Toller matrices T^(±) in causal spinfoam amplitudes satisfy T^(+) + T^(-) = D and admit equivalent definitions via analyticity, iε prescription, and boost-eigenvalue integrals that reproduce the Euclidean-to-Lorentzian Wick rotation.
Real Ashtekar variables for Lorentzian signature space times
9 Pith papers cite this work. Polarity classification is still indexing.
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Pith papers citing it
abstract
I suggest in this letter a new strategy to attack the problem of the reality conditions in the Ashtekar approach to classical and quantum general relativity. By writing a modified Hamiltonian constraint in the usual $SO(3)$ Yang-Mills phase space I show that it is possible to describe space-times with Lorentzian signature without the introduction of complex variables. All the features of the Ashtekar formalism related to the geometrical nature of the new variables are retained; in particular, it is still possible, in principle, to use the loop variables approach in the passage to the quantum theory. The key issue in the new formulation is how to deal with the more complicated Hamiltonian constraint that must be used in order to avoid the introduction of complex fields.
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Collective excitations analogous to phonons are derived in quantum gravity condensates within a group field theory model, yielding leading beyond-mean-field corrections to emergent Friedmann dynamics.
γ-duality in the EPRL spinfoam model determines the relation between parity-even and parity-odd terms in an effective gravity theory, allowing the Barbero-Immirzi parameter to be measured from inflationary tensor observables.
Cross-correlations between quantum degrees of freedom are required for consistent effective dynamics in Brans-Dicke Bianchi I cosmology, smoothing bounces and keeping energy density finite.
Loop quantum gravity effective dynamics resolves classical singularities in the JNW spacetime via bounces in the μ0 scheme but produces new singularities in the Dirac-observable scheme.
Einstein-Cartan pseudoscalaron inflation coupled to type-I seesaw neutrinos makes nonthermal leptogenesis a necessary mechanism for the baryon asymmetry, yielding ns ~ 0.97, r ~ 0.004 and nB/s ~ 8.7e-11 for gamma ~ -1/100 and lightest Majorana mass ~ 10^13 GeV.
A covariant path-integral quantization of first-order Einstein-Hilbert gravity is constructed using BV formalism, yielding structural identities from Dyson-Schwinger equations and equivalence to the second-order formulation at the effective action level when the auxiliary connection is on-shell.
In N=1 supergravity as constrained BF theory, the algebra of boundary charges matches the superalgebra with translational charges vanishing on-shell from the super-torsion constraint.
This review surveys calculations and interpretations of quasinormal modes for black holes in astrophysics, higher dimensions, and holographic duals without presenting new results.
citing papers explorer
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Toller matrices and the Feynman $i\varepsilon$ in spinfoams
Toller matrices T^(±) in causal spinfoam amplitudes satisfy T^(+) + T^(-) = D and admit equivalent definitions via analyticity, iε prescription, and boost-eigenvalue integrals that reproduce the Euclidean-to-Lorentzian Wick rotation.
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Collective excitations in quantum gravity condensates
Collective excitations analogous to phonons are derived in quantum gravity condensates within a group field theory model, yielding leading beyond-mean-field corrections to emergent Friedmann dynamics.
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Spinfoams, $\gamma$-duality and parity violation in primordial gravitational waves
γ-duality in the EPRL spinfoam model determines the relation between parity-even and parity-odd terms in an effective gravity theory, allowing the Barbero-Immirzi parameter to be measured from inflationary tensor observables.
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Quantum Backreaction in Effective Brans-Dicke Bianchi I Cosmology
Cross-correlations between quantum degrees of freedom are required for consistent effective dynamics in Brans-Dicke Bianchi I cosmology, smoothing bounces and keeping energy density finite.
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Effective dynamics of Janis-Newman-Winicour spacetime
Loop quantum gravity effective dynamics resolves classical singularities in the JNW spacetime via bounces in the μ0 scheme but produces new singularities in the Dirac-observable scheme.
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Einstein-Cartan pseudoscalaron inflation, reheating and nonthermal leptogenesis
Einstein-Cartan pseudoscalaron inflation coupled to type-I seesaw neutrinos makes nonthermal leptogenesis a necessary mechanism for the baryon asymmetry, yielding ns ~ 0.97, r ~ 0.004 and nB/s ~ 8.7e-11 for gamma ~ -1/100 and lightest Majorana mass ~ 10^13 GeV.
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Covariant quantization of the Einstein-Hilbert theory in first-order form
A covariant path-integral quantization of first-order Einstein-Hilbert gravity is constructed using BV formalism, yielding structural identities from Dyson-Schwinger equations and equivalence to the second-order formulation at the effective action level when the auxiliary connection is on-shell.
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Charges of supergravity
In N=1 supergravity as constrained BF theory, the algebra of boundary charges matches the superalgebra with translational charges vanishing on-shell from the super-torsion constraint.
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Quasinormal modes of black holes: from astrophysics to string theory
This review surveys calculations and interpretations of quasinormal modes for black holes in astrophysics, higher dimensions, and holographic duals without presenting new results.