Master symmetry for holographic Wilson loops

We identify the symmetry underlying the recently observed spectral-parameter transformations of holographic Wilson loops alias minimal surfaces in AdS/CFT. The generator of this nonlocal symmetry is shown to furnish a raising operator on the classical Yangian-type charges of symmetric coset models. We explicitly demonstrate how this master symmetry acts on strong-coupling Wilson loops and indicate a possible extension to arbitrary coupling.

Figure 1

Sequence of master transformations for parameter values $\theta =0,\frac{3\pi }{16},\frac{3\pi }{4},\pi$ applied to discrete minimal surfaces bounded by an ellipse and a triangle at $y=\frac{1}{10}$.