⚛️ Category

gr-qc

3949 papers

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.

⚛️ high-energy theory

Probing Scalar-Tensor-Induced Gravitational Waves in the nHz Band: NANOGrav\texttt{NANOGrav} and SKA

This paper computes the energy density of scalar-tensor-induced gravitational waves (STGWs) generated during early matter-dominated and radiation-dominated eras, demonstrating that while these signals dilute in a purely matter-dominated universe, they remain viable and potentially dominant contributors to the nanohertz stochastic gravitational wave background observed by NANOGrav and detectable by the future Square Kilometre Array.

William Iania, Angelo Ricciardone2026-04-15
⚛️ nuclear theory

General equilibrium second-order hydrodynamic coefficients for free quantum fields

This paper presents a systematic calculation of non-dissipative, quantum-origin second-order hydrodynamic corrections to the stress-energy tensor and currents for free boson and Dirac fields in thermal vorticity, deriving their Kubo formulae via equilibrium correlators and demonstrating that the axial current receives vorticity-proportional corrections independent of anomalous terms.

M. Buzzegoli (U. Florence), E. Grossi (U. Heidelberg), F. Becattini (U. Florence)2026-04-14
⚛️ high-energy experiments

Optomechanical vector sensing of new forces at 6 micron separation

This paper reports a 100-fold improvement in sensitivity for detecting new gravity-like forces at micrometer scales using optically levitated microspheres, establishing the first multi-component vector force measurements and setting stringent new upper limits on Yukawa-type interactions in the 5–10 μm range.

Gautam Venugopalan, Clarke A. Hardy, Kenneth Kohn, Yuqi Zhu, Charles P. Blakemore, Alexander Fieguth, Jacqueline Huang (…)2026-04-14
🔬 optics

Introduction of Vacuum Fields to Cavity with Diffraction Loss

This paper establishes a rigorous quantum optical framework for analyzing diffraction-induced vacuum field injection in DECIGO's Fabry-Perot cavities, demonstrating that while such losses slightly increase radiation pressure noise, cavity detuning combined with homodyne detection and optical-spring locking can effectively mitigate these effects to enhance the detector's sensitivity to primordial gravitational waves.

Kurumi Umemura, Tomohiro Ishikawa, Kenji Tsuji, Shoki Iwaguchi, Yutaro Enomoto, Yuta Michimura, Kentaro Komori, Keiko Ko (…)2026-04-14
⚛️ general relativity

Comparative Study of Early-Universe Epochs in an f(R,Lm)f(R,L_m) Gravity Model with Effective Curvature--Matter Interaction and Λ\LambdaCDM Cosmology

This paper investigates a specific f(R,Lm)f(R, L_m) gravity model with effective curvature-matter interaction, demonstrating through statistical analysis of distance modulus data and a comparative study of early-Universe epochs that it predicts an earlier onset of structure formation and a higher matter-radiation equality redshift than standard Λ\LambdaCDM cosmology while remaining consistent with observed recombination data.

G. K. Goswami, J. P. Saini2026-04-14
⚛️ general relativity

Interacting kk-essence field with non-pressureless Dark Matter: Cosmological Dynamics and Observational Constraints

This paper investigates interacting kk-essence dark energy models with non-pressureless dark matter under two interaction scenarios, demonstrating through autonomous system analysis and extensive observational constraints that these models successfully reproduce cosmological evolution, yield H0H_0 values of 67–70 km/s/Mpc, and remain statistically competitive with the standard Λ\LambdaCDM model.

Saddam Hussain, Qiang Wu, Tao Zhu2026-04-14
⚛️ general relativity

Scattering of massive particles from black holes and naked singularities

This paper presents a numerical study demonstrating that while massive particles scattering off Reissner-Nordström black holes are confined to a narrow range of deflection angles due to an event horizon, those interacting with naked singularities are scattered in all directions by a repulsive core, leading to distinct observable signatures in tidal disruption events.

Angelos Karakonstantakis, Włodek Kluźniak, Maciek Wielgus2026-04-14