Axial gravity, massless fermions and trace anomalies

Bonora, Loriano and Cvitan, Maro and Prester, P. Dominis and Duarte Pereira, Antonio and Giaccari, Stefano and Štemberga, Tamara (2017) Axial gravity, massless fermions and trace anomalies. European Physical Journal C, 77 (8). pp. 511-32. ISSN 1434-6044

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Abstract

This article deals with two main topics. One is odd parity trace anomalies in Weyl fermion theories in a 4d curved background, the second is the introduction of axial gravity. The motivation for reconsidering the former is to clarify the theoretical background underlying the approach and complete the calculation of the anomaly. The reference is in particular to the difference between Weyl and massless Majorana fermions and to the possible contributions from tadpole and seagull terms in the Feynman diagram approach. A first, basic, result of this paper is that a more thorough treatment, taking account of such additional terms and using dimensional regularization, confirms the earlier result. The introduction of an axial symmetric tensor besides the usual gravitational metric is instrumental to a different derivation of the same result using Dirac fermions, which are coupled not only to the usual metric but also to the additional axial tensor. The action of Majorana and Weyl fermions can be obtained in two different limits of such a general configuration. The results obtained in this way confirm the previously obtained ones.

Item Type: Article
Keywords: trace anomaly, Pontryagin density, massless fermions
Date: August 2017
Subjects: NATURAL SCIENCES > Physics
Additional Information: © The Author(s) 2017. This article is an open access publication. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Funded by SCOAP3. Received: 4 April 2017. Accepted: 13 July 2017. Published online: 01 August 2017.
Divisions: Faculty of Science > Department of Physics
Project code: UIP-2013-11-8946
Publisher: Springer
Depositing User: Gordana Stubičan Ladešić
Date Deposited: 08 Sep 2017 15:54
Last Modified: 08 Sep 2017 15:54
URI: http://digre.pmf.unizg.hr/id/eprint/5556

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