Optimal void finders in weak lensing maps
  Cosmic voids are a key component of the large-scale structure that contain a
plethora of cosmological information. Typically, voids are identified from the
underlying galaxy distribution, which is a biased tracer of the total matter
field. Previous works have shown that 2D voids identified in weak lensing maps
-- weak lensing voids -- correspond better to true underdense regions along the
line of sight. In this work, we study how the properties of weak lensing voids
depend on the choice of void finder, by adapting several popular void finders.
We present and discuss the differences between identifying voids directly in
the convergence maps, and in the distribution of weak lensing peaks. Particular
effort has been made to test how these results are affected by galaxy shape
noise, which is a dominant source of noise in weak lensing observations. By
studying the signal-to-noise ratios (SNR) for the tangential shear profile of
each void finder, we find that voids identified directly in the convergence
maps have the highest SNR but are also the ones most affected by galaxy shape
noise. Troughs are least affected by noise, but also have the lowest SNR. The
tunnel algorithm, which identifies voids in the distribution of weak lensing
peaks, represents a good compromise between finding a large tangential shear
SNR and mitigating the effect of galaxy shape noise.
