Starship Asterisk*

harry wrote:Phase transitions give us the various phases of Nuclear matter that can explain the missing mass and most imposrtant the intrinsic properties of supernova and the so called black holes.

Abstract: Ultracompact minihalos have recently been proposed as a new class of dark matter structure. These minihalos would be produced by phase transitions in the early Universe or features in the inflaton potential, and constitute non-baryonic massive compact halo objects (MACHOs) today. We examine the prospects of detecting ultracompact minihalos in gamma-rays if dark matter consists of self-annihilating particles. We compute present-day fluxes from minihalos produced in the e+ e- annihilation epoch, and the QCD and electroweak phase transitions in the early Universe. Even at a distance of 4 kpc, minihalos produced during the e+ e- epoch should be eminently detectable today, either by the Fermi satellite, current Air Cherenkov telescopes, or even in archival EGRET data. Within 2 kpc, they will appear as extended sources to Fermi. At 4 kpc, minihalos formed in the QCD phase transition have similar predicted fluxes to the dwarf spheroidal galaxies targeted by current indirect dark matter searches, so might also be detectable by present or upcoming experiments.

The identity of dark matter remains one of the key outstanding
problems in physics. Weakly-interacting massive
particles (WIMPs) provide a compelling solution [1]
because their weak-scale masses and cross-sections make
for a natural explanation of the observed abundance of
dark matter. As most proposed WIMPs are their own antiparticles,
high WIMP densities would also lead to high
rates of self-annihilation. Annihilation products might
then provide indirect evidence of the nature of dark matter.
Gamma-rays are particularly attractive in this respect,
as they do not suer the same problems of defection
and attenuation as massive, charged species.

harry wrote:With little understanding of dark/energy matter people will have a close mind of other research and explanations.
Bystander rightfully or wrongly deleted a post on Phase transitions Astrophysics 2009 search in arXiv.
These phase transitions are a key into understanding one form if not most of the dark/energy matter within the universe.
I just hope he does not delete this one. By doing so he will be directing scientific information along the lines of what he knows, which could be correct.

• 1. You did not read the article,
  2. You do not understand the article, or
  3. The article does not apply.

harry wrote:These phase transitions are a key into understanding one form if not most of the dark/energy matter within the universe.
http://arxiv.org/abs/0908.4082
Gamma rays from ultracompact primordial dark matter minihalos

But! on the same token, Chris maybe right in his definition of Dark/Energy matter as per what ever model he uses.

harry wrote: http://arxiv.org/abs/0908.4082
Gamma rays from ultracompact primordial dark matter minihalos

Authors: Pat Scott (OKC/Stockholm U), Sofia Sivertsson (OKC/KTH)
(Submitted on 27 Aug 2009 (v1), last revised 23 Oct 2009 (this version, v2))

Abstract: Ultracompact minihalos have recently been proposed as a new class of dark matter structure. These minihalos would be produced by phase transitions in the early Universe or features in the inflaton potential, and constitute non-baryonic massive compact halo objects (MACHOs) today. We examine the prospects of detecting ultracompact minihalos in gamma-rays if dark matter consists of self-annihilating particles. We compute present-day fluxes from minihalos produced in the e+ e- annihilation epoch, and the QCD and electroweak phase transitions in the early Universe. Even at a distance of 4 kpc, minihalos produced during the e+ e- epoch should be eminently detectable today, either by the Fermi satellite, current Air Cherenkov telescopes, or even in archival EGRET data. Within 2 kpc, they will appear as extended sources to Fermi. At 4 kpc, minihalos formed in the QCD phase transition have similar predicted fluxes to the dwarf spheroidal galaxies targeted by current indirect dark matter searches, so might also be detectable by present or upcoming experiments.

The identity of dark matter remains one of the key outstanding problems in physics. Weakly-interacting massive particles (WIMPs) provide a compelling solution [1] because their weak-scale masses and cross-sections make for a natural explanation of the observed abundance of dark matter. As most proposed WIMPs are their own antiparticles, high WIMP densities would also lead to high rates of self-annihilation. Annihilation products might then provide indirect evidence of the nature of dark matter. Gamma-rays are particularly attractive in this respect, as they do not suer the same problems of defection and attenuation as massive, charged species.

Phases of Nuclear Matter
As we know, water (H2O) can exist as ice, liquid, or steam. . . . We can make a diagram, which shows the states of H2O depending on pressure and temperature. . . . We call the mathematical relations inferred by the chart the "equation of state" of water.
. . .
Just as the state of a collection of atoms or molecules depends on temperature and pressure, we find that the state of a nucleus depends on temperature and on the density of the nucleons. Thus we may ask what is the equation of state for nuclear matter?
. . .
In a laboratory, the only possible way to heat nuclei to significant temperatures is by colliding them with other nuclei. The temperatures reached during these collisions are astounding. . . . The temperatures we can reach in nuclear collisions range up to 100 MeV and above–more than 200 million times the temperature at the surface of the Sun (~5,500 K)!
. . .
As we heat nuclei to a temperature of a few MeV, some of the nuclear "liquid" evaporates. From knowing the general form of the interactions between nucleons, we know that, just like water, the nuclear liquid also has a latent heat of vaporization, and nuclei should undergo a first-order phase transition. This liquid-gas coexistence is also expected to terminate at a critical point, the critical point of nuclear matter. One of the major thrusts of heavy ion research at laboratories such as Michigan State University’s National Superconducting Cyclotron Laboratory is to find out if these theoretical expectations are correct. Experiments try to determine at what temperature and density the critical point of nuclear matter is located.

There are major challenges that nuclear physicists face in their efforts to explore the nuclear equation of state and these nuclear phase transitions. . . .
Despite these challenges, progress in this field has been significant.
. . .
. . .
The figure shows that the phase transition between the nuclear liquid and a gas of nucleons is not the only phase transition that heavy ion scientists are studying. At even higher temperatures and densities, nucleons themselves can undergo a phase transition.
. . .
All of the theoretical and experimental challenges listed above are also present when studying the transition to the quark-gluon plasma. In addition, there is another, possibly even more severe obstacle to overcome: the quark-gluon plasma cannot survive longer than a few times 10^^-22 seconds.
. . .
What is the purpose of studying the nuclear matter phase diagram? The answer is that we need this information to understand the early history of our universe, and to understand high-density objects, called "neutron stars" in our present-day universe. . . . Thus, the study of the nuclear equation of state is connected to the initial phases of the early Universe, to ultra-violent stellar explosions, and to experiments at laboratories around the world.

harry wrote:In most cases the point is expalined within the ABS.

harry wrote:G'day

In a way I was sharing the reading that I do.

Bystander has the opinion that I do not read the links that I post.

He is mistaken

Regardless

Since no one reads the links that I post then there will be no more.

As for being public, I do not mind the links that I post been critisied thats part of the game.

I have no time to break down the posts to what is expected. In most cases the point is expalined within the ABS.

harry wrote:G'day Mishkin

Smile, did you actually read some?

harry wrote:So how do I post links that I read and want to share?

harry wrote:I did use the private message to mishkin, could this be the way?

harry wrote:What do you mean unsubscribe you?