Line Operator Index on S1 × S3

A bstract We derive a general formula of an index for superconformal field theories on S 1 × S 3 with insertions of BPS Wilson line or ’t Hooft line operator at the north pole and their anti-counterpart at the south pole of S 3 . One-loop and monopole bubbling effects are taken into account in the computation. As examples, we calculate the indices for theories and SU(2) theory with N f = 4, and find good agreements between indices of line operators related by S-duality. The relation between Verlinde loop operators and the indices is explored. The holographic correspondence between the fundamental (anti- symmetric) Wilson line operator and the fundamental string (D5 brane) in AdS5 × S 5 is confirmed by the index comparison.