文档介绍：UCLEAR PHYSIC~
PROCEEDINGS
SUPPLEMENTS
Nuclear Physics B (Proc. Suppl.) 43 (1995) 299 302
Does COBE rule out a toroidal Universe?
Angelica de Oliveira-Costa 1'2 and e F. Smoot 1
1Lawrence Berkeley Laboratory, Space Sciences Laboratory and Center for Particle Astrophysics,
Building 50-205, University of California, Berkeley CA, 94720.
2Instituto Nacional de Pesquisas Espaciais (INPE), Astrophysics Division, Sgo Jos~ dos Campos, Sgo
Paulo 12227-010, Brazil.
The cosmic microwave background (CMB) is a unique probe of cosmological parameters and conditions. There
is a connection between anisotropy in the CMB and the topology of the Universe. Adopting a universe with the
topology of a 3-Torus, or a universe where only harmonics of the fundamental mode are allowed, and using 2-years
of COBE/DMR data, we obtain constraints on the topology of the Universe. We obtain more accurate results
than previous work by using all multipole moments, avoiding approximations puting their full covariance
matrix. The best fit for a cubic toroidal universe is obtained at a scale of 7200h -1Mpc for n = 1. The data set a
lower limit on the cell size of 4320h -1Mpc at 95% confidence and 5880h -1Mpc at 68% confidence. These results
show that the most probable cell size would be around times larger than the horizon scale, implying that the
3-Torus topolog