ABSTRACT
The shortest distance around the Universe through us is unlikely to be much larger than the horizon diameter if microwave background anomalies are due to cosmic topology. We show that observational constraints from the lack of matched temperature circles in the microwave background leave many possibilities for such topologies. We evaluate the detectability of microwave background multipole correlations for sample cases. Searches for topology signatures in observational data over the large space of possible topologies pose a formidable computational challenge.
ABSTRACT
We show how a characteristic length scale imprinted in the galaxy two-point correlation function, dubbed the "linear point," can serve as a comoving cosmological standard ruler. In contrast to the baryon acoustic oscillation peak location, this scale is constant in redshift and is unaffected by nonlinear effects to within 0.5 percent precision. We measure the location of the linear point in the galaxy correlation function of the LOWZ and CMASS samples from the Twelfth Data Release (DR12) of the Baryon Oscillation Spectroscopic Survey (BOSS) Collaboration. We combine our linear-point measurement with cosmic-microwave-background constraints from the Planck satellite to estimate the isotropic-volume distance D_{V}(z), without relying on a model-template or "reconstruction" method. We find D_{V}(0.32)=1264±28 Mpc and D_{V}(0.57)=2056±22 Mpc, respectively, consistent with the quoted values from the BOSS Collaboration. This remarkable result suggests that all the distance information contained in the baryon acoustic oscillations can be conveniently compressed into the single length associated with the linear point.