Browsing Institutt for teoretisk astrofysikk by Issue Date
Now showing items 21-40 of 1306
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Spicules (Master thesis / Masteroppgave, 2008)The solar chromosphere has previously been thought to be a homogenic layer of the solar atmosphere, but better observations have made it evident that the chromosphere is a highly dynamic area. Spicules are structures ...
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(Master thesis / Masteroppgave, 2008)
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(Master thesis / Masteroppgave, 2008)Systematic anomalies that seem to follow the first ionisation potential (FIP) of the minor, heavy elements at the sun, have been found when comparing the observed elemental abundances in the upper solar atmosphere with the ...
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2008)Conditional sampling methods are generalized by applying a matched-filter on the reference signal. This generalized method is illustrated by data obtained in a magnetized toroidal plasma without rotational transform. By ...
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(Master thesis / Masteroppgave, 2009)The cosmic microwave background (CMB) radiation at 2.7 K is the leftover radiation from the Big Bang. By studying this radiation we can extract much information about the universe we live in. CMB experiments over the last ...
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(Master thesis / Masteroppgave, 2009)I have investigated the total energy of Friedmann-Robertson-Walker universes. This is an interesting issue, because if the energy of the universe turns out not to be conserved, it will be in conflict with our common ...
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(Master thesis / Masteroppgave, 2009)
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(Master thesis / Masteroppgave, 2009)En mulig forklaring på at universet gikk inn i en fase av akselerert ekspansjon for 5-6 milliarder år siden, er at energitettheten i universet inneholder et bidrag fra et dynamisk skalarfelt. Problemet med denne forklaringen ...
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(Master thesis / Masteroppgave, 2010)The theory of inflation gives certain predictions for the amount of primordial gravitational waves compared to the amount of density perturbations. These predictions are, in principle, verifiable through observation of the ...
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(Master thesis / Masteroppgave, 2010)The solar chromosphere is a region where the thermodynamics are out of equilibrium, and realistic values of temperature and electron densities here are difficult to obtain. Hydrogen, being the most abundant element in solar ...
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(Master thesis / Masteroppgave, 2010)Neutrino cosmology is a very interesting field of research, where properties of some of the smallest constituents of the universe are probed by the very largest structures of the universe; large scale structures of the ...
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(Master thesis / Masteroppgave, 2010)The statistical analysis of the Cosmic Microwave Background radiation to make estimates of the Power Spectrum is a comutationally heavy operation, involving large covariance matrices. In this thesis I explore the possibility ...
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(Master thesis / Masteroppgave, 2010)We investigate scalar-field theories with a field-dependent coupling to matter and show the existence of a chameleon mechanism. The thin-shell solutions for a spherical body are found, and used to investigate the consequences ...
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(Master thesis / Masteroppgave, 2010)
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(Doctoral thesis / Doktoravhandling, 2010)
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(Doctoral thesis / Doktoravhandling, 2010)
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(Master thesis / Masteroppgave, 2010)In this thesis the correlation between star formation and dynamical state of a statistical well defined selection of galaxy clusters have been studied. From simulations and theory it is expected strong correlations between ...
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(Master thesis / Masteroppgave, 2011)The standard model of cosmology has proven to be a great success. Through measurements of the Cosmic Microwave Background radiation, cosmologists have been able to constrain parameters such as the age and geometry of the ...
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(Master thesis / Masteroppgave, 2011)This thesis is a study of the dynamics and virialization of cosmic structures in the framework of flat cosmological models where the properties of the dark energy component plays an important role in the global and local ...
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(Master thesis / Masteroppgave, 2011)There have been many reports on anomalies in the CMB from different research groups. In this work statistical tests using the gradients of the CMB temperature, applied to the seven year WMAP data, have been investigated. ...