Quantum gravity represents the frontier where the very large meets the very small, attempting to unify Einstein's theory of gravity with the strange rules of quantum mechanics. This field explores the fundamental fabric of spacetime, seeking to understand how the universe behaves at its most extreme scales, from the heart of black holes to the moment of the Big Bang. Because these concepts often involve complex mathematics, they can feel distant to non-specialists, yet they hold the key to a complete picture of physical reality.

At Gist.Science, we bridge this gap by processing every new preprint in this category directly from arXiv. Our team provides both plain-language explanations and detailed technical summaries for each paper, ensuring that groundbreaking research is accessible to everyone, from curious students to seasoned researchers. Below are the latest papers in quantum gravity, offering fresh insights into the nature of our cosmos.

Space- vs Time-dependence in taming the infrared instability of projectable Ho\v rava Gravity

This paper investigates whether higher-derivative terms in projectable Hořava gravity can stabilize its infrared instability by evolving into static, inhomogeneous solutions, but concludes that no such static endpoints exist, thereby reinforcing the necessity of time-dependent mechanisms like cosmic expansion to conceal the instability.

Shinji Mukohyama, Jury Radkovski, Sergey Sibiryakov2026-04-13⚛️ hep-th

Relativistic single-electron wavepacket in quantum electromagnetic fields II: Quantum radiation emitted by a uniformly accelerated electron

This paper computes the quantum radiation emitted by relativistic single-electron wavepackets, demonstrating that while radiation vanishes for electrons at rest, uniformly accelerated electrons exhibit secularly growing power with a classical interpretation, and that proposed experimental signatures of the Unruh effect in specific "blind spots" are dominated by transverse deviation correlators rather than the Unruh effect itself.

Shih-Yuin Lin, Bei-Lok Hu2026-04-13⚛️ hep-th

Black Hole Dynamics at Fifth Post-Newtonian Order

This paper derives the total even-in-velocity scattering observables at fifth post-Newtonian order using a worldline action and Feynman's i0+i0^+ prescription to establish a universal conservative Hamiltonian and resolve ambiguities in Effective One Body coefficients, while demonstrating the superiority of this approach over the γ-3\gamma\text{-}3 prescription in preserving expected theoretical structures.

Rafael A. Porto, Massimiliano M. Riva2026-04-13⚛️ gr-qc

Testing the equivalence principle across the Universe: a model-independent approach with galaxy multi-tracing

This paper proposes a model-independent method using galaxy multi-tracing and relativistic corrections to test the equivalence principle on cosmological scales, forecasting that while current surveys can detect the necessary corrections, only the Square Kilometre Array (SKA) will achieve the precision required to constrain potential violations.

Sveva Castello, Ziyang Zheng, Camille Bonvin, Luca Amendola2026-04-10⚛️ gr-qc

Assessment of normalizing flows for parameter estimation on time-frequency representations of gravitational-wave data

This paper introduces GP15, a deep-learning method that combines residual networks and normalizing flows to rapidly estimate binary black hole parameters from time-frequency spectrograms, demonstrating strong agreement with LIGO-Virgo-KAGRA results while generating posterior samples in seconds.

Daniel Lanchares, Osvaldo G. Freitas, Lysiane Mornas, José A. Font, Joaquín González-Nuevo, Luigi Toffolatti, Pietro Vischia2026-04-10⚛️ gr-qc

Statistic threshold of distinguishing the environmental effects and modified theory of gravity with multiple massive black-hole binaries

This paper applies and refines a statistical dispersion metric to establish robust thresholds for distinguishing between dynamical friction from dark matter spikes and various modified gravity theories (including extra dimensions and varying GG) in future space-borne gravitational wave observations of massive black-hole binaries.

Xulong Yuan2026-04-10⚛️ gr-qc

Echoes and quasinormal modes of asymmetric black bounces

This paper investigates quasinormal modes and gravitational wave echoes in symmetric and asymmetric black bounce solutions, revealing that while symmetric horizonless configurations exhibit multiple potential barriers and distinct echoes, asymmetric models closely resemble standard Reissner-Nordström black holes without producing echoes, thereby making them difficult to distinguish observationally.

Alana C. L. Santos, Leandro A. Lessa, Roberto V. Maluf, Gonzalo J. Olmo2026-04-10⚛️ gr-qc

Greybody factors of Proca fields in Schwarzschild spacetime: A supplemental analysis based on decoupled master equations related to the Frolov-Krtouš-Kubiznák-Santos separation

This paper investigates greybody factors for Proca fields in Schwarzschild spacetime by deriving decoupled radial equations via the Frolov-Krtouš-Kubizňák-Santos transformation and employing semi-analytical methods to reveal that the even-parity vector mode exhibits enhanced transmission in a low-mass regime while the even-parity scalar mode yields systematically lower transmission than its scalar field counterpart.

Supanat Bunjusuwan, Chun-Hung Chen2026-04-10⚛️ gr-qc

Jiggled interferometer: Ground-based gravitational wave detector using rapidly-repeated free-falling test masses

The paper proposes JIGI, a novel ground-based gravitational wave detector that utilizes rapidly-repeated free-falling test masses to eliminate seismic and suspension thermal noise, achieving a sensitivity gain of approximately four orders of magnitude in the 0.1–0.3 Hz band compared to existing ground-based designs.

Shoki Iwaguchi, Bin Wu, Kurumi Umemura, Tomohiro Ishikawa, Kenji Tsuji, Ryota Nishimura, Yuta Michimura, Yutaro Enomoto, Soichiro Morisaki, Yoichi Aso, Tomotada Akutsu, Keiko Kokeyama, Seiji Kawamura2026-04-10⚛️ gr-qc