Sökning: "CDM"
Visar resultat 1 - 5 av 82 uppsatser innehållade ordet CDM.
1. Gravitational Collapse of a Massless Scalar Field in a Theory of Minimally Modified Gravity
Master-uppsats, KTH/FysikSammanfattning : This thesis explores the spherically symmetric gravitational collapse of a massless scalar field in a minimally modified gravity theory denoted VCDM (V replaces $\Lambda$ in the $\Lambda$CDM abbreviation), a class of theories propagating the same degrees of freedom as general relativity at the expense of broken 4D diffeomorphism invariance. Numerical evolution of the equations of motion reveals that for small initial scalar profile amplitudes, no black hole forms from the collapse. LÄS MER
2. Finding new members of the VelHel-4 stream
Kandidat-uppsats, KTH/Skolan för teknikvetenskap (SCI)Sammanfattning : According to the paradigm of lambda-CDM cosmology, the stellar halo ofour Galaxy has been built-up over time through the accretion of other galaxiesand star clusters. The remnants of some of these are still observable today asstellar streams, but are typically very faint and difficult to resolve amidst the farmore numerous foreground Milky Way stars. LÄS MER
3. Warm dark matter simulations and 21cm astronomy
Kandidat-uppsats, Uppsala universitet/Institutionen för fysik och astronomiSammanfattning : The recent boom in 21cm astronomy has piqued the interest of many, especially cosmologists realizing its applications in their field. This study aims to determine if 21cm astronomy is a good tool for testing the validity of keV WDM models, as well as creating a code capable of simulating keV WDM models from an existing CDM code. LÄS MER
4. Thawing, Scaling and Tracking QUintessence in a Phase Space Perspective : and comparisons to the ΛCDM model
Kandidat-uppsats, Karlstads universitet/Institutionen för ingenjörsvetenskap och fysik (from 2013)Sammanfattning : This thesis aims to give an introduction to quintessence models as well ascomparing those models with the currently accepted ΛCDM model. We willconsider quintessence in a spatially flat and isotropic Universe and useregular dynamical systems on a bounded three dimensional phase spacewhere we perform numerical calculations. LÄS MER
5. Starbursts at Cosmic Dawn : Formation of Globular Clusters, Ultra-Faint Dwarfs, and Population III star clusters at z > 6
Master-uppsats, Stockholms universitet/Institutionen för astronomiSammanfattning : In the standard model of cosmology (ΛCDM) the first stars, star clusters, and galaxies are expected to have formed in short bursts of star formation in low-mass dark matter halos at high redshifts (). Up to this point, attempts to predict the properties and abundances of these luminous objects have made use of numerically expensive cosmological simulations. LÄS MER