| Texto completo | |
| Autor(es): |
Erdmenger, Johanna
;
Matthaiakakis, Ioannis
;
Meyer, Rene
;
Vassilevich, Dmitri
Número total de Autores: 4
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Journal of High Energy Physics; v. N/A, n. 12, p. 21-pg., 2024-12-19. |
| Resumo | |
There exists a long-standing debate regarding the torsion contribution to the 4d chiral anomaly of a Dirac fermion. Central to this debate is the Nieh-Yan anomaly, which has been considered ill-defined and a regularization artifact. Using a heat-kernel approach, we examine the relationship between the Dirac operator index, the Nieh-Yan invariant and the torsional anomaly. We show the Nieh-Yan invariant vanishes on spacetimes without boundaries, if the Dirac index is well-defined. In the known examples of non-vanishing Nieh-Yan invariant on manifolds without boundaries, the heat kernel expansion breaks down, making the index ill-defined. Finally, for finite boundaries we identify several finite bulk and boundary anomaly terms, alongside bulk and boundary Nieh-Yan terms. We construct explicit counterterms that cancel the Nieh-Yan terms and argue that the boundary terms give rise to a torsional anomalous Hall effect. Our results emphasize the importance of renormalization conditions, as these can affect the non-thermal Nieh-Yan anomaly coefficients. In addition, we demonstrate that anomalous torsional transport may arise even without relying on the Nieh-Yan invariant. (AU) | |
| Processo FAPESP: | 21/10128-0 - Teoria quântica de campos sob a influência de condições externas |
| Beneficiário: | Dmitry Vasilevich |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |