z~2.3 cosmic voids in the COSMOS field

We used a 3D tomographic map of the absorption with an effective comoving spatial resolution of 2.5h^-1^Mpc and a volume of 3.15x10^5^h^-3^Mpc^3^, which was reconstructed from moderate-resolution Keck I/LRIS spectra of 240 background Lyman-break galaxies and quasars in a 0.16deg^2^ footprint in the COSMOS field.

Voids were detected using a spherical overdensity finder calibrated from hydrodynamical simulations of the intergalactic medium (IGM). This allows us to identify voids in the IGM corresponding to voids in the underlying matter density field, yielding a consistent volume fraction of voids in both data (19.5%) and simulations (18.2%). We fit excursion set models to the void radius function and compare the radially averaged stacked profiles of large voids (r>5h^-1^Mpc) to stacked voids in mock observations and the simulated density field.