New Restrictions on Spatial Topology of the Universe from Microwave Background Temperature Fluctuations

If the Universe has the topology of a 3-torus ($T^3$), then it follows from recent data on large-scale temperature fluctuations $\mathrm{\Delta }T\mathrm{/}T$ of the cosmic microwave background that either the minimal size of the torus is at least of the order of the present cosmological horizon, or the large-scale $\mathrm{\Delta }T\mathrm{/}T$ pattern should have a symmetry plane (in case of the effective $T^1$ topology) or a symmetry axis (in case of the effective $T^2$ topology), the latter possibility being probably excluded by the data.