Tracing the gravitational potential using cosmic voids

Understand

The properties of large underdensities in the distribution of galaxies in the Universe, known as cosmic voids, are potentially sensitive probes of fundamental physics.

• We use data from the MultiDark suite of N-body simulations and multiple halo occupation distribution mocks to study the relationship between galaxy voids, identified using a watershed void-finding algorithm, and the gravitational potential $\Phi$.
• We find that the majority of galaxy voids correspond to local density minima in larger-scale overdensities, and thus lie in potential wells.
• However, a subset of voids can be identified that closely trace maxima of the gravitational potential and thus stationary points of the velocity field.