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		<title>160.39.193.45 at 05:24, 29 April 2012</title>
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&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;{{One source|date=November 2013}}&lt;br /&gt;
&amp;#039;&amp;#039;&amp;#039;Holeums&amp;#039;&amp;#039;&amp;#039; are hypothetical stable, quantized gravitational bound states of [[Primordial black hole|primordial]] or [[micro black holes]].&lt;br /&gt;
&lt;br /&gt;
==Introduction==&lt;br /&gt;
&lt;br /&gt;
Holeums were proposed by L.K. Chavda and Abhijit Chavda in 2002.&amp;lt;ref&amp;gt;L.K. Chavda &amp;amp; Abhijit Chavda, [http://iopscience.iop.org/0264-9381/19/11/311 Dark matter and stable bound states of primordial black holes]&amp;lt;/ref&amp;gt; They have all the properties associated with [[cold dark matter]]. Holeums are not [[black holes]], even though they are made up of black holes.&lt;br /&gt;
&lt;br /&gt;
==Properties of Holeums==&lt;br /&gt;
&lt;br /&gt;
The [[binding energy]] &amp;lt;math&amp;gt;E_{n}&amp;lt;/math&amp;gt; of a Holeum that consists of two identical micro black holes of mass &amp;lt;math&amp;gt;m&amp;lt;/math&amp;gt; is given by&amp;lt;ref&amp;gt;L.K. Chavda &amp;amp; Abhijit Chavda, [http://arxiv.org/abs/gr-qc/0308054 Dark matter and stable bound states of primordial black holes]&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
: &amp;lt;math&amp;gt;E_{n}=-\frac{mc^{2}\alpha_{g}^{2}}{4n^{2}}&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
in which &amp;lt;math&amp;gt;n&amp;lt;/math&amp;gt; is the principal [[quantum number]], &amp;lt;math&amp;gt;n=1,2,...\infty&amp;lt;/math&amp;gt; and &amp;lt;math&amp;gt;\alpha_{g}&amp;lt;/math&amp;gt; is the gravitational counterpart of the [[fine structure constant]]. The latter is given by&lt;br /&gt;
&lt;br /&gt;
: &amp;lt;math&amp;gt;\alpha_{g}=\frac{m^{2}G}{\hbar c}=\frac{m^{2}}{m_{P}^{2}}&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
where:&lt;br /&gt;
&lt;br /&gt;
: &amp;lt;math&amp;gt;\hbar&amp;lt;/math&amp;gt; is the [[Planck constant]] divided by &amp;lt;math&amp;gt;2\pi&amp;lt;/math&amp;gt;;&lt;br /&gt;
: &amp;lt;math&amp;gt;c&amp;lt;/math&amp;gt; is the [[speed of light]] in vacuum;&lt;br /&gt;
: &amp;lt;math&amp;gt;G&amp;lt;/math&amp;gt; is the [[gravitational constant]].&lt;br /&gt;
&lt;br /&gt;
The &amp;lt;math&amp;gt;n^{\text{th}}&amp;lt;/math&amp;gt; excited state of a Holeum then has a mass that is given by&lt;br /&gt;
&lt;br /&gt;
: &amp;lt;math&amp;gt;m_{H}=2m+\frac{E_{n}}{c^{2}}&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
The Holeum&amp;#039;s atomic transitions cause it to emit [[gravitational radiation]].&lt;br /&gt;
&lt;br /&gt;
The radius of the &amp;lt;math&amp;gt;n^{\text{th}}&amp;lt;/math&amp;gt; excited state of a Holeum is given by&lt;br /&gt;
&lt;br /&gt;
: &amp;lt;math&amp;gt;r_{n}=\left(  \frac{n^{2}R}{\alpha_{g}^{2}}\right)  \left(  \frac{\pi^{2}}{{8}}\right)&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
where:&lt;br /&gt;
&lt;br /&gt;
: &amp;lt;math&amp;gt;R=\left(  \frac{2mG}{c^{2}}\right)&amp;lt;/math&amp;gt; is the [[Schwarzschild radius]] of the two identical micro black holes that constitute the Holeum.&lt;br /&gt;
&lt;br /&gt;
The Holeum is a stable particle. It is the gravitational analogue of the [[hydrogen atom]]. It occupies space. Although it is made up of black holes, it itself is not a black hole. As the Holeum is a purely gravitational system, it emits only gravitational radiation and no [[electromagnetic radiation]]. The Holeum can therefore be considered to be a [[dark matter]] particle.&amp;lt;ref&amp;gt;M. Yu. Khlopov, [http://arxiv.org/abs/arXiv:0801.0116 Primordial Black Holes]&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Macro Holeums and their properties==&lt;br /&gt;
&lt;br /&gt;
