Résumé |
In the usual approach to Conformal Bootstrap a 4-point function is expanded in conformal
blocks and crossing symmetry is imposed as a constraint. However one can use an
alternative basis of expansion, which is crossing symmetric to begin with. This new basis
turns out to comprise Witten diagrams, and the constraint equations come from consistency
with the usual operator product expansion. The new equations give precise analytic results
in various CFTs, including the Wilson-Fisher fixed point, large N vector model, or a CFT with
large spin operators. I will show how to construct this formalism, and how the Mellin space is
a natural candidate for this setup. Then I will illustrate how to get OPE data with this
approach. I will conclude commenting on some inherent ambiguities of this basis which pose
limitations to this approach, and finally how to fix them. |