Show simple item record

dc.contributor.authorDodds, Stephen Jamesen
dc.date.accessioned2018-01-31T11:42:40Z
dc.date.available2018-01-31T11:42:40Z
dc.date.issued1996en
dc.identifier.urihttp://hdl.handle.net/1842/27918
dc.description.abstractA review of the cosmological observations and theory necessary for an understanding of the formation and evolution of cosmic large-scale structure is presented in Chapter 1.en
dc.description.abstractThe evolution of large-scale structure in the Universe is well understood in the linear regime, where the density is close to the mean density. W here the density contrast is large, the linearization o f the equations o f motion is no longer valid, and new techniques are needed. To this end, analytic arguments are combined with n -b od y simulations in Chapter 2, resulting in an analytic correction for the non-linear evolution o f clustering. This method, and models o f bias and redshift-space distortion, are then applied to a number o f observational power spectra, in order to reconstruct the linear power spectrum o f cosmic mass fluctuations. Constraints are put on the values o f bias parameters, and a high degree o f redshift-space distortion is required, 420'6/bIRAS — 1-0 dt 0-2. A Cold Dark M atter power spectrum can be fitted to the data, provided flh = 0.255 ± 0.017en
dc.description.abstractChapter 3 is concerned with the formation of galaxy clusters through gravitational col­lapse. The non-linear techniques developed in Chapter 2 are used to set up the initial conditions for numerical n-body simulations such that the final power spectra are nearly the same for two different cosmological models, 42 = 1 and 42 = 0.2. Galaxy clusters formed in these simulations are identified, and a mean density profile calculated. It is shown that although differences in power spectra have been largely eliminated, significant differences remain in the density profile under different cosmological conditions.en
dc.description.abstractIn Chapter 4, the angular correlation function, w(9), of faint blue galaxies is considered. Simple models of the evolution of clustering are unable to reproduce the observed u>(.#) o f the faint galaxies, over-predicting the amplitude of w{6) by nearly an order of magnitude. The non-linear evolution model of Chapter 2 is applied to the present epoch correlation function, and it is found that the agreement with the observations is significantly im­proved, and that the model predictions are consistent with the observations, provided that the faint blue galaxies lie at the highest redshift allowed by the observations. Low Q models are disfavoured, as they are unable to reproduce the observed shape of w(9),approximately described by a power-law. A Cold Dark M atter model, with ii = 1, is able to reproduce this shape well.en
dc.publisherThe University of Edinburghen
dc.relation.ispartofAnnexe Thesis Digitisation Project 2017 Block 16en
dc.relation.isreferencedbyAlready catalogueden
dc.titleNon-linear effects in the evolution of galaxy clusteringen
dc.typeThesis or Dissertationen
dc.type.qualificationlevelen
dc.type.qualificationnamePhD Doctor of Philosophyen


Files in this item

This item appears in the following Collection(s)

Show simple item record