Dark Matter

[Quantum321]

I have no idea what dark matter is. Hopefully, through a meaningful exchange of ideas we can make some sense of this. It is estimated that approximately, 27% of the known universe is dark matter. Dark matter because it can't be observed and does not interact with electromagnetic energy.

Its logical to assume that all of particles from the BB are still in our universe. Some visible and some are not visible. Therefore, I think dark matter has been part of the universe all along and is not some undiscovered particle outside the standard model. I understand the LHC has completed its two year retrofit and is now more powerful than before. Perhaps they can confirm or debunk supersymmetry and possible find that particle that is dark matter. Personally, since dark matter is 27% of the universe I would think we would have discovered it by now.

So why am I posting about dark matter? I watched a very interesting science program and learned that 90% of the matter in our solar system lays outside of Pluto the dwarf planet. 90%?? Are you kidding. This is one reason I think dark matter is made of some of the particles from the BB.

[mathematic]

Dark matter arose from the big bang. No one disputes that. The part of the solar system past Pluto has nothing to do with it.

[Quantum321]

My reasoning here is if 90% of the matter in our solar system wasn't detected until recently ie we could not see it, perhaps that's what's going on with dark matter. It may be the universe is full of the same matter and we just can't see it because it may be too small to detect.

[Janus]

I have no idea what dark matter is. Hopefully, through a meaningful exchange of ideas we can make some sense of this. It is estimated that approximately, 27% of the known universe is dark matter. Dark matter because it can't be observed and does not interact with electromagnetic energy.

Its logical to assume that all of particles from the BB are still in our universe. Some visible and some are not visible. Therefore, I think dark matter has been part of the universe all along and is not some undiscovered particle outside the standard model. I understand the LHC has completed its two year retrofit and is now more powerful than before. Perhaps they can confirm or debunk supersymmetry and possible find that particle that is dark matter. Personally, since dark matter is 27% of the universe I would think we would have discovered it by now.

So why am I posting about dark matter? I watched a very interesting science program and learned that 90% of the matter in our solar system lays outside of Pluto the dwarf planet. 90%?? Are you kidding. This is one reason I think dark matter is made of some of the particles from the BB.

I'm pretty sure that the 90% figure does not include the mass of the Sun. In other words, if you don't count the Sun, then you might end up with 90% of the mass being further away than Pluto (the Sun still contains the vast majority of the mass of the Solar system as a whole). This shouldn't be surprising, as the farther you move outward, the more room you have to fit matter. The volume included in the area from Pluto's orbit out to three times is distance has 8 times the volume of that region inside Pluto's orbit. And you also have to realize that the region inside Pluto's orbit is not all that crowded. If you were to take all of it (planets, moons etc.) and evenly spread it around in that volume, you would end up with a density ~1/400,000,000 of that of air at sea level.

My reasoning here is if 90% of the matter in our solar system wasn't detected until recently ie we could not see it, perhaps that's what's going on with dark matter. It may be the universe is full of the same matter and we just can't see it because it may be too small to detect.

One of the reasons that this doesn't work is that you would have to assume that that matter was there all the time from the beginning, and if you do that, nucleosynthesis during the early ages of the universe would have produced a much different universe than what we see. We wouldn't have the universe we have now if it contained enough regular matter to account for dark matter.

[Quantum321]

"One of the reasons that this doesn't work is that you would have to assume that that matter was there all the time from the beginning, and if you do that, nucleosynthesis during the early ages of the universe would have produced a much different universe than what we see."

That is my original premise, that dark matter is part of all the particles produced by the BB. To assume otherwise begs the question is dark matter is from another universe?

What does fit my original premise are brown dwarfs. In fact some think there may be brown dwarf's in our solar system.

[Mordred]

One of the leading possibilities for dark matter is possibly sterile neutrinos. This derives from the Higg's metastability on the seesaw Mexican hat potential.

 

here is some papers on it. We still need further research but the potential is there.

