We use properties of void populations identified in N -body simulations to forecast the ability of upcoming galaxy surveys to differentiate models of f ( R ) gravity from \Lambda CDM cosmology .
We analyze multiple simulation realizations , which were designed to mimic the expected number densities , volumes , and redshifts of the upcoming Euclid satellite and a lower-redshift ground-based counterpart survey , using the public VIDE toolkit .
We examine void abundances , ellipicities , radial density profiles , and radial velocity profiles at redshifts 1.0 and 0.43 .
We find that stronger f ( R ) coupling strengths eliminates small voids and produces voids up to \sim 20 \% larger in radius , leading to a significant tilt in the void number function .
Additionally , under the influence of modified gravity , voids at all scales tend to be measurably emptier with correspondingly higher compensation walls .
The velocity profiles reflect this , showing increased outflows inside voids and increased inflows outside voids .
Using the void number function as an example , we forecast that future surveys can constrain the modified gravity coupling strength to \sim 3 \times 10 ^ { -5 } using voids .