Dirac Fields in Loop Quantum Gravity and Big Bang Nucleosynthesis
arXiv:0710.5734 · doi:10.1103/PhysRevD.77.084003
Abstract
Big Bang nucleosynthesis requires a fine balance between equations of state for photons and relativistic fermions. Several corrections to equation of state parameters arise from classical and quantum physics, which are derived here from a canonical perspective. In particular, loop quantum gravity allows one to compute quantum gravity corrections for Maxwell and Dirac fields. Although the classical actions are very different, quantum corrections to the equation of state are remarkably similar. To lowest order, these corrections take the form of an overall expansion-dependent multiplicative factor in the total density. We use these results, along with the predictions of Big Bang nucleosynthesis, to place bounds on these corrections.
15 pages, 2 figures; v2: new discussion of relevance of quantum gravity corrections (Sec. II) and new estimates (Sec. V)
References in corpus (36)
- Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
- Background Independent Quantum Gravity: A Status Report
- Quantum Nature of the Big Bang: Improved dynamics
- Real Ashtekar Variables for Lorentzian Signature Space-times
- Quantum Spin Dynamics (QSD)
- Barbero's Hamiltonian derived from a generalized Hilbert-Palatini action
- Loop Quantum Cosmology
- Primordial Nucleosynthesis: Theory and Observations
- QSD V : Quantum Gravity as the Natural Regulator of Matter Quantum Field Theories
- The cosmological baryon density from the deuterium to hydrogen ratio towards QSO absorption systems: D/H towards Q1243+3047
- Real and complex connections for canonical gravity
- A Realistic Determination of the Error on the Primordial Helium Abundance: Steps Toward Non-Parametric Nebular Helium Abundances
- Quantum Gravity, Torsion, Parity Violation and all that
- Physical effects of the Immirzi parameter
- A New Nucleosynthesis Constraint on the Variation of G
- Effective Equations of Motion for Quantum Systems
- Kinematical Hilbert Spaces for Fermionic and Higgs Quantum Field Theories
- Spherically Symmetric Quantum Geometry: States and Basic Operators
- Quantization Ambiguities in Isotropic Quantum Geometry
- Loop quantum gravity corrections to gravitational wave dispersion
- Loop Quantum Cosmology I: Kinematics
- Fermions in Ashtekar-Barbero Connections Formalism for Arbitrary Values of the Immirzi Parameter
- The response of primordial abundances to a general modification of and/or of the early universe expansion rate
- Loop quantum cosmology and inhomogeneities
- Lattice refining loop quantum cosmology, anisotropic models and stability
- Quantum Gravity and Higher Curvature Actions
- Loop Quantum Cosmology: Recent Progress
- Constraints on the Variation of G from Primordial Nucleosynthesis
- Canonical Gravity with Fermions
- Lattice Refining Loop Quantum Cosmology and Inflation
- Effective constraints of loop quantum gravity
- The Dark Side of a Patchwork Universe
- Lattice Refining LQC and the Matter Hamiltonian
- Do Fermions and Bosons Produce the Same Gravitational Field?
- The radiation equation of state and loop quantum gravity corrections
- Quantum gravity and cosmological observations
Cited by in corpus (10)
- Loop Quantum Cosmology: A Status Report
- Primordial Nucleosynthesis: from precision cosmology to fundamental physics
- Anomaly freedom in perturbative loop quantum gravity
- Einstein-Cartan wormhole solutions
- Consistent Loop Quantum Cosmology
- Canonical Gravity with Fermions
- Observational hints on the Big Bounce
- Two-body Dirac equation in DSR: results for fermion-antifermion pairs
- Quantum gravity in the very early universe
- Regularization of the cosmological sector of loop quantum gravity with bosonic matter and the related problems with general covariance of quantum corrections