QCD flux tube in AdS
Color flux tube is an object crucial for confinement of quarks and gluons in non-abelian gauge theories like QCD. Flux tubes can be understood in terms of an effective theory for long strings, and they have been also studied on the lattice. Combination of these approaches, in particular, lead to discovery of massive modes localized on the flux tube worldsheet, notably of the worldsheet axion. Despite this progress little is understood about the connection between the effective theory and microscopic degrees of freedom of the gauge theories. We propose that placing a confining gauge theory on a rigid AdS background can be an efficient method for establishing this connection. AdS works as an IR regulator which for a small AdS radius renders the theory weakly coupled, at the same time, at large radius we recover confinement in flat space.