Does Dark Anti-Matter exist?

[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?