 

DARK MATTER AS STERILE NEUTRINOS

 

http://arxiv.org/abs/1402.4119

http://arxiv.org/abs/1402.2301

http://arxiv.org/abs/1306.4954

 

One advantage is that neutrinos have many of the same characteristics of DM in also being weakly interactive.

 

The first two articles deal with possible detection following the predicted indirect influence from the last paper. The last paper discusses the possible identity.

 

The problem isn't necessarily size for detection. The only known properties of DM is it couples to gravity and the weak force. It doesn't interact with the electromagnetic nor strong force.

 

But then neither do neutrinos.

 

Yes you are correct that dark matter drops out of thermal equilibrium at an early stage in our universes development. Evidence shows DM as a key ingrediant for the Early large scale structure formation.

 

Earliest estimates I've seen are as low as 10-32 seconds after BB. Prior to that the temperature is considered too high. Even for neutrinos.

Edited November 17, 2016 by Mordred

[Quantum321]

Resident Expert, did you see this? http://www.symmetrymagazine.org/article/sterile-neutrinos-in-trouble

 

“The sterile neutrino would’ve been a profound discovery,” says physicist Ben Jones of the University of Texas, Arlington, who worked on the IceCube analysis. “It would really have been the first particle discovered beyond the Standard Model of particle physics.”

It’s surprising that such a result would come from IceCube. The detector, buried in about a square kilometer of Antarctic ice, was constructed to study very different neutrinos: high-energy ones propelled toward Earth by violent events in space. But by an accident of nature, IceCube happens to be in just the right position to study low-mass sterile neutrinos as well.

There are three known types of neutrinos: electron neutrinos, muon neutrinos and tau neutrinos. Scientists have caught all three types, but they have never built a detector that could catch a sterile neutrino.

Neutrinos are shape-shifters; as they travel, they change from one type to another. The likelihood that a neutrino has shifted to a new type at any given point depends on its mass and the distance it has traveled.

It also depends on what the neutrino has traveled through. Neutrinos very rarely interact with other matter, so they can travel through the entire Earth without hitting any obstacles. But they are affected by all of the electrons in the Earth’s atoms along the way.

“The Earth acts like an amplifier,” says physicist Carlos Argüelles of MIT, who worked on the IceCube analysis.

Traveling through that density of electrons raises the likelihood that a neutrino will change into the predicted sterile neutrino quite significantly—to almost 100 percent, Argüelles says. At a specific energy, the scientists on IceCube should have noticed a mass disappearance of neutrinos as they shifted identities into particles they could not see.

“The position of the dip [in the number of neutrinos found] depends on the mass of sterile neutrinos,” says theorist Joachim Kopp of the Johannes Gutenberg University Mainz. “If they were heavier, the dip would move to a higher energy, a disadvantage for IceCube. At a lower mass, it would move to a lower energy, at which IceCube cannot see neutrinos anymore. IceCube happens to be in a sweet spot.”

And yet, the scientists found no such dip.

This doesn’t mean they can completely rule out the existence of low-mass sterile neutrinos, Jones says. “But it’s also true to say that the likelihood that a sterile neutrino exists is now the lowest it has ever been before.”

[Mordred]

Will you quit with this "Resident expert" bit. I do have a callsign please use it.

 

I can quarantee research hadn't stopped on sterile neutrinos candidate for dark matter despite that link you posted. I also specified its one possibility.

In point of detail here is a 256 page coverage written in Feb 2016.

 

There is some key details you need on the link you provided. I will detail this at the end.

 

http://www.google.ca/url?sa=t&source=web&cd=2&ved=0ahUKEwj62oSPgK_QAhXIjlQKHertC68QFggdMAE&url=https%3A%2F%2Farxiv.org%2Fpdf%2F1602.04816&usg=AFQjCNFWEv0XhB7y8PFxMsgnsWZdQb4JzQ

 

Make your own opinion there is still validity in the possibility. The possibility has not been ruled out yet.

