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.

⚛️ general relativity

Different effects of the Lorentz and Gaussian bump functions on the formation of primordial black holes and secondary gravitational waves

This paper demonstrates that, when applied to the Starobinsky inflation potential with identical parameters, Lorentzian bump functions are more effective than Gaussian ones at amplifying the curvature power spectrum, thereby generating a greater abundance of primordial black holes and stronger secondary gravitational waves.

Wei Yang, Yu-Xuan Kang, Arshad Ali, Tao-Tao Sui, Chen-Hao Wu, Ya-Peng Hu2026-01-23
⚛️ general relativity

The effect of matter discreteness on gravitational wave propagation in post-geometrical optics

This paper investigates the impact of matter discreteness on gravitational wave propagation using a post-geometrical optics approximation, concluding that while curvature effects from localized particles significantly alter angular diameter distance, the validity of the approximation is limited because large curvature spikes lead to caustic formation that invalidates the method.

Sena Atli, Syksy Rasanen2026-01-23
⚛️ general relativity

Fully-relativistic evolution of vacuum tensor inhomogeneities during inflation

This paper presents a fully-relativistic numerical method for initializing and evolving vacuum tensor inhomogeneities during inflation, establishing a correspondence between Cosmological Perturbation Theory and numerical relativity to validate constraint preservation and enable the study of nonlinear gravitational effects on primordial tensor non-Gaussianity.

Ericka Florio, E. Paul S. Shellard2026-01-22
🔭 astrophysics

Angular bispectrum of matter number counts in cosmic structures

This paper presents the first full-sky, second-order perturbation theory computation of the angular bispectrum for matter number counts without the Limber approximation, incorporating both Newtonian and relativistic effects, and validates these theoretical predictions against relativistic light-cone simulations while providing publicly available code.

Thomas Montandon, Enea Di Dio, Cornelius Rampf, Julian Adamek2026-01-22