Dark Matter Stars in the Early Universe?

OriginalArlen writes "UniverseToday reports new research which suggests dark matter could have condensed to form 'dark stars' in the early universe. These stars would have been very massive and burned very slowly, fueled by non-fusion reactions, they could still be with us. Astronomers hope to better constrain theories of early galaxy and star formation with observations of gravitational lensing events caused by these ghosts of the primordial universe."

Comments

Actual research link

[martyb]

If anyone can link the actual research done I'd love to see it

Here is the PDF: Dark matter and the first stars: a new phase of stellar evolution

Here is the abstract:

Douglas Spolyar1, Katherine Freese2,3, and Paolo Gondolo4
1 Physics Dept., University of California, Santa Cruz, CA 95064
2 Michigan Center for Theoretical Physics, Dept. of Physics, University of Michigan, Ann Arbor, MI 48109
3 Visiting Miller Professor, Miller Institute, University of California, Berkeley, CA 94720
4 Physics Dept., University of Utah, Salt Lake City, UT 84112
dspolyar@physics.ucsc.edu, ktfreese@umich.edu, paolo@physics.utah.edu

A mechanism is identified whereby dark matter (DM) in protostellar halos dramatically alters the current theoretical framework for the formation of the first stars. Heat from neutralino DM annihilation is shown to overwhelm any cooling mechanism, consequently impeding the star formation process and possibly leading to a new stellar phase. A "dark star" may result: a giant (> 1 AU) hydrogen-helium star powered by DM annihilation instead of nuclear fusion, and detectable via annihilation products (gamma-rays, neutrinos, antimatter) possibly in combination with hydrogen lines. (emphasis added)

Re:Missing: Anything Provable

[megaditto]

this sounds like someone needed something to publish or perish.

An Arxiv paper doesn't really "count" as a publication for most purposes and certainly will not prevent you from "perishing" (that's what the peer-reviewed scientific journals are for).

Publishing in Arxiv is more like posting to a blog or slashdot where you semi-formally share your ideas and try to start up a discussion on the topic of interest to you.

Of course, some of the papers over there ended up being darn important.

Re:interesting

[LionMage]

Pity there's no "-1 Factually Wrong" moderation.

The idea that the net sum product of the Big Bang is 0 (zero) mass and energy is old, and has been discarded for better theories.

That means for every gram of matter there is a gram of antimatter to offset it. When the two combine they go back to 0. Matter falls into antimatter and vice versa and they cancel each other out.

Except that's not exactly right. Matter and antimatter annihilate, true, but they produce energy as the product of that annihilation. So it's not exactly a zero-sum-game as you seem to think. You may be getting confused by vacuum flux (a real phenomenon that has been experimentally observed), in which pairs of virtual particles and anti-particles are spontaneously created in a vacuum, only to disappear without a trace when they collide again. In that case, you end up with nothing (unless you're talking about a region of space arbitrarily close to the event horizon of a black hole -- that's how Hawking radiation works).

Now that the universe is mature you don't see it anymore since all the matter and antimatter are supposedly far enough away from each other that they don't annihilate anymore. Or at least often.

Try "never." The current standard model in cosmology posits that matter and antimatter were created in nearly equal quantities which condensed out of the energy of the Big Bang. The resultant mass reacted with itself, and the energy produced by these annihilations generated the next wave of particle creation. Eventually, a very slight bias in the production of matter vs. antimatter led to the overwhelming dominance of "normal" baryonic matter in the visible universe.

The idea that there are vast pockets of antimatter out there in the universe has been generally discarded. As for why there was a bias toward "normal" matter and against antimatter, I don't think that has ever been adequately explained, although there are several competing theories. It's interesting to note that in quantum mechanics, you can model antimatter interactions as a sort of time-reversal of matter interactions -- leading to the bizarre notion that antimatter is just normal matter that's "backwards" in time. Perhaps entropy provided enough of a "time arrow" to force a bias in the early universe's composition. (Or, as I sometimes muse, there might be some as-yet-unknown force that is responsible for breaking symmetry in time, and entropy as we understand it is just a product of this force.)

The "antimatter is just matter backwards in time" concept was kind of a shocker to me, taking quantum mechanics classes as a college undergrad. I'd been introduced to the concept by a story or novella that was published in Analog, and had dismissed the idea as hokey... and then one day, I cracked open one of my textbooks and saw a weird little diagram, and asked why there was an electron moving backwards in the time dimension, to which the professor responded, "That's a positron."