One-point functions in 2D and 4D SUSY Janus

TL;DR

This paper computes one-point functions in 2D and 4D SUSY Janus interfaces, comparing supergravity and CFT results, and finds exact agreement only for half-BPS cases, highlighting the special role of maximal supersymmetry.

Contribution

It extends calculations of one-point functions in holographic Janus interfaces and analyzes the conditions for exact weak/strong coupling agreement across different SUSY setups.

Findings

Exact agreement occurs only for half-BPS interfaces.

For other interfaces, agreement is only to first order in the jump parameter.

Maximally supersymmetric interfaces uniquely exhibit exact weak/strong coupling matching.

Abstract

We calculate the one-point functions of the marginal operator $\mathcal{L}'$ dual to the space-varying dilaton in 4D and 2D holographic Janus interfaces, extending results in arXiv:hep-th/0407073. We compare strongly-coupled supergravity and weakly-coupled CFT limits across $\mathcal{N}=0, 1, 2, 4$ holographic Janus interfaces in 4D SYM, and $\mathcal{N}=0, 4$ Janus interfaces for 2D D1-D5 CFT. Exact agreement between these regimes occurs only for the half-BPS interfaces in both 4D and 2D cases, while for other interfaces they agree to first order of the jump parameter. This result reinforces that exact weak/strong coupling matching for interface observables on supersymmetric (SUSY) conformal manifolds is exclusive to maximally SUSY interfaces.