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Strukturbildung im Kosmos infolge von gravitativ getriebenen Plasma-Instabilitäten

Strukturbildung im Kosmos infolge von gravitativ getriebenen Plasma-Instabilitäten

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Prüfsumme: MD5:cf1a430e941386a22011e05a66576db3
Prüfsumme: MD5:fb27378717527486ebc32fc3db1012da

GESSNER, Eva, 2002. Strukturbildung im Kosmos infolge von gravitativ getriebenen Plasma-Instabilitäten

@phdthesis{Gener2002Struk-5048, title={Strukturbildung im Kosmos infolge von gravitativ getriebenen Plasma-Instabilitäten}, year={2002}, author={Geßner, Eva}, address={Konstanz}, school={Universität Konstanz} }

structure formation in the cosmos due to gravitational induced plasma instabilities Geßner, Eva This thesis presents a two-fluid model consisting of the photon gas and<br />the cosmic plasma for explaining the formation and evolution of galaxies,<br />in which the coupling between radiation and plasma is considered in<br />detail. Taking into account the cosmic expansion, the formation of galaxies<br />is discussed in both the Newtonian and the general relativistic theory.<br /><br />In order to determine the unstable density fluctuation modes of the system,<br />the coupled sound-wave equations are solved using the method of<br />dispersionrelations. During the hydrogen recombination the spectrum of the<br />unstable fluctuation modes coincides exactly with the mass-spectrum of<br />galaxies observed today. Furthermore an earliest possible time is obtained<br />within the cosmic evolution, where galaxy formation can set in.<br />The quasi-unstable mass range of the growing oscillating fluctuation modes<br />around 1E18 M_odot in the general relativistic calculation can<br />be connected with the observed void structure.<br /><br />Subsequently the time evolution of the matter and radiation density<br />fluctuations is investigated. Therefore the coupled sound-wave equations<br />for the amplitudes of the unstable fluctuation modes are numerically<br />integrated from times prior to the hydrogen recombination to times shortly<br />after the recombination and additionally in the general relativistic part<br />to the present time. A significant increase of the amplitudes of the matter<br />density fluctuations up to four orders of magnitude can be seen, if the<br />Universe is described by a cosmological model with positive cosmological<br />constant and positive curvature (Lemaitre-Universe) without the need of<br />an essential amount of cold non-baryonic dark matter.<br />Consequently, with this model the formation of galaxies having scales<br />observed today can be explained assuming a Lemaitre-Universe. deposit-license application/pdf deu 2011-03-24T14:52:43Z 2002 Geßner, Eva Strukturbildung im Kosmos infolge von gravitativ getriebenen Plasma-Instabilitäten 2011-03-24T14:52:43Z

Dateiabrufe seit 01.10.2014 (Informationen über die Zugriffsstatistik)

gessner1.pdf 38
gessner2.pdf 33

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