Could Neutrinos Be the Key to Understanding Dark Matter?

[WhiteKnights]

I imagine it must...Could we have dark anti-matter in our universe that doesn't interact with ordinary matter?
Would this example say Baryon asymmetry?

 

[cristo]

Dark matter doesn't interact by the electromagnetic force, thus is not charged. Hence there is no such thing as dark anti matter.

 

[Adonis]

dark matte is a form of ordinary matter as u said ,,,,just interact gravitational forces
right?

 

[WhiteKnights]

Wow,I forget the basic definition, thinking of something more complex...

We don't know what dark matter is made of right?

 

[mgb_phys]

Dark matter doesn't interact by the electromagnetic force, thus is not charged. Hence there is no such thing as dark anti matter.

There are anti neutrinos and anti neutrons.
Do you mean that if dark matter is non-baryonic you can't have anti dark-matter?
Presumably only particles with spin can have anti particles?

We don't know what dark matter is made of right?

There are two main theories, cold dark matter is ordinary stuff ( gas, dust, rocks) that is too cold and dark to see but still has a gravitational effect, because we can model the formation rate of material from the bigbang quite well it doesn;t look like there could be enough of this.
Hot dark matter (or non-baryonic) is unknown particles that don't have electromagnetic effects so don't give off light. This looks more likely, but there is always a danger of coming up with a solution that involves being able to 'make up' whatever properties you like for your solution.

 

[Adonis]

Hot dark matter (or non-baryonic) is unknown particles that don't have electromagnetic effects so don't give off light. This looks more likely, but there is always a danger of coming up with a solution that involves being able to 'make up' whatever properties you like for your solution.

Astrophyiscs measured gravitational effect of dark matter
surround the galaxies right? as the gravitational lenses

 

[mgb_phys]

I don't know if you would call a gravitational lens an electromagnetic effect.
Perhaps I phrased it badly - dark matter doesn't generate light and doesn't seem to effect the properties of light passing through/near it, so we cannot see it directly - hence dark.

 

[metalgirl2045]

Dark matter doesn't interact by the electromagnetic force, thus is not charged. Hence there is no such thing as dark anti matter.

So what's an antineutron? Antihydrogen? And like someone else said, antinetrino? OK, so the first two have internal components which are charged, but having charge is not the requirement for having an antiparticle, antimatter has all quantum numbers reversed, including charge if applicable.

If dark matter is made of supersymmetric particles, then I'm pretty sure those have antiparticles just like normal matter does. A quick search for "anti-neutralino" (my favourite DM candiate) on Google throws up several scientific papers, so I didn't sleep through my supersymmetry lectures and dream it! Of course, it might not be supersymmetric particle, but we can't say for sure whether the type of particle dark matter is made of has an antiparticle until we know what it is!

As for matter/antimatter asymmetry, I presume it must either be all dark matter or all anti-dark-matter or it would have annihilated by now. I presume any asyemmetry would be through pretty much the same mechanism as the matter/anitmatter asymmetry in normal matter, so I would be very suprised if the DM was all antimatter.

 

[Adonis]

I don't know if you would call a gravitational lens an electromagnetic effect.
Perhaps I phrased it badly - dark matter doesn't generate light and doesn't seem to effect the properties of light passing through/near it, so we cannot see it directly - hence dark.

what i meant it that the dark matter has a gravitational effect on light...
not electromagnetic effect...(by stimulating electrons if electrons exist in dark matter)
just like when a light beam passes near to a star or
his path will be curved for a little...so what can we say about a galaxy?
am i right?

 

[Einstein Pie]

if there's antimatter, there should be anti dark matter

 

[friend]

if there's antimatter, there should be anti dark matter

Antimatter is exactly the same as matter except it has the opposite electrical charge. Since Dark Matter seems to have no interaction with electrical charge, it cannot have an opposite electrical charge. The answer would seem to be, no.

 

[Antiphon]

Uncharged particles can have antiparticles.

 

[inflector]

This is all speculation. No one knows what dark matter is. Until we find it, there isn't even any direct proof that it exists as we have only "seen it" from the effects which most attribute to it (rather than some modified gravity theory).

Since know one knows what it is, (or even, some small groups might argue, if it exists), no one can tell you if there are dark-matter anti-particles as we don't really know how to begin to argue what that might mean.

Anti-what?

We know what dark matter does and what it cannot be but we don't know what it is.

