The sizes of mini-voids in the local universe: an argument in favor of a warm dark matter model?

Understand

Using high-resolution simulations within the Cold and Warm Dark Matter models we study the evolution of small scale structure in the Local Volume, a sphere of 8 Mpc radius around the Local Group.

• We compare the observed spectrum of mini-voids in the Local Volume with the spectrum of mini-voids determined from the simulations.
• We show that the \LWDM model can easily explain both the observed spectrum of mini-voids and the presence of low-mass galaxies observed in the Local Volume, provided that all haloes with circular velocities greater than 20 km/s host galaxies.
• On the contrary within the LCDM model the distribution of the simulated mini-voids reflects the observed one if haloes with maximal circular velocities larger than 35 km/s host galaxies.