A dispersion relation for defect CFT
Julien Barrat, Aleix Gimenez-Grau, Pedro Liendo
Abstract
A bstract We present a dispersion relation for defect CFT that reconstructs two-point functions in the presence of a defect as an integral of a single discontinuity. The main virtue of this formula is that it streamlines explicit bootstrap calculations, bypassing the resummation of conformal blocks. As applications we reproduce known results for monodromy defects in the epsilon-expansion, and present new results for the supersymmetric Wilson line at strong coupling in $$ \mathcal{N} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>N</mml:mi> </mml:math> = 4 SYM. In particular, we derive a new analytic formula for the highest R -symmetry channel of single-trace operators of arbitrary length.