Dilute two dimensional interacting quantum fluids

The statistical mechanics of submonolayer helium films on graphite substrates are conventionally described by site localization models. However, dynamical experiments indicate high mobility so that a solid state band picture might be more appropriate. As a theoretical test case, the authors consider dilute two dimensional hard core quantum fluids and find logarithmic divergences not present in the well known three dimensional counterparts. These divergences are not a serious obstacle to band theoretical models which include interactions. (Auth.)