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Locating the inner edge of a neutron star crust

Thesis (MSc (Physics))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The overall goal of this project is to study neutron star properties and locate the transition density
from the core to the crust using fifteen parameter sets of the effective Skyrme nucleon-nucleon
interaction within a method called the dynamical method. Although another approach used to
describe nucleon-nucleon interactions called the modified Gogny interaction is briefly discussed
in this work, along with a second method for locating the transition density called the
thermodynamical method, results using this interaction and method were not generated, but lays
some foundation for a PhD project to be undertaken and potentially showing the relation between
the interactions and results. The importance of results depends on how well other theoretical
approaches to the problem can reproduce those results and to what accuracy. For models to be
valid there also has to be good agreement between the theoretical results and known observables.
In this project some properties of neutron stars, such as the equation of state, saturation density,
binding energy, symmetry energy, slope and incompressibility parameters of symmetry energy
are studied. The transition density is located using the dynamical method. Results of the fifteen
Skyrme parameter sets show excellent agreement with the published values of the properties of
neutron stars and are consistent with their empirical values inferred from nuclear laboratory data,
thus validating the use of the Skyrme interactions for describing nuclear matter. / AFRIKAANSE OPSOMMING: Die hoofdoel van hierdie projek is om neutron ster eienskappe te bestudeer en die
oorgangsdigtheid vanaf die kors na die kern te vind deur gebruik te maak van vyftien parameter
stelle van die effektiewe Skyrme nukleon-nukleon interaksie binne ‘n metode genaamd die
dinamiese metode. Alhoewel ‘n ander benadering vir die beskrywing van nukleon-nukleon
interaksies, genaamd die gewysigde Gogny interaksie kortliks in hierdie werk beskryf word,
asook ‘n tweede metode, genaamd die termodinamiese metode om die oorgangsdigtheid te
bepaal, was resultate vir hierdie interaksie en metode nie gegenereer nie, maar l die fondasie vir
verdere werk aan ‘n PhD projek wat die verband tussen die twee interaksies en resultate kan wys.
Die belangrikheid van resultate hang af van hoe goed ander teoretiese benaderinge tot die
problem daardie resultate kan herproduseer en tot watter akkuraatheid. Vir modelle om geldig te
wees moet daar ook goeie ooreenkomste wees tussen teoretiese resultate en bekende
waarneembare eienskappe. In hierdie projek word sommige eieskappe van neutron sterre, soos
die toestandandsvergelyking, versadigingsdigtheid, bindingsenergie, simmetrie-energie, gradiënt
en onsaampersbaarheids parameters van die simmetrie-energie bestudeer. Die oorgangsdigtheid
word dan gevind deur gebruik te maak van die dinamiese metode. Resultate van die vyftien
Skyrme interaksie parameter stelle wys goeie ooreenstemming met die gepubliseerde waardes
van die eienskappe van neutron sterre en is konsistent met hulle empiriese waardes afgelei van
kern laboratorium data, wat die geldigheid van Skyrme interaksies vir die beskrywing van kernmaterie
bevestig.

Identiferoai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/5151
Date12 1900
CreatorsVan Rooy, Milton William
ContributorsWyngaardt, S. M., Hillhouse, G. C., University of Stellenbosch. Faculty of Science. Dept. of Physics.
PublisherStellenbosch : University of Stellenbosch
Source SetsSouth African National ETD Portal
LanguageEnglish
Detected LanguageUnknown
Format65 p. : ill.
RightsUniversity of Stellenbosch

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