Relatore
Descrizione
We consider circular Wilson loops in a defect version of N=4 super-Yang-Mills theory
which is dual to the D5-D3 brane system. When the loops are parallel to the defect, we
can construct both BPS and non-BPS operators. At strong 't Hooft coupling we observe,
in the non-BPS case, a Gross-Ooguri-like phase transition in the dual gravitational theory:
the familiar disk solution dominates when the operator is far from the defect while a
cylindrical string worldsheet, connecting the boundary loop with the probe D5-brane, is
favourite below a certain distance. In the BPS case, the cylindrical solution does not exist
for any choice of the physical parameters, suggesting that light-modes supergravity
exchanges with the disk solution always saturate the expectation value at strong coupling.
We study the double-scaling limit for large k and large 't Hooft coupling that allow us to
compare perturbative and non-perturbative results.
