Trace anomalies in chiral theories revisited

Abstract

Motivated by the search for possible CP violating terms in the trace of the energy-momentum tensor in theories coupled to gravity we revisit the problem of trace anomalies in chiral theories. We recalculate the latter and ascertain that in the trace of the energy-momentum tensor of theories with chiral fermions at one-loop the Pontryagin density appears with an imaginary coefficient. We argue that this may break unitarity, in which case the trace anomaly has to be used as a selective criterion for theories, analogous to the chiral anomalies in gauge theories. We analyze some remarkable consequences of this fact, that seem to have been overlooked in the literature.

16 pages; v2: added 2 references in a footnote; v3: a few typos corrected, published in JHEP

References in corpus (1)

• General solutions of the Wess-Zumino consistency condition for the Weyl anomalies

Cited by in corpus (30)

• Renormalised 3-point functions of stress tensors and conserved currents in CFT
• Anomalous Transport in Holographic Boundary Conformal Field Theories
• Axial gravity, massless fermions and trace anomalies
• Weyl Anomalies of Four Dimensional Conformal Boundaries and Defects
• On the trace anomaly of a Weyl fermion
• Weyl Anomaly Induced Current in Boundary Quantum Field Theories
• Indirect searches of dark matter via polynomial spectral features
• Gravitational decoupling, hairy black holes and conformal anomalies
• On the realization of impossible anomalies
• Axial gravity and anomalies of fermions
• One-loop effective actions and higher spins
• On the trace anomaly of a Weyl fermion in a gauge background
• Trace anomaly for chiral fermions via Hadamard subtraction
• Axial gravity: a non-perturbative approach to split anomalies
• Trace Anomaly of Weyl Fermions via the Path Integral
• Can we change $c$ in four-dimensional CFTs by exactly marginal deformations?
• Trace anomaly for Weyl fermions using the Breitenlohner-Maison scheme for ${\gamma }_{\ast }$
• CP-violating super Weyl anomaly
• Weyl fermions in a non-abelian gauge background and trace anomalies
• Investigation of Pontryagin trace anomaly using Pauli-Villars regularization
• Elusive anomalies
• Conformal Contact Terms and Semi-Local Terms
• On Finiteness of 2- and 3-point Functions and the Renormalisation Group
• Correlation functions of sourced gravitational waves in inflationary scalar vector models. A symmetry based approach
• A rederivation of the conformal anomaly for spin-1/2
• Chiral current induced by torsional Weyl anomaly
• CP-violating supersymmetry anomaly
• On the simplified path integral on spheres
• Trace anomaly of Weyl fermions in the Breitenlohner--Maison scheme for ${\gamma }_{\ast }$
• The Weyl anomaly in interacting quantum field theory on curved spacetimes