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A<sc>bstract</sc> We study a surface defect in the free and criticalO(N) vector models, defined by adding a quadratic perturbation localized on a two-dimensional subspace of thed-dimensional CFT. We compute the beta function for the corresponding defect renormalization group (RG) flow, and provide evidence that at long distances the system flows to a nontrivial defect conformal field theory (DCFT). We use epsilon and largeNexpansions to compute several physical quantities in the DCFT, finding agreement across different expansion methods. We also compute the defect free energy, and check consistency with the so-calledb-theorem for RG flows on surface defects.
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This content will become publicly available on June 1, 2026
Surprises in the ordinary: O(N) invariant surface defect in the ϵ-expansion
A<sc>bstract</sc> We study anO(N) invariant surface defect in the Wilson-Fisher conformal field theory (CFT) ind= 4 –ϵdimensions. This defect is defined by mass deformation on a two-dimensional surface that generates localized disorder and is conjectured to factorize into a pair of ordinary boundary conditions ind= 3. We determine defect CFT data associated with the lightestO(N) singlet and vector operators up to the third order in theϵ-expansion, find agreements with results from numerical methods and provide support for the factorization proposal ind= 3. Along the way, we observe surprising non-renormalization properties for surface anomalous dimensions and operator-product-expansion coefficients in theϵ-expansion. We also analyze the full conformal anomalies for the surface defect.
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- PAR ID:
- 10632423
- Publisher / Repository:
- Springer Nature
- Date Published:
- Journal Name:
- Journal of High Energy Physics
- Volume:
- 2025
- Issue:
- 6
- ISSN:
- 1029-8479
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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