  We demonstrate that the low-energy effective theory for a deconfined quantum
critical point in $d=2+1$ dimensions contains a leading order contribution
given by the Faddeev-Skyrme model. The Faddeev-Skyrme term is shown to give
rise to the crucial Maxwell term in the CP$^1$ field theory governing the
deconfined quantum critical point. We derive the leading contribution to the
spin stiffness near the quantum critical point and show that it exhibits a
logarithmic correction to scaling of the same type as recently observed
numerically in low dimensional models of quantum spin systems featuring a
quantum critical point separating an antiferromagnetically ordered state from a
valence bond solid state. These corrections, appearing away from upper or lower
critical dimensions, reflect an emergent gauge symmetry of low-dimensional
antiferromagnetic quantum spin systems.
