Background Independent Quantum Gravity: A Status Report

gr-qc 2026-06 unverdicted novelty 7.0 of 10

Develops a matrix-free SRQ-based action for the AL volume operator that exactly preserves the kernel and supports large-scale Monte Carlo and spectral estimates without dense matrices.

gr-qc 2026-08 conditional novelty 6.0 of 10

The absorption cross section of massless scalar waves by a charged loop-quantum-gravity black hole increases with the quantum parameter in an intermediate frequency band, decreases with charge, and matches classical a...

gr-qc 2026-08 conditional novelty 6.0 of 10

In a loop quantum cosmology model with negative cosmological constant, semiclassical states built by integrating over all superselection sectors behave no differently from single-sector states, with differences below ...

gr-qc 2026-05 unverdicted novelty 6.0 of 10

Variational minimization of the squared Hamiltonian constraint in a truncated one-vertex loop gravity model yields three classes of near-kernel states; one factorized branch matches reduced Thiemann coherent states wi...

gr-qc 2025-11 conditional novelty 6.0 of 10

Emergent gravity is recast as an Otto cycle; adding work legs yields Lorentz violation and matter creation that can drive late-time cosmic acceleration.

gr-qc 2025-07 unverdicted novelty 6.0 of 10

Loop quantum cosmology models harbor physical singularities or inconsistent space-time structures, with a new effective Friedmann equation revealing a sub-Planckian bounce after a singularity at infinite scale factor ...

gr-qc 2025-07 conditional novelty 6.0 of 10

Quasinormal frequencies of nonlocal gravity black holes deviate from Schwarzschild values by up to about 12%, and the derived bounds on the model parameters α and k depend on projected detector sensitivity.

gr-qc 2025-06 conditional novelty 6.0 of 10

In a polymerized loop-quantum-gravity black hole model, a collapsing dust shell bounces and, for sufficiently heavy shells, follows a spacelike trajectory through the horizon, implying a finite horizon lifetime and a ...

gr-qc 2025-02 conditional novelty 6.0 of 10

The one-loop effective action from the LQG coherent state path integral is computed and found to be UV-finite, with the dynamical area j0 > 0 at the quantum level.

gr-qc 2025-02 conditional novelty 6.0 of 10

For a quantum-corrected spacetime, the fundamental quasinormal mode differs little from Schwarzschild, higher overtones deviate significantly, and wormhole states have extremely long-lived modes.

gr-qc 2025-01 conditional novelty 6.0 of 10

Static, spherically symmetric traversable wormholes are built in revised Deser-Woodard nonlocal gravity by reconstructing the theory's distortion function from chosen wormhole metrics.

hep-th 2024-11 conditional novelty 6.0 of 10

Exact complex power-law solutions of pure quadratic gravity, named powerballs, can match a Schwarzschild black hole just outside its horizon and give a finite-action model of the quantum interior.

gr-qc 2019-08 conditional novelty 6.0 of 10

The polymer Wigner functional for a real scalar field is derived as a weak covariance limit of the Gaussian-measure Wigner functional, reproducing earlier GNS and Fock results.

gr-qc 2026-08 conditional novelty 5.0 of 10

A charged anti-de Sitter regular black hole with a Minkowski core is derived from a covariant effective Hamiltonian, and its thermodynamics show a phase transition that disappears above a critical value of the regular...

gr-qc 2026-07 conditional novelty 5.0 of 10

In unimodular loop quantum cosmology, an α-attractor potential allows a potential-energy-dominated bounce at the Planck scale that is consistent with CMB observations and may show quantum-gravity imprints.

gr-qc 2026-06 unverdicted novelty 5.0 of 10

A covariant signature-change layer between a Euclidean cap and a Lorentzian universe acts as a geometric, inflaton-free fluid that accelerates expansion while the interpolator slope exceeds a curvature-dependent threshold.

gr-qc 2026-06 unverdicted novelty 5.0 of 10

Extends quantum Oppenheimer-Snyder collapse model to higher dimensions plus cosmological constant and reports modified AdS black-hole thermodynamics with finite small-black-hole temperature and an extra quantum-induce...

gr-qc 2026-05 unverdicted novelty 5.0 of 10

In a path-integral model of timeless quantum systems, time evolution arises when a clock is prepared in a semiclassical state, showing that the cosine problem in quantum gravity follows from time-reversal invariance a...

gr-qc 2026-02 conditional novelty 5.0 of 10

In a flat, empty unimodular quantum cosmology in connection variables, positive-cosmological-constant wave functions vanish at zero volume, while a negative cosmological constant is excluded by operator regularity and...

gr-qc 2025-10 reject novelty 5.0 of 10

In mLQC-I, Bianchi I shear is claimed to decay exponentially after the bounce, producing isotropization independent of the matter content.

