The view from the boundary: a new void stacking method

Understand

We introduce a new method for stacking voids and deriving their profile that greatly increases the potential of voids as a tool for precision cosmology.

• Given that voids are highly non-spherical and have most of their mass at their edge, voids are better described relative to their boundary rather than relative to their centre, as in the conventional spherical stacking approach.
• The boundary profile is obtained by computing the distance of each volume element from the void boundary.
• Voids can then be stacked and their profiles computed as a function of this boundary distance.