 

[jeblack3]

There's an argument called the "WIMP miracle" that can explain the amount of dark matter present in the universe today if dark matter particles and their antiparticles were produced in equal numbers and have been annihilating ever since, provided the particles have a weak-scale mass and cross section. So it's plausible that there's equal amounts of dark matter and antimatter. But the argument also works if the dark matter particle is its own antiparticle, which is a strong possibility given that these particles can't be charged. It's all speculation, though, until we find out what dark matter really is.

 

[twofish-quant]

I imagine it must...Could we have dark anti-matter in our universe that doesn't interact with ordinary matter?
Would this example say Baryon asymmetry?

Absolutely yes...

In fact, people have used the possibility that dark anti-matter/matter exists to put limits on what it might be. Start at page 73 on this paper

http://arxiv.org/PS_cache/hep-ph/pdf/0404/0404175v2.pdf

The idea is that if dark matter was particle X, some of it must be particle anti-X, and therefore we should see gamma rays or positrons from X and anti-X annihilating each other. If we go out looking for these gamma rays or positions, and we see them, they we figure out what it is. If we don't see them (which we don't), we can figure out what dark matter isn't.

 

[map19]

My rough guide is that stuff you see in the night sky all lit up is about 4% of the mass of the universe, and it's all baryonic.
Other baryonic stuff you can't see is cold , like black holes, dark stars, lone planets , asteroids, shrapnel, and gas. About 8%.
Then there's hot dark matter - mostly neutrinos. Some mass but probably a small percentage.
Unknown dark matter about 12%.
dark energy about 70%.

 

[coronzon93]

My thoughts are that there is Matter/Antimatter and yes, Dark Matter/Dark Antimatter. My thought on that is that Dark matter has its own set of quarks and bosons. So there would be Dark Leptons, Dark Mesons, Dark Baryons, Dark Bimesons, Dark Barymesons, Dark Trimesons and Dark Dibaryons. Matter/Antimatter DIRECTLY interacts with Matter/Antimatter. Dark Matter/Dark Antimatter DIRECTLY interacts with Dark Matter/Dark Antimatter. My own (strongly disputable) theory on annihilation is that when a particle interacts with its antiparticle, the annihilation yields a decay series of particles of the opposing kind. e.g. a Proton interacts with an Antiproton, the Matter yield is nothing, but Dark Matter yield occurs (not a Dark Proton and Dark Antiproton, but can't rule out the possiblity).

 

[phinds]

if there's antimatter, there should be anti dark matter

Why? Do you have any science to back up that statement?

 

[surajt88]

It does seem that when a dark matter particle meets its anti-particle, both would be annihilated.

 

[PAllen]

One of the more popular proposals for dark matter is the lightest (therefore stable) neutralino of supersymmetric models. In such models, the neutralino is its own antiparticle.

 

[wildwill]

they found positrons by using the Earth's magnetic field and looking at the aura borialus
so anti
matter could exist

 

[Drakkith]

they found positrons by using the Earth's magnetic field and looking at the aura borialus
so anti
matter could exist

Antimatter does exist. Are you referring to an antiparticle to dark matter?

 

[wildwill]

wouldnt the antiparticle be white matter

or photons

 

[Drakkith]

wouldnt the antiparticle be white matter

or photons

I've never heard of "white matter". Are you talking about normal matter that compose you and I and most of the visible universe? If so, then no, it would not be that. Normal matter has it's own antiparticles. And photons are their own antiparticle, not one to dark matter. It is thought that dark matter doesn't even interact via the electromagnetic force, so photons wouldn't even be able to interact except through gravity with dark matter.

 

[wildwill]

oh okay so would black wholes be dark mater

 

[Drakkith]

oh okay so would black wholes be dark mater

No. Instead of randomly suggesting different things as dark matter you should read up on it a little bit. Hit up wikipedia and search for dark matter on it.

 

[boson18]

faraday rotation could have some effect to the optical properties that we see, is it known if z-pinches could produce lensing effects?

 

[StevenJParkes]

Hypothetically. On the assumption that dark antimatter exists. If it does and if we could trap it, would it then be possible to use it as an energy source by making it interact with dark matter? How destructive could that be? and what other consequences might there be?

 

[StevenJParkes]

The other hypothetical question that led to the above one is as follows: "Is it possible that antimatter is the source of the limit to the speed of light?

