The aim of this Thesis is to investigate the possibility that the observations related to the epoch
of reionization can probe not only the evolution of the IGM state, but also the cosmological background in which this process occurs. In fact, the history of the IGM ionization is indeed affected
by the evolution of the sources of ionizing photons that, under the assumption of a structure formation paradigm determined by the hierarchic growth of the matter
uctuations, results strongly
dependent on the characteristics of the background universe.
For the purpose of our investigation, we have analysed the reionization history in innovative cosmological frameworks, still in agreement with the recent observational tests related to the SNIa and the CMB probes, comparing our results with the reionization scenario predicted by the commonly used LCDM cosmology. In particular, in this Thesis we have considered two different alternative
universes. The first one is a
at universe dominated at late epochs by a dynamic dark energy component, characterized by an equation of state evolving in time. The second cosmological framework we have assumed is a LCDM characterized by a primordial overdensity field having a non-Gaussian probability distribution.
The reionization scenario have been investigated, in this Thesis, through semi-analytic approaches
based on the hierarichic growth of the matter
uctuations and on suitable assumptions concerning
the ionization and the recombination of the IGM. We make predictions for the evolution and the
distribution of the HII regions, and for the global features of reionization, that can be constrained
by future observations. Finally, we brie
y discuss the possible future prospects of this Thesis work.
| Identifer | oai:union.ndltd.org:unibo.it/oai:amsdottorato.cib.unibo.it:1671 |
| Date | 07 April 2009 |
| Creators | Crociani, Daniela <1980> |
| Contributors | Moscardini, Lauro |
| Publisher | Alma Mater Studiorum - Università di Bologna |
| Source Sets | Università di Bologna |
| Language | English |
| Detected Language | English |
| Type | Doctoral Thesis, PeerReviewed |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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