Dark matter Definition and 935 Threads

A recent study using the VLT array has measured the temperature and size of dark matter clumps. Interestingly enough, the study has not yet been submitted to Arxiv, but will probably appear within a week. It is expected to be one of the most important papers in 2006. Here is a teaser: Dark...

http://arxiv.org/abs/astro-ph/0602519 Authors: H. Balasin, D. Grumiller Comments: 11 pages revtex4, 4 eps figures Report-no: LU-ITP 2006/002 Exact stationary axially symmetric solutions of the 4D Einstein equations with co-rotating pressureless perfect fluid sources are studied. This is of...

http://arxiv.org/abs/hep-ph/0602187 Authors: Edward A. Baltz, Marco Battaglia, Michael E. Peskin, Tommer Wizansky Comments: 121 pages, 62 figures Report-no: SLAC-PUB-11687, LBNL-59634 If the cosmic dark matter consists of weakly-interacting massive particles, these particles should be...

This should help clear up the mystery. What do you think? DARK MATTER EXPLAINED [Nereid's note: please check your mailbox, soliasenberg, for why your post was deleted.]

http://news.bbc.co.uk/1/hi/sci/tech/4679220.stm Gerry Gilmore's Cambridge team did a survey of clouds of dark matter, using several telescopes including VLT in Chile. they found no blobs of DM smaller than about 30 million solar masses, or less than 1000 lightyear diameter. They inferred...

Black holes are constructed from ordinary matter. Their charge to mass ratio, a measure of photonic interaction, is comparatively small. They have been indirectly (gravitationally) observed. They are common in the halos of galaxies where older, Population II stars have hereto collapsed, and...

Do dark matter bend light? Have they found dark matter?

I apologize in advance if this is the wrong forum for this thread... My overall question is: What specifics, if any, do we know about the "dark" stuff - ie dark energy and dark matter? Specifically: Do we know anything about what the darkstuffs are made of (either experimentally or...

there must be a lot of ways already proposed to do this. can anyone list those considered most promising? has this been the subject of a thread already today I saw this paper which claims to suggest a way to observationally distinguish MOND from DM-----to tell which is right. I think...

Google scholar has 651,000 results for dark matter and 521,000 results for dark energy, more than i could read in a life time, can anyone suggest the hot pappers on these subjects.

I would like to explore the possibility that the gravitational effects of Dark Matter might possibly be accounted for by the Unruh effect applied to the acceleration of gravity. The Unruh effect predicts a temperature associated with any acceleration. And an energy density can be found for this...

Just realized that this paper hadn't been posted here, and thought everyone might like to see this. http://xxx.lanl.gov/abs/astro-ph/0507619 Very interesting findings, not too hard to read. The ultimate point is that, traditional computer simulations of galactic rotation are done using...

I recently made a post here asking questions that where clearly rediculous. I guess I need to be more obtuse. The reason I asked it here is that I'm looking for any possible way in which the 'tornado-like' rotation of galaxies could be explained by any kind of possible atomic structure in 3D...

Can someone explain to me what is it or what is theorized to be dark matter. What effects does it have in regards to the cosmos. Thank you, vm

new study shows Dark Matter mat not exist? Relativty explains it? Look here http://www.space.com/scienceastronomy/051010_dark_matter.html" Is this valid reasoning? I noticed it hadn't been submitted to peer review.

Which alternative do you think is the most likely to solve the Dark Matter problem?

Hello All, Here is an article we have just published on a very interesting development concerning dark matter: http://www.isracast.com/tech_news/061005_tech.htm Comment are most welcome. Iddo

The Distribution of Dark Matter in Spirals Perhaps another 'epicycle' is required? Or is the Halo baryonic after all? Just a thought. Garth

This time the news is that on 21 September this paper was accepted for publication in Astrophysical Journal. It will appear in January. http://www.arxiv.org/abs/astro-ph/0506370 Galaxy Rotation Curves Without Non-Baryonic Dark Matter J. R. Brownstein, J. W. Moffat 43 pages, 7 figures, 4...

could dark matter simply be an error in general relativity or the effect of temporal effects on orbits, ie time is slower the nearer the sun, so the Earth rotates slower on the sun side, and so is pivotted towards the sun(or does this explain gravity only, or maybe the reason objects don't slow...

Hey guys, what is dark matter?what is it made up of and where is it?can any theory explain this? can string theory explain this? so please frendz help me out of this.

http://www.nature.com/news/2005/050829/full/050829-18.html [PLAIN]http://xxx.arxiv.org/PS_cache/astro-ph/pdf/0508/0508572.pdf[/URL]

http://xxx.arxiv.org/abs/astro-ph/0508572 I like the way the title of this paper captures ones attention. For a minute there I thought they had finally found some evidence for string theory. From what I understand they’re speculating on astronomical observations of dark matter, by...

http://www.arxiv.org/abs/astro-ph/0508624 This paper offers a fairly natural explanation for the universality of dark matter halo profiles. In this model the mass accretion history has two distict phases, first a fast phase dominated by frequent mergers of smaller condensations of CDM...