 

By the way the sterile neutrino possibility doesn't require supersymmetry. Although SO (10) MSSM is the strongest support for the sterile neutrino theory.

 

The model is also possible under SO (10) MSM. Though its incredibly difficult to find the minimal symmetric standard model variations. reference 181, 182 of that link.

 

Don't let pop media articles fool you. Study the model itself and make a self informed opinion. We can exchange counter papers all day long and not change each others opinion.

 

For example there is several possible types of sterile Neutrinos. eV scale, KeV scale and MeV scale. The paper I posted discusses all three but supports the KeV scale.

 

The low mass reference in that link you provided is the eV scale specifically. You don't see these details from the pop media literature.

 

Here under the full paper is the specification "light sterile neutrino" which is in the eV mixing range. It doesn't test the keV nor MeV mixing range.

 

Here is the details I included the paper to your link

 

" Resonant oscillations due to matter eects would produce distinctive signatures of sterile neutrinos in the large set of high energy atmospheric neutrino data recorded by the IceCube Neutrino Observatory. The IceCube collaboration has performed searches for sterile neutrinos with m2 between 0:1 and 10 eV^2. "

 

Doesn't copy paste well from the arxiv paper but here is the arxiv covering your link.

 

The test range is detailed in the conclusions. Like I said don't let pop media coverage fool you. That test only shows a less likely hood of sterile neutrinos in 0.1 to 10 eV range.

https://arxiv.org/abs/1605.01990

 

Side note that range is too short lived to be a good DM candidate. The lifetime is too short in this case. Also the eV range would make it relativistic which would be hot dark matter not cold dark matter.

 

The link I provided mentions that detail however as stated it supports the keV range as a DM candidate. Not all papers do, its one of many possible.

 

(just a side note you often see seesaw 1 and seesaw 2 but under SO (10) MSSM I've read papers discussing as high as seesaw VI.) though usually in dissertations.)

 

though that requires finding Higglets

Edited November 17, 2016 by Mordred

[Quantum321]

Sorry about that Mordred. I had no idea neutrinos could shape-change depending on the medium they travel through. You mentioned the best candidate is in the Kev range and their doesn't appear to be a suitable detector to measure that mass.

Neutrinos mass is near zero. It would take a awful of them to equal the 27% of the universe that is dark matter.

[Mordred]

Sorry about that Mordred. I had no idea neutrinos could shape-change depending on the medium they travel through. You mentioned the best candidate is in the Kev range and their doesn't appear to be a suitable detector to measure that mass.

Neutrinos mass is near zero. It would take a awful of them to equal the 27% of the universe that is dark matter.

Yes but sterile neutrinos can have higher mass. Also the Higg's metastability can cause different mass values.

 

The quantity of DM and neutrino predictions is also problematic there are solutions to that but again becomes model specific depending on the mass of the sterile neutrino.

No apology needed by the way, it takes specific research into the topic to catch all the variations and to seperate the pop media poor misleading coverage.

 

Most people don't even realize just how many variations there truly is. Even after 5 years study on this particular study I still find variants I've never encountered before.

 

I don't know if you can afford textbooks but one of the best books covering the VeV and what it means is Mukhanov's Physical foundations of Cosmology. He goes into excellent on symmetry breaking.

 

https://www.amazon.com/Physical-Foundations-Cosmology-Viatcheslav-Mukhanov/dp/0521563984

 

PS thanks for using my callsign lol I prefer that. +1 for catching some key details involved.

Edited November 17, 2016 by Mordred

[Quantum321]

Recent studies indicate Higgs is more stable than previously thought. I don't believe the Universe is metastavle. . Its been around for 13.7 billion years. With the space between galaxies expanding at a rate of a 75 kilometers per second per megaparsec how could there be a cataclysmic collapse?

[Mordred]

Well again we get into the details of false vacuum/true vacuum metastability which this all hinges upon. There is indications on both sides of the fence.

 

Part of the problem is generating the needed energy ranges to fully test the Higg's metastibility and technicolor.