 

[StevenJParkes]

My thoughts regarding the above questions relate to finding a method of exceeding the speed of light for the sake of space travel some time in the future.

 

[StevenJParkes]

My thoughts are that there is Matter/Antimatter and yes, Dark Matter/Dark Antimatter. My thought on that is that Dark matter has its own set of quarks and bosons. So there would be Dark Leptons, Dark Mesons, Dark Baryons, Dark Bimesons, Dark Barymesons, Dark Trimesons and Dark Dibaryons. Matter/Antimatter DIRECTLY interacts with Matter/Antimatter. Dark Matter/Dark Antimatter DIRECTLY interacts with Dark Matter/Dark Antimatter. My own (strongly disputable) theory on annihilation is that when a particle interacts with its antiparticle, the annihilation yields a decay series of particles of the opposing kind. e.g. a Proton interacts with an Antiproton, the Matter yield is nothing, but Dark Matter yield occurs (not a Dark Proton and Dark Antiproton, but can't rule out the possiblity).

Do you think its possible that matter is created from the interaction between Dark matter and Dark antimatter? Could this be an explanation for the "Big Bang" expansion of the Universe?

 

[Whovian]

Possible, but the big bang? If I'm understanding your question right, you're wondering if it's possible for the big bang to have resulted from an interaction of Dark Matter and "Dark Antimatter." According to the current theory, time didn't exist before the big bang. There was no before the big bang. And anyways, it wasn't an explosion at a certain location in space. It, erm, occurred everywhere simultaneously. (Well, sort of.) If I'm misunderstanding, could you please explain your theory in a little more detail?

 

[Drakkith]

Hypothetically. On the assumption that dark antimatter exists. If it does and if we could trap it, would it then be possible to use it as an energy source by making it interact with dark matter? How destructive could that be? and what other consequences might there be?

Welcome to PF Steven.
Dark antimatter isn't theorized to exist. Not only that, but dark matter itself doesn't interact via the electromagnetic force, so any supposed dark antimatter wouldn't be capable of being trapped.

The other hypothetical question that led to the above one is as follows: "Is it possible that antimatter is the source of the limit to the speed of light?

What? This question doesn't make any sense. Do you understand what antimatter actually is? I highly suggest you read up on it on wikipedia.

My thoughts regarding the above questions relate to finding a method of exceeding the speed of light for the sake of space travel some time in the future.

FTL travel isn't allowed per PF rules, as it is pure unsupported speculation.

Do you think its possible that matter is created from the interaction between Dark matter and Dark antimatter? Could this be an explanation for the "Big Bang" expansion of the Universe?

Steven, I highly suggest you read up on the basics of General Relativity, Cosmology, and Quantum Mechanics before asking questions such as these. Currently you don't seem to know enough to ask an appropriate question. If you have questions about the basic concepts in those areas feel free to ask and we would be glad to help.

 

[StevenJParkes]

The other hypothetical question that led to the above one is as follows: "Is it possible that antimatter is the source of the limit to the speed of light?

This is embarrassing. I meant. Is it possible that dark matter limits the speed of light. It appears to have gravitational effects.

 

[StevenJParkes]

I am aware that the Big Bang occurred everywhere at the same time. I'm just speculating that this process is still happening as a possible, or impossible, explanation of the acceleration of the expansion of the universe.

 

[phinds]

Dark matter BENDS light, as has been pointed out. What do you mean by "dark matter limits the speed of light" ?

Dark matter has nothing to do with the acceleration of the expansion of the universe.

Your concepts seem to be quite garbled.

 

[Chronos]

There is so much dark matter in the universe it is unlikely much of it is 'anti' dark matter. We would otherwise expect to see an abundance of spurious gamma radiation in the cosmic background - which is not observed. It also appears probable dark matter is not a half spin particle meaning it has no anti particle equivalent.

 

[StevenJParkes]

There is so much dark matter in the universe it is unlikely much of it is 'anti' dark matter. We would otherwise expect to see an abundance of spurious gamma radiation in the cosmic background - which is not observed. It also appears probable dark matter is not a half spin particle meaning it has no anti particle equivalent.

Makes sense. So my line of questions meets a dead end. Still, I don't truly believe that the speed of photons is unaffected in a vacuum as we know it. This is because gravity would still exist in a vacuum should such a thing as a true vacuum exist. Perhaps the value of c would be different to what Einstein theorized in the absence of the effects of matter, dark or otherwise.

