⚛️ Category

gr-qc

3875 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

Effective density matrix for vacua in asymptotically flat gravity

This paper explicitly constructs the effective density matrix and modular Hamiltonian for the vacuum state of a large spherically symmetric causal diamond in four-dimensional asymptotically flat gravity by utilizing the soft effective action to integrate out soft graviton modes, thereby revealing that the variance of the modular Hamiltonian scales with the diamond's area and the inverse square of the UV cutoff.

Temple He, Prahar Mitra, Kathryn M. Zurek2026-05-26
⚛️ general relativity

Twisting asymptotically-flat spacetimes

This paper extends the Bondi formalism to asymptotically-flat spacetimes with non-vanishing twist by solving the Einstein equations for a generalized gauge, thereby deriving the complete solution space, flux-balance laws, and enhanced asymptotic symmetries (including Carroll boosts), while enabling finite radial expansions for algebraically special solutions like Kerr-Taub-NUT and supertranslated Schwarzschild.

Marc Geiller, Pujian Mao, Antoine Vincenti2026-05-26
⚛️ high-energy theory

On decoding the string from interfaces in 2d conformal field theories

This paper establishes a duality between gravitational junctions in 3D anti-de Sitter spacetime and stringy wave-packets in conformal field theories, demonstrating that these modes undergo perfect reflection without distortion and can be decoded via the entanglement entropy of intervals straddling the interface, even in the tensionless limit.

Avik Banerjee, Tanay Kibe, Ayan Mukhopadhyay, Giuseppe Policastro2026-05-26
⚛️ nuclear theory

Relativistic Dispersion Spectra across Lorentz boosted frames: Spurious modes and the enigma of causality

This paper introduces a general framework for deriving linearized dispersion spectra in Lorentz boosted frames using only local rest-frame data, revealing the emergence of causality-violating "spurious modes" and establishing a direct link between mode conservation and the causality of relativistic fluid theories.

Sayantani Bhattacharyya, Sukanya Mitra, Shuvayu Roy, Rajeev Singh2026-05-26
⚛️ general relativity

Joint constraints on Rh=ctR_h=ct cosmology from DESI DR2 BAO, CC, and SN\textit{Ia} Pantheon+^+ sample

This study compares the standard Λ\LambdaCDM model with the alternative Rh=ctR_h=ct cosmology using joint constraints from DESI DR2 BAO, cosmic chronometers, and Pantheon+^+ supernova data, finding that while both models fit the data, Λ\LambdaCDM provides a superior statistical fit and naturally explains the observed transition from deceleration to acceleration, whereas Rh=ctR_h=ct predicts a strictly linear expansion.

Amritansh Mehrotra, S. K. J. Pacif, A. F. Santos2026-05-26
⚛️ general relativity

Gravitational effects on a dissipative two-level atom in the weak-field regime

Using the Feynman-Vernon influence functional formalism, this paper derives a quantum master equation to demonstrate that a weak gravitational field modifies the spontaneous emission rate of a dissipative two-level atom interacting with a scalar field, with the enhancement or suppression of this rate depending on the atom's dipole, position, and radiation frequency due to time dilation and dipole radiation effects.

Kaito Kashiwagi, Akira Matsumura2026-05-26
🔭 astrophysics

Hamilton-Jacobi Approach to Inflationary Scenarios through Extended Entropies: An Observational Perspective

This paper employs the Hamilton-Jacobi formalism to generalize slow-roll inflation through non-standard entropy frameworks, introducing a novel Hubble parametrization that yields observationally consistent constraints on Tsallis, Rényi, and Kaniadakis parameters while analyzing the impact of tensor-to-scalar ratio uncertainties on model viability.

H R M Zarandi, Esmaiel Ebrahimi, Yo Toda2026-05-26