 

If it helps tomorrow I should have time to post some metrics to better understand the Higg's itself. There is a particular good low math example in Ryder Lewis "Introductory to Cosmology"

 

In cosmology terms were not sure if we are in a false vacuum or true vacuum state. There is potential of another symmetry break but like you I find this unlikely as our blackbody temperature is only 2.7 k. However thats a personal opinion not a scientific one.

Edited November 17, 2016 by Mordred

[Quantum321]

That would be helpful..thanks

[Mordred]

Recent studies indicate Higgs is more stable than previously thought. I don't believe the Universe is metastavle. . Its been around for 13.7 billion years. With the space between galaxies expanding at a rate of a 75 kilometers per second per megaparsec how could there be a cataclysmic collapse?

by the way careful on Hubbles constant. Its only constant at a given time. It increases greatly in the past. At the time of the CMB its roughly 1000 times greater than today.

That would be helpful..thanks

no problem wife will be at work then lol

[Quantum321]

The whole idea that dark matter exists much more abundantly than baryonic matter (DM 27% BM 4.8%) is counter intuitive to the extreme. Some have challenge even the most cherished beliefs and suggested that various modifications of the standard laws of general relativity such as MOND, TeVes and conformal gravity would account for the observations without invoking additional matter (heresy I know) I think dark matter is actually out there.

 

Some scientists even consider dark matter to be a new kind of dynamical energy fluid or field, something that fills all of space but something whose effect on the expansion of the universe is the opposite of that of matter and normal energy. Some theorists have named this "quintessence," after the fifth element of the Greek philosophers. But, if quintessence is the answer, we still don't know what it is like, what it interacts with, or why it exists.

 

Back to the neutrino. Its one of the most abundant particles in the universe and comes in three flavors—the electron neutrino, muon neutrino and tau neutrinos and can switch flavor through a process called oscillation. This surprising fact represents a revolution in physics—the first known particle interactions that indicate physics beyond the extremely successful Standard Model. ( http://www.symmetrymagazine.org/article/february-2013/neutrinos-the-standard-model-misfits )

Whoa!! Beyond the standard model? This is getting scary.

[Strange]

The whole idea that dark matter exists much more abundantly than baryonic matter (DM 27% BM 4.8%) is counter intuitive to the extreme.

 

 

Indeed. But many things discovered by science are counter-intuitive. That is why we use science rather than "common sense".

 

 

 

Some have challenge even the most cherished beliefs and suggested that various modifications of the standard laws of general relativity such as MOND, TeVes and conformal gravity would account for the observations without invoking additional matter (heresy I know) I think dark matter is actually out there.

 

This has nothing to do with "cherished beliefs" or "heresy". It is just that those models do not, currently, match the evidence as well as dark matter being matter.

 

There is a good survey of the current state of the art in both types of model here: http://backreaction.blogspot.co.uk/2016/10/modified-gravity-vs-particle-dark.html

 

 

 

Whoa!! Beyond the standard model? This is getting scary

 

Not scary, exciting. This is what makes science so great: the possibility of new physics.

[Quantum321]

Strange..."This has nothing to do with "cherished beliefs" or "heresy". It is just that those models do not, currently, match the evidence as well as dark matter being matter."

Give me a break. Quit picking apart everything I say and injecting your opinions. While they are certainly not wrong they don't really help. Creative writing holds the readers attention.

[Strange]

Quit picking apart everything I say and injecting your opinions.

When you stop posting your personal beliefs as if they were facts, I will.

[Janus]

"One of the reasons that this doesn't work is that you would have to assume that that matter was there all the time from the beginning, and if you do that, nucleosynthesis during the early ages of the universe would have produced a much different universe than what we see."

That is my original premise, that dark matter is part of all the particles produced by the BB. To assume otherwise begs the question is dark matter is from another universe?

What does fit my original premise are brown dwarfs. In fact some think there may be brown dwarf's in our solar system.

