R. Kayser

Publication List Details

Period

1988 - 2000

Number

10

Co-Authors

A cosmological test with compact radio sources (1994)

Kayser, R.

The recent proposal by Kellermann (1993) to use the angular size/redshift relation of compact radio sources to obtain information on the value of cosmological parameters has provoked considerable...

The complex theory of gravitational lensing: Beltrami equation and cluster lensing (1994)

Schramm, T., Kayser, R.

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 lensing cluster....

Radial cluster lensing: A simple differential equation describing arclet fields (1994)

Schramm, T., Kayser, R.

Clusters of galaxies acting as gravitational lenses deform the images of background galaxies. For small galaxies the deformation is determined by the local properties of the lens (shear,...

Time delay controversy on QSO 0957+561 not yet decided (1994)

Pelt, J., Hoff, W., Kayser, R., Refsdal, S., Schramm, T.

We present a new analysis of previously published optical and radio data sets of the gravitationally lensed quasar 0957+561 A,B with the aim of determining the time delay between its two images. We...

New observations and gravitational lens models of the Cloverleaf quasar H1413 + 117 (1990)

Kayser, R, Surdej, Jean, Condon, J J, Kellermann, K I, Magain, Pierre, Remy, M, ...

New optical and radio observations of the quadruple quasar H1413 + 117, the Cloverleaf, are presented. VLA data show radio counterparts at the positions of the four optical images and an additional...

Profiles of a Key Programme: Gravitational Lensing (1989)

Surdej, Jean, Arnaud, J, Borgeest, U, Djorgovski, S, Fleischmann, F, Hammer, F, ...

Prior to Professor van der Laan's enquiry, in the March 1988 issue of the Messenger, on the general interest among astronomers from the European community to possibly participate in Key Programmes...

Partial rupture of the proximal Achilles tendon: a differential diagnostic problem in ultrasound imaging

Kayser, R, Mahlfeld, K, Heyde, C, Tschauner, C

Objectives: The aim of this study was to determine whether ultrasound can correctly visualise partial ruptures of the proximal Achilles tendon.