gr-qc 2025-10 conditional novelty 5.0 of 10

In LQC and mLQC-I, tuned ekpyrotic-plus-inflation potentials can yield w>1 at the bounce and at least 60 e-folds of post-bounce inflation.

gr-qc 2025-09 conditional novelty 5.0 of 10

For the covariant quantum-corrected black hole without Cauchy horizons, the effective potential, circular orbits, ISCO, and bound trajectories of spinning particles depend only weakly on the quantum parameter but stro...

gr-qc 2025-06 conditional novelty 5.0 of 10

EHT shadow data constrain the EMCS black hole charge and scalar hair to about 0.1 and 0.01 levels, while LISA EMRI waveforms could reach 0.01 and 0.0001 levels.

gr-qc 2024-12 conditional novelty 5.0 of 10

In the rotating loop quantum black hole spacetime, the maximum magnetic Penrose process efficiency decreases with the quantum parameter epsilon, from 20.7% at epsilon=0 to about 19.3% at the maximal spin for epsilon=0.3.

gr-qc 2024-12 conditional novelty 5.0 of 10

The paper reformulates quantum-reduced loop gravity with a master constraint operator and finds that its single-node Hamiltonian matches the Bianchi I loop quantum cosmology Hamiltonian.

gr-qc 2024-11 conditional novelty 5.0 of 10

In a Chern-Simons gravity model, quantum-ordering-dependent imaginary parts of the gravitational anomaly condensate give inflation a finite lifetime and imply the string scale is about one tenth of the Planck mass.

gr-qc 2022-05 conditional novelty 5.0 of 10

EHT observations of Sgr A* constrain deviations from GR black hole solutions including regular BHs, string-inspired spacetimes, and BH mimickers, with some limits exceeding cosmological bounds.

hep-th 2019-09 conditional novelty 5.0 of 10

In polymer quantization, a uniformly accelerated Unruh-DeWitt detector sees a non-thermal vacuum response that can be mimicked by the Fock-space two-point function with a finite regulator ε≈2.16 instead of the usual ε...

gr-qc 2019-08 conditional novelty 5.0 of 10

A graphical consistency check between the fundamental and alternative flux operators in loop quantum gravity fixes the volume-operator constant κ_reg to 1/2.

gr-qc 2026-07 conditional novelty 4.0 of 10

Scalar perturbations of the loop quantum black bounce spacetime produce echoes in traversable-wormhole configurations with a double-barrier effective potential, but not in regular-black-hole configurations with a sing...

gr-qc 2026-07 reject novelty 4.0 of 10

For noncommutative RN-AdS black holes, the paper claims bulk and boundary thermodynamic topological charges equal to zero and derives perturbative second-law corrections to the remnant-mass bound.

gr-qc 2025-10 unverdicted novelty 4.0 of 10

The work calculates scalar quasinormal mode spectra for a rotating quantum-corrected black hole and constructs a methodological pipeline to infer the quantum correction parameter from gravitational-wave ringdown data ...

gr-qc 2025-10 conditional novelty 4.0 of 10

For the no-Cauchy-horizon quantum-corrected metric, a larger quantum parameter produces larger horizon, photon sphere, ISCO, and shadow, with narrower and tighter-spaced photon and lensed rings.

hep-ph 2025-05 reject novelty 4.0 of 10

Using the proton's quark pressure profile from a GPD fit, the authors update upper bounds on the EiBI gravity parameter kappa to about 0.1 to 0.3 in the quoted units.

hep-th 2025-01 conditional novelty 4.0 of 10

For a deformed AdS-Schwarzschild black hole, increasing the deformation parameter raises the Hawking-Page temperature, while thermal corrections mainly alter small-horizon thermodynamics and leave second-order phase t...

gr-qc 2024-11 reject novelty 4.0 of 10

In the U(1)^3 toy model of loop quantum gravity, the authors rearrange the quantum Hamiltonian constraint into a discrete evolution equation and, via a questionable continuum limit, a Schrödinger-like equation with a ...

gr-qc 2024-11 unverdicted novelty 4.0 of 10

The paper argues that an effective 'hydrodynamics on superspace' framework, realized in TGFT condensate cosmology, can unify quantum gravity and cosmology.

gr-qc 2024-11 conditional novelty 4.0 of 10

For two covariant effective quantum gravity black holes, the quantum parameter ζ shrinks the shadow at moderate spin and creates a cuspy shadow edge near extremality.

gr-qc 2026-07 conditional novelty 2.0 of 10

Assuming an extra 'absolute consistency' rule, gravitational-wave validation of the area theorem forces negative entropy corrections, which restricts F(R) gravity and would rule out two axions or an axion plus a graviton.