Comment on "A Supervoid Imprinting the Cold Spot in the Cosmic Microwave Background"

Understand

Recently Finelli et al.

• [http://arxiv.org/abs/1405.1555] found evidence for a relatively nearby (z = 0.16) void in a galaxy catalogue in the direction of the cosmic microwave background (CMB) Cold Spot.
• Using a perturbative calculation, they also claimed that such a void would produce a CMB decrement comparable to that of the observed Cold Spot, mainly via the nonlinear Rees-Sciama effect.
• Here I calculate the effect of such a void using a fully general relativistic model and show that, to the contrary, the linear integrated Sachs-Wolfe effect dominates and produces a substantially weaker decrement than observed.