The Color Flux Tube as an Effective String

We investigate the low-energy regime of the confining string connecting color sources in Yang-Mills theory. First, we present results of the Monte Carlo measurement of the width of the flux tube between two static quarks in the fundamental representation both at zero and at finite temperature. Then we consider the confining flux tube connecting color sources in larger representations of the gauge group. For stable strings - the k-strings - we study the Luscher term; for unstable strings we investigate their decay as the distance between the static sources is increased.