Paper: astro-ph/0304290 From: Stephen Weatherley stephen.weatherley@imperial.ac.uk Date: Tue, 15 Apr 2003 20:02:03 GMT (254kb)
Title: Ghosts of the Milky Way: a search for topology in new quasar catalogues Authors: S.J. Weatherley (1), S.J. Warren (1), S.M. Croom (2), R.J. Smith (3), B.J. Boyle (2), T. Shanks (4), L. Millar (5), M.P. Baltovic (1) ((1) Imperial College London, (2) AAO, (3) Liverpool John Moores, (4) Durham, (5) Oxford) Comments: MNRAS Letters, Accepted, 5 pages, 3 figures \ We revisit the possibility that we inhabit a compact multi-connected flat, or nearly-flat, Universe. Analysis of COBE data has shown that, for such a case, the size of the fundamental domain must be a substantial fraction of the horizon size. Nevertheless, there could be several copies of the Universe within the horizon. If the Milky Way was once a quasar we might detect its `ghost' images. Using new large quasar catalogues we repeat the search by Fagundes & Wichoski for antipodal quasar pairs. By applying linear theory to account for the peculiar velocity of the local group, we are able to narrow the search radius to 134 arcsec. We find seven candidate antipodal quasar pairs within this search radius. However, a similar number would be expected by chance. We argue that, even with larger quasar catalogues, and more accurate values of the cosmological parameters, it is unlikely to be possible to identify putative ghost pairs unambiguously, because of the uncertainty of the correction for peculiar motion of the Milky Way. \ ( http://de.arXiv.org/abs/astro-ph/0304290 , 254kb) ------------------------------------------------------------------------------
At first sight it's rather a dicouraging result - see the last sentence above. :-( but...
Let's explore other approaches! :-)
Thanks Andrzej!
About two years ago, when I nearly got a job at home, Gary Mamon pointed out that cosmic topology was "heretical" (po polsku "heresia") when I first started working on the subject, but thanks to work by me and others, had become "tolerated".
I guess it's now becoming... "fashionable". So we'd better start publishing. :)
b
On Thu, 17 Apr 2003, Andrzej Marecki wrote:
Paper: astro-ph/0304290 From: Stephen Weatherley stephen.weatherley@imperial.ac.uk Date: Tue, 15 Apr 2003 20:02:03 GMT (254kb)
Title: Ghosts of the Milky Way: a search for topology in new quasar catalogues Authors: S.J. Weatherley (1), S.J. Warren (1), S.M. Croom (2), R.J. Smith (3), B.J. Boyle (2), T. Shanks (4), L. Millar (5), M.P. Baltovic (1) ((1) Imperial College London, (2) AAO, (3) Liverpool John Moores, (4) Durham, (5) Oxford) Comments: MNRAS Letters, Accepted, 5 pages, 3 figures \ We revisit the possibility that we inhabit a compact multi-connected flat, or nearly-flat, Universe. Analysis of COBE data has shown that, for such a case, the size of the fundamental domain must be a substantial fraction of the horizon size. Nevertheless, there could be several copies of the Universe within the horizon. If the Milky Way was once a quasar we might detect its `ghost' images. Using new large quasar catalogues we repeat the search by Fagundes & Wichoski for antipodal quasar pairs. By applying linear theory to account for the peculiar velocity of the local group, we are able to narrow the search radius to 134 arcsec. We find seven candidate antipodal quasar pairs within this search radius. However, a similar number would be expected by chance. We argue that, even with larger quasar catalogues, and more accurate values of the cosmological parameters, it is unlikely to be possible to identify putative ghost pairs unambiguously, because of the uncertainty of the correction for peculiar motion of the Milky Way. \ ( http://de.arXiv.org/abs/astro-ph/0304290 , 254kb)
At first sight it's rather a dicouraging result - see the last sentence above. :-( but...
Let's explore other approaches! :-)
-- Andrzej
-
Andrzej Marecki -
shape-univ＠astro.uni.torun.pl