymmetric models but only time will tell.

!

Moderator Note

I see no reason as to why this thread should remain in the speculations forum. The OP is asking legitimate questions concerning a fundamental problem in Cosmology in terms of the conservation laws.

 

At no point in the discussion has a single speculative argument been raised. Rather it's clear the OP is asking for information relating to the topic.

The information within this thread is better suited in the Astronomy and Cosmology forum.

 

For these reasons I'm going to move the thread where it belongs.

Edited February 25, 2016 by Mordred

[David Levy]

Dark energy appears to be increasing with the Universe expansion. I realize there is no evidence, but there are some interesting observations. Vacuum energy makes particle-antiparticle pairs; then they annihilate quickly. But, what happened to all the antimatter in the Universe. Why wouldn't it still be disappearing or not being made. Maybe dark energy and vacuum energy are not the same, but it is easy to imagine dark energy contributing to vacuum energy.

 

In order to keep the balance in the Universe, there must be a specific ratio between dark energy, mass and dark mass.

Therefore, if there is any increase in the dark energy, it should set a relative increase in the mass and dark mass.

Do you agree with this statement?

[swansont]

In order to keep the balance in the Universe, there must be a specific ratio between dark energy, mass and dark mass.

 

 

What balance? It's not obvious to me that this is a true statement. Do you have a citation?

[EdEarl]

 

 

What balance? It's not obvious to me that this is a true statement. Do you have a citation?

David, I'm not well read enough to know of any balance. The expanding Universe is expected to reduce the mass density; does the balance you mentioned keep the mass density constant?

Edited February 25, 2016 by EdEarl

[David Levy]

What balance?

 

The balance between the following elements:

Dark energy contributes 68.3%

Dark matter contributes 26.8%

Ordinary (baryonic) matter contribute 4.9%

https://en.wikipedia.org/wiki/Dark_energy

"..that dark energy contributes 68.3% of the total energy in the present-day observable universe. The mass–energy of dark matter and ordinary (baryonic) matter contribute 26.8% and 4.9%, respectively, and other components such as neutrinos and photons contribute a very small amount"

Therefore, if there is an increase in the dark energy, (without a relative increase in the dark matter or ordinary matter), than in the long run it could change the ratio between those three elements.

Hence, I was wondering how important it is for the Universe to keep this ratio.

Edited February 26, 2016 by David Levy

[David Levy]

In any case, as it is stated:

Dark energy appears to be increasing with the Universe expansion.

 

If that is correct;

What could be the source for this extra Dark Energy?

Is it due to a new energy creation?

If yes, than it could violet the Energy Conservation.

In order to keep the Energy Conservation, this extra dark energy should comes out of the total available energy in the Universe.

So, does it mean that some of the dark mass or ordinary mass have been transformed to Dark Energy?

Edited February 26, 2016 by David Levy

[swansont]

Hence, I was wondering how important it is for the Universe to keep this ratio.

 

 

Earlier you were insisting that it must always be the same. Which is it? Do you have a citation that says this, or not?

[David Levy]

Earlier you were insisting that it must always be the same.

 

Sorry, it seems that I didn't introduce it correctly.

If there is a new extra dark energy, than in order to keep the Energy Conservation, it should come out of the total available energy in the Universe.

Therefore, I have assumed that over time there might be a change in the ratio between Dark energy, Dark mass and Ordinary mass.

 

However, with regards to the paradox which is:

1. The cosmologic constant must be constant

2. The Total Energy of the Universe must be constant

 

Normally, paradox is a clear indication for an error.

So, why do we insist to find an explanation for this paradox, instead of reverify the basic elements which leads us to that error?

Could it be that we have missed something critical?

Is there any chance that we have made an error in our equations, calculations, assumptions, constants, initial conditions..?

Edited February 27, 2016 by David Levy

[David Levy]

I have just found an interesting article.

 

It seems that they try to set a new calculation by "..studying the quantum correction terms in the second order Friedmann equation"

 

http://www.sciencedirect.com/science/article/pii/S0370269314009381#

 

"It was shown recently that replacing classical geodesics with quantal (Bohmian) trajectories gives rise to a quantum corrected Raychaudhuri equation (QRE). In this article we derive the second order Friedmann equations from the QRE, and show that this also contains a couple of quantum correction terms, the first of which can be interpreted as cosmological constant (and gives a correct estimate of its observed value), while the second as a radiation term in the early universe, which gets rid of the big-bang singularity and predicts an infinite age of our universe."

 

Is it a real article or some sort of speculation?

Edited February 27, 2016 by David Levy