It is well-known that galaxy environment has a fundamental effect in shaping its properties .
We study the environmental effects on galaxy evolution , with an emphasis on the environment defined as the local number density of galaxies .
The density field is estimated with different estimators ( weighted adaptive kernel smoothing , 10 ^ { th } and 5 ^ { th } nearest neighbors , Voronoi and Delaunay tessellation ) for a K _ { s } < 24 sample of \sim 190,000 galaxies in the COSMOS field at 0.1 < z < 3.1 .
The performance of each estimator is evaluated with extensive simulations .
We show that overall , there is a good agreement between the estimated density fields using different methods over \sim 2 dex in overdensity values .
However , our simulations show that adaptive kernel and Voronoi tessellation outperform other methods .
Using the Voronoi tessellation method , we assign surface densities to a mass complete sample of quiescent and star-forming galaxies out to z \sim 3 .
We show that at a fixed stellar mass , the median color of quiescent galaxies does not depend on their host environment out to z \sim 3 .
We find that the number and stellar mass density of massive ( > 10 ^ { 11 } M _ { \odot } ) star-forming galaxies have not significantly changed since z \sim 3 , regardless of their environment .
However , for massive quiescent systems at lower redshifts ( z \lesssim 1.3 ) , we find a significant evolution in the number and stellar mass densities in denser environments compared to lower density regions .
Our results suggest that the relation between stellar mass and local density is more fundamental than the color-density relation and that environment plays a significant role in quenching star formation activity in galaxies at z \lesssim 1 .