The DES view of the Eridanus supervoid and the CMB Cold Spot
  The Cold Spot is a puzzling large-scale feature in the Cosmic Microwave
Background temperature maps and its origin has been subject to active debate.
As an important foreground structure at low redshift, the Eridanus supervoid
was recently detected, but it was subsequently determined that, assuming the
standard $\Lambda$CDM model, only about 10-20$\%$ of the observed temperature
depression can be accounted for via its Integrated Sachs-Wolfe imprint.
However, $R\gtrsim100~h^{-1}\mathrm{Mpc}$ supervoids elsewhere in the sky have
shown ISW imprints $A_{\mathrm{ISW}}\approx5.2\pm1.6$ times stronger than
expected from $\Lambda$CDM ($A_{\mathrm{ISW}}=1$), which warrants further
inspection. Using the Year-3 redMaGiC catalogue of luminous red galaxies from
the Dark Energy Survey, here we confirm the detection of the Eridanus supervoid
as a significant under-density in the Cold Spot's direction at $z<0.2$. We also
show, with $\mathrm{S/N}\gtrsim5$ significance, that the Eridanus supervoid
appears as the most prominent large-scale under-density in the dark matter mass
maps that we reconstructed from DES Year-3 gravitational lensing data. While we
report no significant anomalies, an interesting aspect is that the amplitude of
the lensing signal from the Eridanus supervoid at the Cold Spot centre is about
$30\%$ lower than expected from similar peaks found in N-body simulations based
on the standard $\Lambda$CDM model with parameters $\Omega_{\rm m} = 0.279$ and
$\sigma_8 = 0.82$. Overall, our results confirm the causal relation between
these individually rare structures in the cosmic web and in the CMB, motivating
more detailed future surveys in the Cold Spot region.
