Monte-Carlo studies on IR conformality and emergence of mass-gap in 2+1 dimensional field theories

Gauge theories in 2+1 dimensions are simple but powerful systems to understand the emergence of mass-gap and hadron spectrum in QCD-like theories that describe our 3+1 dimensional world.  Recently, these 2+1 dimensional systems have attracted even more attention due to conjectured dualities between seemingly very different theories that could flow to the same fixed point. In this talk, I will present results from our numerical studies on the infrared behaviors of 2+1 dimensional Abelian and non-Abelian gauge theories coupled to many flavors of massless fermions using lattice regularization.