An hypothesis about the nature of dark energy

[Klaynos]

1 hour ago, MarkE said:

really exists

Could you please define exists in this context? And then explain how you can conclusively test for what meets that definition and what doesn't?

 

47 minutes ago, MarkE said:

I'm not a particle physicist, but I really would like to understand what mass is as a non particle physicist. I'd like to understand it as intuitively as possible. Could you recommend a book/youtube video/anything to take a first step in order to understand what mass really is? (Hopefully without too much maths).

I'm sorry, but why should you be able to understand something that takes very clever people decades to understand with some introductory texts?

If you're serious about this then the first step is a mathematical education, then a physics education. Most clever people take about 10 years of full time study before starting to understand (although many think they're there much earlier). 

[swansont]

1 hour ago, MarkE said:

Then why do all BHs shape different types of galaxies? They all seem to have different structures, such as spiral galaxies like our own, the sombrero galaxy and the pinwheel galaxy. Compare that to galaxies with no structure at all, such as irregular/peculiar galaxies, and thus aren't behaving all in the same way.

How is that attributable to the BH, rather than the stuff around the BH and the conditions of formation? 

1 hour ago, MarkE said:

 If mass can be converted into energy, then they have to be two distinct phenomena, because otherwise there wouldn’t be any conversion involved. 

Like potential energy a different phenomenon from kinetic energy? And yet they are both energy, and one can be converted to the other.

IOW, why is this a problem?

1 hour ago, MarkE said:

Not all energy has mass (such as photons and gluons), so why are we allowed to make the conclusion that all mass has to be energy already, and thus has to be moving (since no energy is sedentary).

Einstein derived E = mc^2 (for a stationary mass); that derivation and subsequent experimental confirmation is why we are allowed to make that conclusion.

Of course mass can be sedentary. In its own frame, it is at rest.

1 hour ago, MarkE said:

It can be converted, yes, but that’s the conversion of potential energy, not energy by itself.

Potential energy is one category of energy.

1 hour ago, MarkE said:

 Mass is not the same thing as energy, in fact, it's the exact opposite.

Physics disagrees with you.

1 hour ago, MarkE said:

 You can't create particles with energy you already possess, because where does this initial energy coming from?

Those are two separate issues. Of course you can create particles with energy you already possess. We have seen many examples of it.

 

[Mordred]

5 minutes ago, Klaynos said:

 

I'm sorry, but why should you be able to understand something that takes very clever people decades to understand with some introductory texts?

If you're serious about this then the first step is a mathematical education, then a physics education. Most clever people take about 10 years of full time study before starting to understand (although many think they're there much earlier). 

lol even after 30 years of study I still find the Yukawa couplings involvement in the Higgs field weak symmetry gauge frustrating to determine the mass of the gauge bosons. There is no truly easy shortcuts to understand how mass arises from coupling constants.

[Klaynos]

1 minute ago, Mordred said:

lol even after 30 years of study I still find the Yukawa couplings involvement in the Higgs field weak symmetry gauge frustrating to determine the mass of the gauge bosons. There is no truly easy shortcuts to understand how mass arises from coupling constants.

Exactly. If it was easy everyone (or at least a large subset) would already know the answers. 

[Strange]

1 hour ago, MarkE said:

I'm not a particle physicist, but I really would like to understand what mass is as a non particle physicist.

There are two really intuitive approaches to mass (and sorry if they seem rather obvious):

One is inertia, or resistance to movement. This is captured by Newton's f=ma; in other words, if an object has more mass then we have to use correspondingly more force to accelerate it by the same amount.

The other is what we perceive as "weight"; ie. the amount that something responds to gravity. Newton (again!) described this as a force between things that was proportional to their masses (in a similar way to the force between objects with a electric charge). He didn't attempt to say what the cause of this force was. Einstein described this as the effect of mass (or energy, or a few other things) on the geometry of space and time.

The interesting thing is that these two concepts of mass are equivalent. The heavier something is, the harder it is to move. It's not really clear why this should be the case (but, ultimately, it isn't clear why mass or electric charge or anything else is the way it is). But their equivalence led Einstein to point out that acceleration and gravity are indistinguishable: if you were in a sealed room, you would not be able to tell if you were on the Earth'ssurface or accelerating through empty space at 1g.

The other links and videos will give more background on that.

[Mordred]

1 hour ago, Klaynos said:

Exactly. If it was easy everyone (or at least a large subset) would already know the answers. 

