Surface defect, anomalies and b-extremization
Abstract Quantum field theories (QFT) in the presence of defects exhibit new types of anomalies which play an important role in constraining the defect dynamics and defect renormalization group (RG) flows. Here we study surface defects and their anomalies in conformal field theories (CFT) of general...
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| Format: | Article |
| Language: | English |
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SpringerOpen
2021-11-01
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| Series: | Journal of High Energy Physics |
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| Online Access: | https://doi.org/10.1007/JHEP11(2021)122 |
| _version_ | 1818932718376845312 |
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| author | Yifan Wang |
| author_facet | Yifan Wang |
| author_sort | Yifan Wang |
| collection | DOAJ |
| description | Abstract Quantum field theories (QFT) in the presence of defects exhibit new types of anomalies which play an important role in constraining the defect dynamics and defect renormalization group (RG) flows. Here we study surface defects and their anomalies in conformal field theories (CFT) of general spacetime dimensions. When the defect is conformal, it is characterized by a conformal b-anomaly analogous to the c-anomaly of 2d CFTs. The b-theorem states that b must monotonically decrease under defect RG flows and was proven by coupling to a spurious defect dilaton. We revisit the proof by deriving explicitly the dilaton effective action for defect RG flow in the free scalar theory. For conformal surface defects preserving N $$ \mathcal{N} $$ = (0, 2) supersymmetry, we prove a universal relation between the b-anomaly and the ’t Hooft anomaly for the U(1) r symmetry. We also establish the b-extremization principle that identifies the superconformal U(1) r symmetry from N $$ \mathcal{N} $$ = (0, 2) preserving RG flows. Together they provide a powerful tool to extract the b-anomaly of strongly coupled surface defects. To illustrate our method, we determine the b-anomalies for a number of surface defects in 3d, 4d and 6d SCFTs. We also comment on manifestations of these defect conformal and ’t Hooft anomalies in defect correlation functions. |
| first_indexed | 2024-12-20T04:36:56Z |
| format | Article |
| id | doaj.art-c067884afd894dc698f60e7eed9e12cb |
| institution | Directory Open Access Journal |
| issn | 1029-8479 |
| language | English |
| last_indexed | 2024-12-20T04:36:56Z |
| publishDate | 2021-11-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Journal of High Energy Physics |
| spelling | doaj.art-c067884afd894dc698f60e7eed9e12cb2022-12-21T19:53:14ZengSpringerOpenJournal of High Energy Physics1029-84792021-11-0120211113310.1007/JHEP11(2021)122Surface defect, anomalies and b-extremizationYifan Wang0Center of Mathematical Sciences and Applications, Harvard UniversityAbstract Quantum field theories (QFT) in the presence of defects exhibit new types of anomalies which play an important role in constraining the defect dynamics and defect renormalization group (RG) flows. Here we study surface defects and their anomalies in conformal field theories (CFT) of general spacetime dimensions. When the defect is conformal, it is characterized by a conformal b-anomaly analogous to the c-anomaly of 2d CFTs. The b-theorem states that b must monotonically decrease under defect RG flows and was proven by coupling to a spurious defect dilaton. We revisit the proof by deriving explicitly the dilaton effective action for defect RG flow in the free scalar theory. For conformal surface defects preserving N $$ \mathcal{N} $$ = (0, 2) supersymmetry, we prove a universal relation between the b-anomaly and the ’t Hooft anomaly for the U(1) r symmetry. We also establish the b-extremization principle that identifies the superconformal U(1) r symmetry from N $$ \mathcal{N} $$ = (0, 2) preserving RG flows. Together they provide a powerful tool to extract the b-anomaly of strongly coupled surface defects. To illustrate our method, we determine the b-anomalies for a number of surface defects in 3d, 4d and 6d SCFTs. We also comment on manifestations of these defect conformal and ’t Hooft anomalies in defect correlation functions.https://doi.org/10.1007/JHEP11(2021)122Anomalies in Field and String TheoriesBoundary Quantum Field TheoryConformal Field TheorySupersymmetric Gauge Theory |
| spellingShingle | Yifan Wang Surface defect, anomalies and b-extremization Journal of High Energy Physics Anomalies in Field and String Theories Boundary Quantum Field Theory Conformal Field Theory Supersymmetric Gauge Theory |
| title | Surface defect, anomalies and b-extremization |
| title_full | Surface defect, anomalies and b-extremization |
| title_fullStr | Surface defect, anomalies and b-extremization |
| title_full_unstemmed | Surface defect, anomalies and b-extremization |
| title_short | Surface defect, anomalies and b-extremization |
| title_sort | surface defect anomalies and b extremization |
| topic | Anomalies in Field and String Theories Boundary Quantum Field Theory Conformal Field Theory Supersymmetric Gauge Theory |
| url | https://doi.org/10.1007/JHEP11(2021)122 |
| work_keys_str_mv | AT yifanwang surfacedefectanomaliesandbextremization |