Defects in conformal field theory

By M. Billò, V. Gonçalves, Edoardo Lauria, M. Meineri. 2016

333 citations recorded by the source corpus.

A bstractWe discuss consequences of the breaking of conformal symmetry by a flat or spherical extended operator. We adapt the embedding formalism to the study of correlation functions of symmetric traceless tensors in the presence of the defect. Two-point functions of a bulk and a defect primary are fixed by conformal invariance up to a set of OPE coefficients, and we identify the allowed tensor structures. A correlator of two bulk primaries depends on two cross-ratios, and we study its conformal block decomposition in the case of external scalars. The Casimir equation in the defect channel reduces to a hypergeometric equation, while the bulk channel blocks are recursively determined in the light-cone limit. In the special case of a defect of codimension two, we map the Casimir equation in the bulk channel to the one of a four-point function without defect. Finally, we analyze the contact terms of the stress-tensor with the extended operator, and we deduce constraints on the CFT data. In two dimensions, we relate the displacement operator, which appears among the contact terms, to the reflection coefficient of a conformal interface, and we find unitarity bounds for the latter.

Subfields: Atomic and Molecular Physics, and Optics, Geometry and Topology, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/7a8022d0b28159e69e34c4822909eae9f2cd5644

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atomic and Molecular Physics, and Optics

In Geometry and Topology

In Nuclear and High Energy Physics

Citations in the corpus

A general proof of the quantum null energy condition (2017, methodology): “See [63, 64, 67] for recent work on this bootstrap problem.”
Gapless Topological Phases and Symmetry-Enriched Quantum Criticality (2019, background): “[104] Marco Billò, Vasco Gonçalves, Edoardo Lauria, and Marco Meineri, “Defects in conformal field theory,” Journal of High Energy Physics 2016, 91 (2016), arXiv:1601.”
Half-BPS Wilson loop and AdS2/CFT1 (2017, background): “, [11–13, 31, 32] for recent related work) where one considers an AdSd brane inside AdSd+1, and there is a defect CFT living at the boundary of AdSd.”