The point is that in order for dark matter to have been here from the beginning, it could not be in the form of "normal" matter that we just don't see. Just much extra "normal" matter would have have had a much different effect on the evolution of the Universe. Thus, dark matter, while always there, cannot be made up of "normal" matter and is something else. Dark matter did have an influence on the evolution of the Universe, just not the same type of influence it would had if it consisted of baryonic matter(The stuff star, planets and we are made of). There is a limit on how much baryonic matter the universe could contain and still look like it does.

The whole idea that dark matter exists much more abundantly than baryonic matter (DM 27% BM 4.8%) is counter intuitive to the extreme.

Why? That's just your Baryo-centrism talking. You are made of baryonic matter as is the Earth, the Sun and everything else that makes up complex objects, so you are prejudiced in its favor . But why should we consider this the norm? Dark matter is simple and baryonic matter complicated. It seems to me that simple things are more likely than complex, So why wouldn't one consider dark matter as the norm and baryonic matter as the exception. It is only our ego that insists that things are the other way around. Somewhere in the back of our heads we continue to assume that the universe is here for our benefit, other than us maybe being an result of an outlying effect.

[Mordred]

OK here is some Higg's field details that will make understanding the Higg's itself simpler. Keep in mind I am using Lewis Ryder "Introductory to General Relativity" for this. You may find more recent articles with slightly different metrics. (PS this will take me some time to type in and latex)

 

First we need to nitice that there is actually 4 field quanta in electro-weak theory. [latex]\gamma, W^-, W^+, and, Z^o.[/latex] notice the second and third is an antiparticle pair.

 

Now the problem is we need a mechanism to give the neutrinos mass without giving photons mass. This is where the Higg's mechanism steps in.

To start with Peter Higg's looked at superconductivity. The defining characteristic of conductivity is that at a temperature below a critical temperature [latex]T_c[/latex] some metals lose all electrical resistance. Resistance literally becomes zero, not merely very small.

 

[latex](E=Rj) =j=\sigma E[/latex]

 

where [latex]\sigma[/latex] is the conductivity. A metal in conductivity state then exhibits a persistant current even in no field:[latex]j=\not=0[/latex] when E=0. The key to understanding superconductivity is to describe the current as supercurrent [latex]j_s[/latex]. But unlike the equation above to realize this is proportional not to E but to the vector potential A.

[latex]j_s=-k^2A[/latex] with a negative proportionality. This is the London equation.

 

The relevant property we however are seeking is the Meissner effect, which is a phenomena that the magnetic flux is expelled from superconductors.

 

Higg's then showed that suitably transformed into a relativistic theory, this is the equivalent to showing the photon has mass. (just not rest mass lol)

 

The reasoning goes as follows. First thee London equation explains the Meissner effect, for taking the curl of Amperes equation

[latex]\nabla*BB=j[/latex] gives [latex]\nabla(\nabla^2B=\nabla*j[/latex] noting that [latex]\nabla*B=0[/latex] (no magnetic monopoles) gives [latex]\nabla^2B=k^2B[/latex] which is equal to [latex]\nabla^2A=k^2A[/latex]

In one dimension the solution to this is

 

[latex]B(x)=B(0)exp(-kx)[/latex]

which describes the Meissner effect-the magnetic field is exponentially damped inside the superconductor, only penetrating to a depth of order 1/k.

 

This however is still non relativistic. To make it relativistic [latex]\nabla^2[/latex] is replaced by the Klein_Gordon operator [latex]\Box[/latex] and A by the four vector [latex]A^\mu=(\phi,A)[/latex]

 

giving

[latex](\frac{1}{c^2}\frac{\partial^2}{\partial t^2}+\frac{\partial^2}{\partial x^2}+\frac{\partial^2}{\partial y^2}+\frac{\partial^2}{\partial x^2})A^\mu=k^2A^\mu[/latex]

 

the vector potential is a field but we are currently interested in the photon, the quantum of the field. so we make the transition to quantum theory by the usual description.