Here is a demonstration of the complexity.

start with the Higgs field which is a weak isospin doublet with 4 components

[latex]\phi=\begin{pmatrix}\phi^2\\\phi^-\end{pmatrix}=\frac{1}{\sqrt{2}}\begin{pmatrix}\phi_1&i\phi_2\\\phi_3&i\phi_4\end{pmatrix}[/latex]

a fluctuation around the minimal of the Mexican hat potential defined by the vacuum expectation value [latex]v=\frac{|\mu|}{\sqrt{\lambda}}=\frac{2M_w}{g}=246 Gev[/latex]

which defines the electroweak scale. Choose thedirection fluctuation so that

[latex]\phi_0=\frac{1}{2}\begin{pmatrix}0\\v\end{pmatrix}[/latex]

the fluctuation around the minimum of the Mexican hat potential v is written as

[latex]\phi(x)=\phi_0+h(x)[/latex] where [latex]\phi=\begin{pmatrix}\phi^+\\\phi^-\end{pmatrix}=\frac{1}{\sqrt{2}}\begin{pmatrix}\phi_1&i\phi_2\\\phi_3&i\phi_4\end{pmatrix}[/latex][latex]\Rightarrow\frac{1}{\sqrt{2}}\begin{pmatrix}0\\v+h(x)\end{pmatrix}[/latex]

where h(x) is the Higgs boson.

expand the Higg's potential to second order

[latex]V=V_0+\frac{\mu^2}{2}(2Vh+h^2)+\frac{\lambda}{4}(4v^3h+6v^2h^2)=V_0+\lambda v^2h^2[/latex]

the additional term from [latex]h^2[/latex] gives the Higgs boson its mass term.

[latex] M^2_H=2\lambda v^2  M_H=\sqrt{2}|\mu|[/latex]

see how complex the coupling is just for the Higg's boson self field coupling. Very few people will understand the mth but in essence the above describes the Higg's bosons self coupling to the scalar Higgs field of the vacuum expectation value minimal to arrive at the bosons mass term.

Now the electroweak mass terms involves several further steps to couple the Higgs field [latex]\phi^2[/latex] to the W+,W-,Z bosons.

without going through all the steps we have two additional coupling constants g and [latex] \acute{g}[/latex] these arise from

  [latex] (\frac{g}{2}\vec{\tau}\bullet\vec{W}+\frac{\acute{g}}{2}B)\phi_0[/latex]

there is several lengthy and difficult to latex steps involved but one will arrive at these two very useful equations. (the above took me nearly 1 hour to get correct lmao

[latex]{M_W}=\frac{mg}{2}[/latex] which gives the mass to the W+ and W- bosons and [latex] M_Z=\frac{v\sqrt{g^2+\acute{g}}^2}{2}[/latex] which is the mass for the Z boson.

Not so easy to relate to but in order to understand how these apply to kinematics one must look into the Langrene and Hamilton's of action.

anyways I missed numerous steps but here is a more complete work up

http://www.theorie.physik.uni-muenchen.de/lsfrey/teaching/archiv/sose_09/rng/higgs_mechanism.pdf

it should be sufficient to demonstrate how field couplings can give rise to the mass terms involved.

If I recall correctly Matt Roose "Introductory to cosmology" has a more easy to follow workup but \I will have to check that later on...soon as I find my copy lol hopefully there isn't too many mistakes in the above my handwriting is atrocious to read my own notes.

edit side note equations on 36 in particular [latex]A_\mu[/latex] defines the coupling or lack of to photon qauge boson

You will note I specifically chose an article prior to Higgs boson discovery to demonstrate how the mass estimates came about. A large part of the reason earlier papers were off on Higg's boson mass terms has to do with uncertainties inherent in the neutrino masses at the time period and the involved mixing angles

 

 

 

 

 

 

Edited June 6, 2018 by Mordred

[MarkE]

Thanks for all your comments, and for the links and information that you’ve provided! I’m going to do some research on my own before I ask questions regarding this subject on this forum. Goal: to understand why only an energetic particle could be responsible for any mass (such as dark matter or a black hole), and why there’s no such thing as the ‘physics of nothingness’, describing the attractive force towards particles from some kind of ‘hole’ in spacetime. I’ll keep you updated!

P.S. Thanks for these Higgs field equations, Mordred, I think I'm actually able to read and understand them .

Edited June 8, 2018 by MarkE

[beecee]

6 hours ago, MarkE said:

Thanks for all your comments, and for the links and information that you’ve provided! I’m going to do some research on my own before I ask questions regarding this subject on this forum. Goal: to understand why only an energetic particle could be responsible for any mass (such as dark matter or a black hole), and why there’s no such thing as the ‘physics of nothingness’, describing the attractive force towards particles from some kind of ‘hole’ in spacetime. I’ll keep you updated!

P.S. Thanks for these Higgs field equations, Mordred, I think I'm actually able to read and understand them .

Quite admirable seriously,  re your potential research on the subject, but first make sure you are completely familiar with the state of current particle physics and the reasons and data that is currently available.