For anyone interested in a recent, state of the union address on dark matter: http://arxiv.org/abs/astro-ph/0508279 The Dark Side of the Universe Authors: Katherine Freese

The new paper is titled General Relativity Resolves Galactic Rotation Without Exotic Dark Matter It is on the arxiv at http://www.arxiv.org/abs/astro-ph/0507619 From the abstract

If weakly acting dark matter does not interact with photons, how is special (or general) relativity applied in its case? Signaling (or lightlike geodesics) would be hard to define where there is no electromagnetic objectivity. I guess this inertness may be a problem in determining a neutrino's...

http://arxiv.org/abs/astro-ph/0507142 Title: Constraints on dark matter and the shape of the Milky Way dark halo from the 511 keV line Authors: Y. Ascasibar (1), P. Jean (2), C. Boehm (3,4), J. Knoedlseder (2) ((1) Harvard-Smithsonian CfA, USA, (2) Centre d'Etude Spatiale des Rayonnements...

There are several scientists (including Stephen Hawking) who made calculations about our Galaxy rotation and mass... The only stable Milky Way construct they were able to come up with had to include in it's calculation the so called "Dark Matter" ... As I am a realist I just can take seriously...

Dark matter drives expansion http://arxiv.org/abs/gr-qc/0506108 Unification of dark matter and dark energy via quantum wave function collapse Authors: A. S. Majumdar, D. Home Comments: 5 pages, RevTex Dynamical wave function collapse models entail the continuous liberation of a...

Why is it necessary to assume dark matter exists in the universe? If we feel that galaxies are rotating faster than it is possible for normal matter to do so, they must have less moment of inertia. This will make their rotation fast. Hence, they should have less mass, not more! I’ve heard that...

I want to know more about dark matter. Please tell me: Why do scientists think that there should be dark matter?

1)Ok.I was wondering ..what happens after we reach singularity inside black hole?...Do we become part of the black hole and strengthen it by increasing its mass in the same amount of volume? 2) Is Dark Matter only confined to the outer stretches of the Galaxy?..or is it also found elsewhere...

I've been reading and posting in this forum for a little while. I've noticed a few things have been mentioned about dark matter, energy, and negetive gravity. I asked my physics teacher about what dark matter was; he said it was basically protons that have negetive charges and electrons that...

When I was doing science fair projects in astrophysics, sometimes I felt like asking my mentor random astronomy questions that I had in my mind. He was a very great man and taught me a lot about astronomy and kept my interest in the subject alive such that I decided I wanted to major in...

Can we detect WIMPs and axions on earth? WIMPs or/and axions are believed to be the basic constituents of dark matter.

Does anyone know of any work that has been done on the possible theoretical physics/mechanics of Dark Matter, for example if Dark Matter cannot lose energy by radiation then it presumably cannot undergo gravitational collapse in the same was as baryonic matter? A layperson's guide would be nice...

I'm not trying to advance a pet theory here .. it's really just a question. Why don't physicists serious consider the possibility of energy/mass contained in the false vacuum as the source of Dark Matter? At least I've never heard of a serious one in these terms. Real particles and their...

Can and do they exist primarily separate from ordinary matter, and how might they be detected (e. g., gravitational lensing, Newtonian mechanics)?

I was wondering what kinds of experiments we are doing to find out what DARK MATTER and DARK ENERGY is and where there being preformed

A "Weyl" theory of dark matter http://web.mit.edu/people/cabi/index.html by Hung Cheng of MIT, showing that if physics is locally conformal (independent of scale choice) then there is a vector particle he calls S which couples to a scalar particle like the hypothetical Higgs, or to a tensor...

Hey ! So we found some of that dark matter, :smile: woohoo ! But honnestly, I thought their had been a misprint on the Chandra site when I read that they calculate the temperature of these webs of particles to be 1 000 000 °C :bugeye: ! ? ! ? ! ? ! How the #!*@¤ did we not see something...

In another thread we discussed the nature and extent of the Giant Galactic Blobs!, and the nature of Dark Matter. I advocated a baryonic nature of most or all of the DM following the “Freely Coasting” Cosmology model. The question it raises is, "What form does this baryonic matter take...

Bekenstein just posted a new paper on his relativistic MOND which obviates dark matter http://arxiv.org/astro-ph/0412652 An alternative to the dark matter paradigm: relativistic MOND gravitation This is a followup of an earlier Bekenstein paper which was published in Physical Review...

http://arxiv.org/ftp/astro-ph/papers/0212/0212251.pdf

Another log for the controversy campfire http://arxiv.org/abs/astro-ph/0405282

If dark matter has mass, interacts with gravity, and is pervasive then why isn’t it gathering at points of mass and turning all the suns into black holes?

Could hot dark matter be cold dark matter? In other words did hdm cool and become cdm? And could hdm moving at or close to the speed of light exist beyond the most distant detected galaxies?

Gravitational Theory, Galaxy Rotation Curves and Cosmology without Dark Matter J. W. Moffat http://arxiv.org/abs/astro-ph/0412195 "Einstein gravity coupled to a massive skew symmetric field F_{\mu\nu\lambda} leads to an acceleration law that modifies the Newtonian law of attraction between...

General Relativity GR, and Loop Quantum Gravity LQG as well, says that space is derived from the gravitational field of matter. But the total matter in the universe is constant; whereas the space of and the amount of Dark Energy in the universe is growing. It is supposed that most of this...