[latex]\frac{\partial}{\partial t}\mapsto-\frac{i}{\hbar}E, \frac{\partial}{\partial}{\partial x}\mapsto\frac{i}{\hbar p_x}....[/latex]etc

 

giving the quantum of the field [latex]A^\mu[/latex],

[latex]E^2-p^2c^2=k^2c^2\hbar^2[/latex]

 

where E is the total, including rest energy of the field quantum an p isits momentum comparison to [latex]E^2-p^2c^2=m^2c^4[/latex] implies that the mass of thee quantum in a superconductor is

[latex]m_\gamma=\frac{k\hbar}{c}[/latex] the photon behaves as a massive particle in a superconductor. This is the import of the Meissner effect.

 

Now we need to make a further connection to the Bardeen-Cooper_Schreiffer (BCS theory) of superconductivity which is a microscopic theory that accounts for superconductivity by positing a scalar field [latex]\phi{/latex] (spin zero for scalar fields). Which describes a Cooper pair of electrons, the pairing is in momentu space rather than coordinate space. You can correlate the many particle wave function of Cooper pairing with the above. I'm trying to save time here lol and this is already getting lengthy.

 

The main difference between a superconductor and the Higg's field is that the Higg's field is all pervasive unlike (unlike BCS which is inside a superconductor)

 

The Higg's field through treatment gives rise to the mass of the above neutrinos in the same manner but not to photons. In point of detail the Higg's field can be treated as 4 separate fields one for each of the above. latex]\gamma, W^-, W^+, and, Z^o.[/latex]

 

Now the Higg's potential when [latex]t<t_c[/latex] has a maximum at [latex]\phi=0[/latex] and two minima at [latex]\phi=\pm A[/latex] when[latex] t>t_c][/latex] there is only a minimal at [latex]\phi=0[/latex] THIS is the Mexican hat potential.

 

[latex]V \phi=\frac{m^2}{2}\phi^2+\frac{\lambda}{4}\phi^4[/latex] where [latex]\phi^4[/latex] is the quartic self interaction.. The extremal values of [latex]V\phi[/latex], given by [latex]\partial V/\partial \phi=0[/latex] becomes

 

[latex]\phi=0,\pm\sqrt{\frac{-m^2}{\lambda}}=0,\pm a[/latex]

 

when there is no field [latex]\phi=0[/latex], the energy is not a mimimal but at a maximal, further more the lowest energy is a state in which the field does not vanish and is also two fold degenerate.

 

I hope that helps better understand the Higg's field and how it came about ie was derived in the first place. Section 10.10 Lewis Ryder "Introduction to General Relativity"..

 

You can see from this that as the field strength changes via the meta stability the mass values will also be influenced.

Edited November 17, 2016 by Mordred

[Quantum321]

Strange "When you stop posting your personal beliefs as if they were facts, I will." There you go again with your personal opinions. Until a mediator finds something wrong with my posts you will just have to live with it.

Mordred, WOW Its going to take me some time to comprehend this. I found this post by Richard Muller

 

How can the Higgs boson contain 130 times the mass of the proton but still be a constituent part of a proton?

Richard Muller, Prof Physics, UC Berkeley, auth "Now -the Physics of Time"(2016)

Written Jan 11 ·

Protons contain quarks, gluons, and many virtual particles. Virtual particles don't have the mass of real particles; they exist only for tiny times, and because of the uncertainty principle, they can have any mass. For example, the virtual photon, mediating the "force" between two electrons, typically has a mass. (The technical jargon is that the photon is "off the mass shell".)

So many particles, in their virtual form, can and do exist inside the proton, including additional quarks, pions, and the Higgs. But it is a virtual Higgs -- with the same interactions as the real Higgs, as modified by the fact that it exists only for an instant, and does not have the mass of the real Higgs.

[Mordred]

yes this is accurate guage bosons are "off shell" and not identical to the full boson particle. A common name is vector guage boson.

Edited November 17, 2016 by Mordred