Integral relations for arbitrary AdS vertex-function topologies

Formulate integral relations between $(n-1)$-point and $n$-point AdS vertex functions for every topology of AdS vertex functions, thereby enabling application of the reduction technique to arbitrary $n$-point AdS Feynman diagrams.

Background

The reduction technique recursively decomposes an nn-point AdS Feynman diagram by expressing it in terms of (n−1)(n-1)-point diagrams and then converting integrals of (n−1)(n-1)-point AdS vertex functions into nn-point AdS vertex functions. The paper establishes the required relations for the comb channel and derives a five-point relation involving a modified propagator, which suffices for the five-point examples and can be extended recursively to certain diagrams composed entirely of cubic vertices.

For arbitrary nn-point topologies, however, the necessary integral relations have not been formulated. Developing such relations would extend the reduction technique beyond the comb-channel and recursively tractable cubic cases to general AdS Feynman diagrams.

References

Looking ahead, the application of the reduction technique to the $n$-point diagrams in the comb channel composed entirely of cubic vertices can be carried out straightforwardly. Its application to an arbitrary $n$-point diagram requires the formulation of the integral relations between the $(n-1)$-point and the $n$-point AdS vertex functions. Ultimately, it is expected that these relations can be found for any topology of AdS vertex functions which we leave for future work.

— Reduction technique for expanding the Feynman diagrams in AdS$_2$  (2609.29306 - Khiteev, 24 Sep 2026) in Section Conclusion (Section 5)