In between the Cosmic Microwave Background (CMB) and the instrument there are other sources of radiation, called foregrounds. The foregrounds radiate in the same frequency bands as the background, and cause contamination ...

Observations of the Cosmic Microwave Background is impaired by other astrophysical sources that also radiate in the microwave spectrum. These other, non-CMB sources are known as foregrounds. In this thesis, three different ...

During inflation, the potential of the inflaton scalar field $\phi$, drives the exponential expansion of the Universe. The nature of the inflaton potential is presently unknown, but one hopes to learn more from observations ...

Gravitational lensing has played an important role in cosmology since the discovery of the first gravitational lensing system in 1979 (Walsh et al.), where the quasar QSO 0957+561 can be seen in two images. Such multiple ...

The thesis examines the relation between the magnetic field as measured by MDI and the continuum intensity at four different wavelengths (1319, 1199, 1037 and 910Å) as measured by SUMER. A method for copointing the instruments ...

It is believed that the Broad Emission Line Region of Quasars consists of discrete clouds. Due to the suspected small size of a cloud, the radiation from clouds may be strongly amplified by gravitational microlensing. It ...