A Macro Holeum is a quantized gravitational bound state of a large number of micro black holes. The energy eigenvalues of a Macro Holeum consisting of &amp;lt;math&amp;gt;k&amp;lt;/math&amp;gt; identical micro black holes of mass &amp;lt;math&amp;gt;m&amp;lt;/math&amp;gt; are given by&amp;lt;ref&amp;gt;L.K. Chavda &amp;amp; Abhijit Chavda, [http://arxiv.org/abs/0903.0703 Quantized Gravitational Radiation from Black Holes and other Macro Holeums in the Low Frequency Domain]&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
: &amp;lt;math&amp;gt;E_{k}=-\frac{p^{2}mc^{2}}{2n_{k}^{2}}\left(  1-\frac{p^{2}}{6n^{2}}\right)^{2}&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
where &amp;lt;math&amp;gt;p=k\alpha_{g}&amp;lt;/math&amp;gt; and &amp;lt;math&amp;gt;k\gg2&amp;lt;/math&amp;gt;. The system is simplified by assuming that all the micro black holes in the core are in the same quantum state described by &amp;lt;math&amp;gt;n&amp;lt;/math&amp;gt;, and that the outermost, &amp;lt;math&amp;gt;k^{th}&amp;lt;/math&amp;gt; micro black hole is in an arbitrary quantum state described by the principal quantum number &amp;lt;math&amp;gt;n_{k}&amp;lt;/math&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
The &amp;#039;&amp;#039;physical radius&amp;#039;&amp;#039; of the bound state is given by&lt;br /&gt;
&lt;br /&gt;
: &amp;lt;math&amp;gt;r_{k}=\frac{\pi^{2}kRn_{k}^{2}}{16p^{2}\left(  1-\frac{p^{2}}{6n^{2}}\right)}&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
The mass of the Macro Holeum is given by&lt;br /&gt;
&lt;br /&gt;
: &amp;lt;math&amp;gt;M_{k}=mk\left(  1-\frac{p^{2}}{6n^{2}}\right)&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
The Schwarzschild radius of the Macro Holeum is given by&lt;br /&gt;
&lt;br /&gt;
: &amp;lt;math&amp;gt;R_{k}=kR\left(  1-\frac{p^{2}}{6n^{2}}\right)&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
The [[entropy]] of the system is given by&lt;br /&gt;
&lt;br /&gt;
: &amp;lt;math&amp;gt;S_{k}=k^{2}S\left( 1-\frac{p^{2}}{6n^{2}}\right)&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
where &amp;lt;math&amp;gt;S&amp;lt;/math&amp;gt; is the entropy of the individual micro black holes that constitute the Macro Holeum.&lt;br /&gt;
&lt;br /&gt;
== The ground state of Macro Holeums ==&lt;br /&gt;
&lt;br /&gt;
The [[ground state]] of Macro Holeums is characterized by &amp;lt;math&amp;gt;n=\infty&amp;lt;/math&amp;gt; and &amp;lt;math&amp;gt;n_{k}=1&amp;lt;/math&amp;gt;. The Holeum has maximum binding energy, minimum physical radius, maximum Schwarzschild radius, maximum mass, and maximum entropy in this state.&lt;br /&gt;
&lt;br /&gt;
Such a system can be thought of as consisting of a gas of &amp;lt;math&amp;gt;k-1&amp;lt;/math&amp;gt; free (&amp;lt;math&amp;gt;n=\infty&amp;lt;/math&amp;gt;) micro black holes that is bounded and therefore isolated from the outside world by a solitary outermost micro black hole whose principal quantum number is &amp;lt;math&amp;gt;n_{k}=1&amp;lt;/math&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
== Stability of Holeums ==&lt;br /&gt;
&lt;br /&gt;
It can be seen from the above equations that the condition for the stability of Holeums is given by&lt;br /&gt;
&lt;br /&gt;
&amp;lt;math&amp;gt;\frac{p^{2}}{6n^{2}}&amp;lt;1&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Substituting the relations &amp;lt;math&amp;gt;p=k\alpha _{g}&amp;lt;/math&amp;gt; and &amp;lt;math&amp;gt;\alpha _{g}=\frac{m^{2}}{m_{P}^{2}}&amp;lt;/math&amp;gt; into this inequality, the condition for the stability of Holeums can be expressed as&lt;br /&gt;
&lt;br /&gt;
&amp;lt;math&amp;gt;m&amp;lt;m_{P}\left( 6\right) ^{\frac{1}{4}}\left( \frac{n}{k}\right) ^{\frac{1}{2}}&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
