Peccei-Quinn Mechanism in Gravity and the Nature of the Barbero-Immirzi Parameter

Mercuri, Simone

doi:10.1103/physrevlett.103.081302

Cited by 94 publications

(118 citation statements)

References 59 publications

Supporting

Mentioning

112

Contrasting

Order By: Relevance

“…It is important to note that, in order to preserve the standard transformation properties of the torsion tensor under the Lorentz group, the field has to be a pseudoscalar [16,28]. In other words, the geometrical content of the theory suggests the pseudoscalar nature of the BI field , which is a consequence of the peculiar interaction with the NiehYan density and is not assumed a priori.…”

Section: Effective Dynamics Of Nieh-yan Modified Gravity With Fermentioning

confidence: 99%

“…As a consequence its value can be correlated to some topological ambiguity through a dynamical Peccei-Quinn-like mechanism as, in fact, argued in [28].…”

mentioning

confidence: 94%

“…It results that, in fact, the gravitational chiral anomaly in torsional spacetimes contains a divergent term proportional to the NiehYan invariant. The necessity to reabsorb the divergence represents the motivation to promote the BI parameter to be a field [28]. This also clarifies the role played by the Nieh-Yan invariant in gravity, especially in relation with possible torsion sources as, e.g., spinor fields.…”

mentioning

confidence: 96%

“…We note that, following a common procedure, the BI parameter can be associated with the expectation value of the field [28]. As a consequence its value can be correlated to some topological ambiguity through a dynamical Peccei-Quinn-like mechanism as, in fact, argued in [28].…”

mentioning

confidence: 98%

See 3 more Smart Citations

Interaction of the Barbero-Immirzi field with matter and pseudoscalar perturbations

2009

Self Cite

View full text Add to dashboard Cite

In loop quantum gravity the classical point of departure is the Einstein-Hilbert action modified by the addition of the so-called Holst term. Classically, this term does not affect the equations of motion, but it induces a well-known quantization ambiguity in the quantum theory, parametrized by the BarberoImmirzi parameter. Recently, it has been suggested to promote the Barbero-Immirzi parameter to a field. The resulting theory, obtainable starting from the usual Holst action, is general relativity coupled to a pseudoscalar field. However, this theory turns out to have an unconventional kinetic term for the BarberoImmirzi field and a rather unnatural coupling with fermions. The main goal of this work is twofold: First, to propose a further generalization of the Holst action, which yields a theory of gravity and matter with a more natural coupling to the Barbero-Immirzi field; second, to study the possible implications for cosmology correlated to the existence of this new pseudoscalar field.

show abstract

Section: Effective Dynamics Of Nieh-yan Modified Gravity With Fermentioning

confidence: 99%

“…As a consequence its value can be correlated to some topological ambiguity through a dynamical Peccei-Quinn-like mechanism as, in fact, argued in [28].…”

mentioning

confidence: 94%

mentioning

confidence: 96%

mentioning

confidence: 98%

See 2 more Smart Citations

Interaction of the Barbero-Immirzi field with matter and pseudoscalar perturbations

2009

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, when torsion is present (for instance, when it is generated by fermions or a spacetime-dependent Barbero-Immirzi field [18][19][20][21][22]), it is natural to include it explicitly in the fundamental action, so that the Holst term is completed by a torsion-torsion piece to form the Nieh-Yan invariant [17,23]. There are several other reasons why to prefer the latter alternative.…”

Section: Ij µmentioning

confidence: 99%

Erratum: Cosmological Bardeen-Cooper-Schrieffer condensate as dark energy [Phys. Rev. D81, 043511 (2010)]

Alexander¹,

Biswas²,

Calcagni³

2010

Phys. Rev. D

View full text Add to dashboard Cite

We argue that the occurrence of late-time acceleration can conveniently be described by firstorder general relativity covariantly coupled to fermions. Dark energy arises as a Bardeen-CooperSchrieffer condensate of fermions which forms in the early universe. At late times, the gap and chemical potential evolve to have an equation of state with effective negative pressure, thus naturally leading to acceleration.

show abstract

Duality and Higher Buscher Rules in p‐Form Gauge Theory and Linearized Gravity

Chatzistavrakidis

Karagiannis

Ranjbar

2021

Fortschritte der Physik

View full text Add to dashboard Cite

We perform an in‐depth analysis of the transformation rules under duality for couplings of theories containing multiple scalars, p‐form gauge fields, linearized gravitons or (p, 1) mixed symmetry tensors. Following a similar reasoning to the derivation of the Buscher rules for string background fields under T‐duality, we show that the couplings for all classes of aforementioned multi‐field theories transform according to one of two sets of duality rules. These sets comprise the ordinary Buscher rules and their higher counterpart; this is a generic feature of multi‐field theories in spacetime dimensions where the field strength and its dual are of the same degree. Our analysis takes into account topological theta terms and generalized B‐fields, whose behavior under duality is carefully tracked. For a 1‐form or a graviton in 4D, this reduces to the inversion of the complexified coupling or generalized metric under electric/magnetic duality. Moreover, we write down an action for linearized gravity in the presence of θ‐term from which we obtain previously suggested on‐shell duality and double duality relations. This also provides an explanation for the origin of theta in the gravitational duality relations as a specific additional sector of the linearized gravity action.

show abstract

Peccei-Quinn Mechanism in Gravity and the Nature of the Barbero-Immirzi Parameter

Cited by 94 publications

References 59 publications

Interaction of the Barbero-Immirzi field with matter and pseudoscalar perturbations

Interaction of the Barbero-Immirzi field with matter and pseudoscalar perturbations

Erratum: Cosmological Bardeen-Cooper-Schrieffer condensate as dark energy [Phys. Rev. D81, 043511 (2010)]

Duality and Higher Buscher Rules in p‐Form Gauge Theory and Linearized Gravity

Contact Info

Product

Resources

About