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Conformal boundary conditions for a 4d scalar field

by Lorenzo Di Pietro, Edoardo Lauria, Pierluigi Niro

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Submission summary

Authors (as registered SciPost users): Edoardo Lauria
Submission information
Preprint Link: https://arxiv.org/abs/2312.11633v2  (pdf)
Date accepted: 2024-03-12
Date submitted: 2024-03-06 09:49
Submitted by: Lauria, Edoardo
Submitted to: SciPost Physics
Ontological classification
Academic field: Physics
Specialties:
  • High-Energy Physics - Theory
Approach: Theoretical

Abstract

We construct unitary, stable, and interacting conformal boundary conditions for a free massless scalar in four dimensions by coupling it to edge modes living on a boundary. The boundary theories we consider are bosonic and fermionic QED$_3$ with $N_f$ flavors and a Chern-Simons term at level $k$, in the large-$N_f$ limit with fixed $k/N_f$. We find that interacting boundary conditions only exist when $k\neq 0$. To obtain this result we compute the $\beta$ functions of the classically marginal couplings at the first non-vanishing order in the large-$N_f$ expansion, and to all orders in $k/N_f$ and in the couplings. To check vacuum stability we also compute the large-$N_f$ effective potential. We compare our results with the the known conformal bootstrap bounds.

Published as SciPost Phys. 16, 090 (2024)

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