17 citations · 33 across the 5 of their papers we have counts for
5 papers
Evolution in the Lyman-alpha forest
Thomas Liebscher, Rainer Kayser, Phillip Helbig
We reanalyse the spectra used by D.-E. Liebscher (no relation) et al with the same goal -- determining the cosmological parameters -- and basically the same assumptions but with a…
A general and practical method for calculating cosmological distances
Rainer Kayser, Phillip Helbig, Thomas Schramm
The calculation of distances is of fundamental importance in extragalactic astronomy and cosmology. However, no practical implementation for the general case has previously been av…
The light curve and the time delay of QSO 0957+561
Jaan Pelt, Rainer Kayser, Sjur Refsdal +1
We present a new analysis of the presently available photometric data for the gravitationally lensed quasar 0957+561 A,B with the aim of determining the time delay between its two…
Cosmological parameters and the redshift distribution of gravitational lenses
Phillip Helbig, Rainer Kayser
For known gravitational lens systems the redshift distribution of the lenses is compared with theoretical expectations for ~Friedmann-Lema\^ıtre~cosmological models, which…
The complex theory of gravitational lensing: Beltrami equation and cluster lensing
T. Schramm, R. Kayser
We introduce a new complex formalism to describe arclet fields in clusters of galaxies and derive the appropriate inversion techniques to find the related mass distribution of the…