  We investigate the width of the flux tube between heavy static quark charges.
Using the gauge/gravity duality, we find the properties of the minimal
connected surface related to the width of the bound state. We show that in the
confining phase, the logarithmic broadening predicted by the effective string
description and observed in lattice simulations is a generic property of all
confining backgrounds. We also study the transverse fluctuations of the string
connecting two static quarks in curved backgrounds. Our formalism is applied to
AdS space where we compute the expectation value of the square of transverse
deviations of the string, a quantity related to the width.
