• DOI:10.1007/JHEP05(2020)075
• Corpus ID: 210718455

Holographic RG flows for Kondo-like impurities

@article{Erdmenger2020HolographicRF,
  title={Holographic RG flows for Kondo-like impurities},
  author={Johanna Erdmenger and Charles M. Melby-Thompson and Christian Northe},
  journal={Journal of High Energy Physics},
  year={2020},
  volume={2020},
  pages={1-62}
}

• J. Erdmenger, C. Melby-Thompson, Christian Northe
• Published 14 January 2020
• Physics
• Journal of High Energy Physics

Boundary, defect, and interface RG flows, as exemplified by the famous Kondo model, play a significant role in the theory of quantum fields. We study in detail the holographic dual of a non-conformal supersymmetric impurity in the D1/D5 CFT. Its RG flow bears similarities to the Kondo model, although unlike the Kondo model the CFT is strongly coupled in the holographic regime. The interface we study preserves d = 1 N $$ \mathcal{N} $$ = 4 supersymmetry and flows to conformal fixed points in both the UV and IR. The interface’s UV fixed point is described by d = 1 fermionic degrees of freedom, coupled to a gauge connection on the CFT target space that is induced by the ADHM construction. We briefly discuss its field-theoretic properties before shifting our focus to its holographic dual. We analyze the supergravity dual of this interface RG flow, first in the probe limit and then including gravitational backreaction. In the probe limit, the flow is realized by the puffing up of probe branes on an internal S 3 via the Myers effect. We further identify the backreacted supergravity configurations dual to the interface fixed points. These supergravity solutions provide a geometric realization of critical screening of the defect degrees of freedom. This critical screening arises in a way similar to the original Kondo model. We compute the g -factor both in the probe brane approximation and using backreacted supergravity solutions, and show that it decreases from the UV to the IR as required by the g -theorem.