Investigating the Dark Universe through Gravitational Lensing
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
A variety of precision observations suggest that the present universe is dominated by some unknown components, the so-called dark matter and dark energy. The distribution and properties of these components are the focus of modern cosmology and we are only beginning to understand them.
Gravitational lensing, the bending of light in the gravitational field of a massive object, is one of the predictions of the general theory of relativity. It has become an ever more important tool for investigating the dark universe, especially with recent and coming advances in observational data.
This thesis studies gravitational lensing effects on scales ranging over ten orders of magnitude to probe very different aspects of the dark universe. Implementing a matter distribution following the predictions of recent simulations, we show that microlensing by a large population of massive compact halo objects (MACHOs) is unlikely to be the source of the observed long-term variability in quasars. We study the feasibility of detecting the so far elusive galactic dark matter substructures, the so-called “missing satellites”, via millilensing in galaxies close to the line-of-sight to distant light sources. Finally, we utilise massive galaxy clusters, some of the largest structures known in the universe, as gravitational telescopes in order to detect distant supernovae, thereby gaining insight into the expansion history of the universe. We also show, how such observations can be used to put constraints on the dark matter component of these galaxy clusters.
Place, publisher, year, edition, pages
Stockholm: Department of Astronomy, Stockholm University , 2011. , 67 p.
cosmology, gravitational lensing, dark matter, galaxies, galaxy clusters
Astronomy, Astrophysics and Cosmology
Research subject Astronomy
IdentifiersURN: urn:nbn:se:su:diva-56515ISBN: 978-91-7447-281-3 (print)OAI: oai:DiVA.org:su-56515DiVA: diva2:411704
2011-06-01, lecture room FD5, AlbaNova universitetscentrum, Roslagstullsbacken 21, Stockholm, 13:15 (English)
Wambsganss, Joachim, Professor
Goobar, Ariel, ProfessorMörtsell, Edvard, DrZackrisson, Erik, Dr
At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 6: Submitted. 2011-05-102011-04-192011-05-16Bibliographically approved
List of papers