Colloquium on Aug. 28th, 2019

Model-independent strong gravitational lensing and its applications in cosmology and galaxy evolution

Speaker: Jenny Wanger (Heidelberg University)

Venue: Room 2111, SWIFAR Building

Time: 3:00 PM, Wednesday, 28th August, 2019

Abstract: 

Strong gravitational lenses can map an extended background source to several highly distorted and magnified images. Analysing the properties of those images yields important information about the distribution of the deflecting mass and the background source. In this way, we can trace dark matter and we can investigate old, faint, and distant galaxies in the early universe. In addition, strong gravitational lensing of time-varying sources is used to determine parameters of the cosmological model, especially the Hubble-Lemaître constant. We develop a new approach to infer local properties of the gravitational lens and to reconstruct the source only using the properties of the multiple images without assuming a lens or a source model. In the talk, I will introduce the method and its applications in comparison to standard lens modelling methods. Our approach will be very useful for upcoming sky surveys like EUCLID because they require highly automated and robust evaluation methods and a fast data processing.