Theory HEP Seminar

The trouble with spatial curvature

Sunny Vagnozzi

Kavli Institute for Cosmology, IoA, Cambridge

The latest results from the Planck satellite appear to prefer a spatially closed Universe, with curvature parameter Ωk<0, at high significance. If true, this could represent a big problem for the extremely successful inflationary paradigm. I will explain why the so-called “geometrical degeneracy” makes this result not reliable. I will show that in order to obtain a reliable measurement of spatial curvature it is necessary to break this geometrical degeneracy, and will illustrate enormous difficulties towards doing so in a consistent way. Building on my recent work, I will show that it is still possible to overcome these obstacles and confidently assert that the Universe is spatially flat at least to the Ωk~10^-2 level