 

[Drakkith]

Makes sense. So my line of questions meets a dead end. Still, I don't truly believe that the speed of photons is unaffected in a vacuum as we know it. This is because gravity would still exist in a vacuum should such a thing as a true vacuum exist. Perhaps the value of c would be different to what Einstein theorized in the absence of the effects of matter, dark or otherwise.

I fail to see what gravity has to do with the speed of light. Also, there is nowhere in the universe that is free of gravity. Even the voids between galaxy superclusters have gravity.

 

[StevenJParkes]

I could be mistaken. If gravity could bend light it must be able to limit its velocity. Perhaps, outside our universe there is a void...a real vacuum and the universe is rushing off to form an equilibrium. It would be interesting though, if there were other universes rushing towards us, or something of that nature.

 

[Drakkith]

I could be mistaken. If gravity could bend light it must be able to limit its velocity.

I don't believe this happens.

Perhaps, outside our universe there is a void...a real vacuum and the universe is rushing off to form an equilibrium. It would be interesting though, if there were other universes rushing towards us, or something of that nature.

Please, try to avoid speculation without references to back it up.

 

[phinds]

I could be mistaken. If gravity could bend light it must be able to limit its velocity.

No, that does not follow. Gravity changes the geodesic that light follows but the photons still travel at c.

Even inside a black hole where light cannot escape, it is still traveling LOCALLY at c, because the black hole just warps the geodesic.

You say

I don't truly believe that the speed of photons is unaffected in a vacuum as we know it

You really need to get over this thought that it matters what you believe. You should study physics, not make stuff up.

 

[StevenJParkes]

Please forgive me. I will stop this. I was under the impression that thinking outside the box may stimulate something useful.

 

[phinds]

Please forgive me. I will stop this. I was under the impression that thinking outside the box may stimulate something useful.

Thinking outside the box is a GREAT thing to do, but ONLY after you understand what the box is.

 

[Drakkith]

Please forgive me. I will stop this. I was under the impression that thinking outside the box may stimulate something useful.

Bouncing off what phinds said, thinking outside the box requires that you understand how current theories work. Not just in an informal "i read a book or two on it" way, but an actual understanding of the math that governs the theory. Otherwise, similar to what Phinds said, you don't know where the box is or where it ends.

 

[Physgeek123]

Basically, there is no reason why anti dark matter can't exist. True, that it is not charged, but that can be perfectly explained by anti neutrons. Antineutrons have equal amounts of positrons and antiprotons.

A different explanation according to my theory:

Also on another note, since neutrinos have no charge and are not visible, could it be possible that neutrinos could be a new fundamental particle for dark matter? Maybe things like neutrinoprotons and neutrinoelectrons could exist. And since every particle has a anti matter part, nuetrinoparticles might as well have a antinuetrinoparticle counterpart? I'm confused about all this, but you tell me.

 

[mfb]

True, that it is not charged, but that can be perfectly explained by anti neutrons.

Wait, what? Antineutrons decay (into charged antiparticles), and they would react with baryonic matter via the strong interaction. This would be really bad for life.

Also on another note, since neutrinos have no charge and are not visible, could it be possible that neutrinos could be a new fundamental particle for dark matter?

The energy density of neutrinos can be calculated. It is not negligible, but it is not large enough to explain the amount of dark matter present in the universe.

Maybe things like neutrinoprotons and neutrinoelectrons could exist

No. Unless you write a paper with a theory where they pop up as result of the theory.
It is bad that theoreticians invent so many particles with a mathematical foundation. We don't need even more particle names without any theory behind it.

 

[Drakkith]

Basically, there is no reason why anti dark matter can't exist. True, that it is not charged, but that can be perfectly explained by anti neutrons. Antineutrons have equal amounts of positrons and antiprotons.

They do not. Antineutrons are composed of one up antiquark and two down antiquarks. An normal neutron is composed of one up quark and two down quarks. Protons and electrons, or their antimatter counterparts, do not make up neutrons and antineutrons.

A different explanation according to my theory:

Also on another note, since neutrinos have no charge and are not visible, could it be possible that neutrinos could be a new fundamental particle for dark matter? Maybe things like neutrinoprotons and neutrinoelectrons could exist. And since every particle has a anti matter part, nuetrinoparticles might as well have a antinuetrinoparticle counterpart? I'm confused about all this, but you tell me.

I suggest you read the following article.
http://en.wikipedia.org/wiki/Elementary_particle