The ground state of Holeums is characterized by &amp;lt;math&amp;gt;n=\infty&amp;lt;/math&amp;gt;, which gives us &amp;lt;math&amp;gt;m&amp;lt;\infty&amp;lt;/math&amp;gt; as the condition for stability. Thus, the ground state of Holeums is guaranteed to be always stable.&lt;br /&gt;
&lt;br /&gt;
== Black Holeums ==&lt;br /&gt;
&lt;br /&gt;
A Holeum is a black hole if its physical radius is less than or equal to its Schwarzschild radius, i.e. if&lt;br /&gt;
&lt;br /&gt;
&amp;lt;math&amp;gt;r_{k}\leqslant R_{k}&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Such Holeums are termed Black Holeums. Substituting the expressions for &amp;lt;math&amp;gt;r_{k}&amp;lt;/math&amp;gt; and &amp;lt;math&amp;gt;R_{k}&amp;lt;/math&amp;gt;, and simplifying, we obtain the condition for a Holeum to be a Black Holeum to be&lt;br /&gt;
&lt;br /&gt;
&amp;lt;math&amp;gt;m\geqslant \frac{m_{P}}{2}\left( \frac{\pi n_{k}}{k}\right) ^{\frac{1}{2}}&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
For the ground state, which is characterized by &amp;lt;math&amp;gt;n_{k}=1&amp;lt;/math&amp;gt;, this reduces to&lt;br /&gt;
&lt;br /&gt;
&amp;lt;math&amp;gt;m\geqslant \frac{m_{P}}{2}\left( \frac{\pi}{k}\right) ^{\frac{1}{2}}&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Black Holeums are an example of black holes with internal structure. Black Holeums are quantum black holes whose internal structure can be fully predicted by means of the quantities &amp;lt;math&amp;gt;k&amp;lt;/math&amp;gt;, &amp;lt;math&amp;gt;m&amp;lt;/math&amp;gt;, &amp;lt;math&amp;gt;n&amp;lt;/math&amp;gt;, and &amp;lt;math&amp;gt;n_{k}&amp;lt;/math&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
== Holeums and cosmology ==&lt;br /&gt;
&lt;br /&gt;
Holeums are speculated to be the progenitors of a class of short duration [[gamma ray bursts]].&amp;lt;ref&amp;gt;S. Al Dallal, [http://adsabs.harvard.edu/abs/2007AdSpR..40.1236A Holeums as potential candidates for some short-lived gamma ray bursts]&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;S. Al Dallal, [http://adsabs.harvard.edu/abs/2010AdSpR..46..468D Primordial black holes and Holeums as progenitors of Galactic diffuse gamma-ray background]&amp;lt;/ref&amp;gt; It is also speculated that Holeums give rise to [[cosmic rays]] of all energies, including [[ultra-high-energy cosmic rays]].&amp;lt;ref&amp;gt;L.K. Chavda &amp;amp; Abhijit Chavda, [http://arxiv.org/abs/0806.0454 Ultra High Energy Cosmic Rays from decays of Holeums in Galactic Halos]&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== References ==&lt;br /&gt;
&amp;lt;!--- See [[Wikipedia:Footnotes]] on how to create references using &amp;lt;ref&amp;gt;&amp;lt;/ref&amp;gt; tags which will then appear here automatically --&amp;gt;&lt;br /&gt;
{{Reflist}}&lt;br /&gt;
&lt;br /&gt;
==External links==&lt;br /&gt;
* [http://actaphysica.com Acta Physica: Chronicles the development of the theory of Holeums]&lt;br /&gt;
* [http://actaphysica.com/black-holes/a-stable-holeum/ A Stable Holeum]&lt;br /&gt;
* [http://actaphysica.com/black-holes/gravitational-radiation/ Gravitational Radiation from Holeums]&lt;br /&gt;
* [http://actaphysica.com/holeum/constructing-a-macro-holeum-from-the-inside-out/ Constructing a Macro Holeum from the Inside Out]&lt;br /&gt;
* [http://actaphysica.com/holeum/the-black-holeum/ The Black Holeum]&lt;br /&gt;
&lt;br /&gt;
{{Dark matter}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Physical cosmology]]&lt;br /&gt;
[[Category:Dark matter]]&lt;br /&gt;
[[Category:Large-scale structure of the cosmos]]&lt;br /&gt;
[[Category:Astroparticle physics]]&lt;br /&gt;
[[Category:Exotic matter]]&lt;br /&gt;
[[Category:Unsolved problems in physics]]&lt;br /&gt;
[[Category:Particle physics]]&lt;br /&gt;
[[Category:Theoretical physics]]&lt;br /&gt;
[[Category:Hypothetical particles]]&lt;/div&gt;</summary>
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