High redshift structures and the geometry of the universe |
| |
| Authors: | Steven Phillipps |
| |
| Institution: | (1) Astrophysics Group, Department of Physics, University of Bristol, Tyndall Avenue, BS8 1TL Bristol |
| |
| Abstract: | The geometry of space at high redshifts is dependent on the value of the cosmological constant  (or its normalised contribution to the curvature of space,  0). Here we investigate the prospects for constraining 0 from the apparent dimensions of structures seen at very highz. As an example we consider the single highest redshift structure currently known, atz=3.4. We show that there can be substantial differences in apparent orientation, depending on the cosmological model assumed, in particular the radial stretching at highz can lead to structures inprobably well aligned with the line of sight if we (incorrectly) assume a large value of 0. In our example we are limited by the effect of the (unknown) dynamics within this cluster/supercluster. However, a suitably well defined, relatively small, sample of large structures at highz, along with a study of their velocity fields, may provide an alternative, and complementary, approach to the use of very large statistical samples as required by previously suggested methods. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
