On Determining the Topology of the Observable Universe via threedimensional Quasar Positions
Abstract
Hot big bang cosmology says nothing about the topology of the Universe. A topologyindependent algorithm is presented which is complementary to that of Lehoucq, Luminet & LachiezeRey, and which searches for evidence of multiconnectedness using catalogues of astrophysically observed objects. The basis of this algorithm is simply to search for a quintuplet of quasars (over a region of a few hundred comoving Mpc) which can be seen in two different parts of our past time cone, allowing for a translation, an arbitrary rotation and possibly a reflection. This algorithm is demonstrated by application to the distribution of quasars between redshifts of z=1 and z~4, i.e. at a comoving distance from the observer of 1700h^1d3300h^1 Mpc. Two pairs of isometric quintuplets separated by more than 300h^1 Mpc are found. This is consistent with the number expected from Monte Carlo simulations in a simply connected universe if the detailed anisotropy of sky coverage by the individual quasar surveys is taken into account. The linear transformation in (flat) comoving space from one quintuplet to another requires translations of 353h^1 and 4922h^1 Mpc respectively, plus a reflection in the former case, and plus both a rotation and a reflection in the latter. Since reflections are required, if these two matches were due to multiconnectedness then the Universe would be nonorientable.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 December 1996
 DOI:
 10.1093/mnras/283.4.1147
 arXiv:
 arXiv:astroph/9603052
 Bibcode:
 1996MNRAS.283.1147R
 Keywords:

 METHODS: OBSERVATIONAL;
 QUASARS: GENERAL;
 COSMOLOGY: OBSERVATIONS;
 LARGESCALE STRUCTURE OF UNIVERSE;
 Astrophysics;
 General Relativity and Quantum Cosmology
 EPrint:
 6 pages, including Figures 2,3