We investigate the local and line-of-sight overdensities of strong gravitational lens galaxies using wide-area multiband imaging from the Hyper Suprime-Cam Subaru Strategic Program .
We present 41 new definite or probable lens candidates discovered in Data Release 2 of the survey .
Using a combined sample of 87 galaxy-scale lenses out to a lens redshift of z _ { \mathrm { L } } \sim 0.8 , we compare galaxy number counts in lines of sight toward known and newly-discovered lenses in the survey to those of a control sample consisting of random lines of sight .
We also compare the local overdensity of lens galaxies to a sample of “ twin ” galaxies that have a similar redshift and velocity dispersion to test whether lenses lie in different environments from similar non-lens galaxies .
We find that lens fields contain higher number counts of galaxies compared to the control fields , but this effect arises from the local environment of the lens .
Once galaxies in the lens plane are removed , the lens lines of sight are consistent with the control sample .
The local environments of the lenses are overdense compared to the control sample , and are slightly overdense compared to those of the twin sample , although the significance is marginal .
There is no significant evidence of the evolution of the local overdensity of lens environments with redshift .