<p>This is an area of active research. The current Cold Dark Matter (CDM) paradigm predicts bottom-up formation of halos, whereby smaller halos coalesce in to the larger halos we observe indirectly today through X-ray measurements of clusters. This suggests that small dark matter halos wouldn't survive to the present day.</p>

<p>There has <a href="http://astrobites.org/2011/06/06/dark-matter-micro-haloes-in-the-milky-way/" rel="nofollow">been research</a> in to the possibility of mini haloes surviving, but interactions with dense baryonic structures, such as stars, as well as streaming by an irregular galactic potential tend to wipe out any small overdensities in the distribution.</p>

<p>However, if such mini haloes did exist in the early universe they could have contributed to the collapse of primordial gas to form Population III stars. <a href="http://arxiv.org/abs/0801.4924" rel="nofollow">Simulations have been carried out</a> to investigate such a model, with Population III stellar masses comparable to those expected $(\sim100 M\odot)$.</p>

CC BY-SA 3.0
2016-02-19T08:36:41.167Z
2016-04-26T10:05:26.200Z
2016-04-26T10:05:26.200Z
christopherlovell
<p>Dark Matter is a kind of &quot;fill in the blank&quot; at the moment.  No one really has any definitive theory that has wide acceptance on what &quot;dark matter&quot; may be, never mind how it interacts with other matter.  There's still a little resistance to even saying it exists at all, although it's pretty much the mainstream now that it does.  But what it is, that's still up for grabs.</p>
<p>But I did find Tsiklauri, D. (1998) from Google. It presumes a certain type of model for dark matter, but may be what you're looking for.</p>
<p><a href="http://iopscience.iop.org/article/10.1086/306334/fulltext" rel="nofollow noreferrer">Jeans Instability of Interstellar Gas Clouds in the Background of Weakly Interacting Massive Particles</a></p>
<blockquote>
<p>Criterion of the Jeans instability of interstellar gas clouds that are gravitationally coupled with weakly interacting massive particles is revisited. It is established that presence of the dark matter always reduces the Jeans length and, in turn, the Jeans mass of the interstellar gas clouds. Astrophysical implications of this effect are discussed.</p>
</blockquote>

CC BY-SA 4.0
2015-12-21T01:41:23.580Z
2022-01-06T01:03:51.973Z
2022-01-06T01:03:51.973Z
StephenG - Help Ukraine
<p>I am wondering if there are any models of interstellar cloud collapse out there which take dark matter into account. </p>

<p>If dark matter has local perturbations or density fluctuations, then that may be a large enough effect to cause collapse of an interstellar cloud. This might increase the mass and density of a cloud enough to overcome the kinetic energy of hydrogen atoms leading to collapse.</p>

<p>Are there dark matter density variations at the scale of interstellar clouds?</p>

<dark-matter><star-formation><interstellar-medium>
Can dark matter decrease the Jeans length?
dualredlaugh
# Can dark matter decrease the Jeans length?

(Asked by: username_0 on 2015-12-12)

I am wondering if there are any models of interstellar cloud collapse out there which take dark matter into account.

If dark matter has local perturbations or density fluctuations, then that may be a large enough effect to cause collapse of an interstellar cloud. This might increase the mass and density of a cloud enough to overcome the kinetic energy of hydrogen atoms leading to collapse.

Are there dark matter density variations at the scale of interstellar clouds?

**Tags:** dark-matter, star-formation, interstellar-medium


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## 2 answers

### Answer by username_1 on 2016-02-19. Score: 5

This is an area of active research. The current Cold Dark Matter (CDM) paradigm predicts bottom-up formation of halos, whereby smaller halos coalesce in to the larger halos we observe indirectly today through X-ray measurements of clusters. This suggests that small dark matter halos wouldn't survive to the present day.

There has [been research](http://astrobites.org/2011/06/06/dark-matter-micro-haloes-in-the-milky-way/) in to the possibility of mini haloes surviving, but interactions with dense baryonic structures, such as stars, as well as streaming by an irregular galactic potential tend to wipe out any small overdensities in the distribution.

However, if such mini haloes did exist in the early universe they could have contributed to the collapse of primordial gas to form Population III stars. [Simulations have been carried out](http://arxiv.org/abs/0801.4924) to investigate such a model, with Population III stellar masses comparable to those expected $(\sim100 M\odot)$.


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### Answer by username_2 on 2015-12-21. Score: -2

Dark Matter is a kind of "fill in the blank" at the moment. No one really has any definitive theory that has wide acceptance on what "dark matter" may be, never mind how it interacts with other matter. There's still a little resistance to even saying it exists at all, although it's pretty much the mainstream now that it does. But what it is, that's still up for grabs.

But I did find Tsiklauri, D. (1998) from Google. It presumes a certain type of model for dark matter, but may be what you're looking for.

[Jeans Instability of Interstellar Gas Clouds in the Background of Weakly Interacting Massive Particles](http://iopscience.iop.org/article/10.1086/306334/fulltext)

> Criterion of the Jeans instability of interstellar gas clouds that are gravitationally coupled with weakly interacting massive particles is revisited. It is established that presence of the dark matter always reduces the Jeans length and, in turn, the Jeans mass of the interstellar gas clouds. Astrophysical implications of this effect are discussed.


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