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

Journal Article · Sun Nov 15 04:00:00 EST 2009 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.80.104007· OSTI ID:21308624

Mercuri, Simone; Taveras, Victor ^[1]

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1. Institute for Gravitation and the Cosmos, Pennsylvania State University, Physics Department, Whitmore Lab, University Park, Pennsylvania 16802 (United States)

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 Barbero-Immirzi 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 Barbero-Immirzi 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.

• OSTI ID: 21308624
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 10 Vol. 80; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COSMOLOGY
COUPLING
DISTURBANCES
EQUATIONS OF MOTION
FERMIONS
GENERAL RELATIVITY THEORY
GRAVITATION
HILBERT SPACE
INTERACTIONS
MATTER
PERTURBATION THEORY
PSEUDOSCALARS
QUANTIZATION
QUANTUM GRAVITY
SCALAR FIELDS