gr-qc papers | Gist.Science

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.

⚛️ lattice

Symmetry-based theory of Dirac fermions on two-dimensional hyperbolic crystals: Coupling to the spin connection

This paper establishes a symmetry-based framework for Dirac fermions on two-dimensional hyperbolic lattices by incorporating spin-curvature coupling via a discrete spin connection, demonstrating through both continuum theory and numerical simulations that this interaction leads to a robust, nonvanishing low-energy density of states which enhances susceptibility to interaction-driven instabilities.

Ana Djordjević, Marija Dimitrijević Ćirić, Vladimir Juričić2026-07-29

⚛️ general relativity

Characteristic Decomposition for Relativistic Numerical Simulations: I. Hydrodynamics

This paper introduces a novel method based on quasi-invertible transformations from the comoving frame to derive a simplified characteristic decomposition for relativistic hydrodynamics, including a new result for fluids in nuclear statistical equilibrium, thereby laying the groundwork for applying full-wave Riemann solvers in future GRMHD simulations.

Saul A. Teukolsky2026-07-29

⚛️ general relativity

Characteristic Decomposition for Relativistic Numerical Simulations: II. Magnetohydrodynamics

This paper derives the characteristic decomposition for General Relativistic Magnetohydrodynamics (GRMHD) in the simulation's coordinate frame using conserved variables by applying quasi-invertible transformations, thereby enabling the use of highly accurate full-wave Riemann solvers with a simpler formulation than previously attempted.

Saul A. Teukolsky2026-07-29

⚛️ nuclear experiments

An Effective Upper Bound on the Pressure-to-Energy Density Ratio in Neutron Stars

This paper refines the theoretical upper bound on the central pressure-to-energy density ratio in neutron stars to approximately 0.385 by combining causality constraints with mass-sphere stability conditions within the IPAD-TOV framework, establishing a robust, EOS-insensitive probe for the microphysics of cold superdense matter.

Bao-Jun Cai, Bao-An Li, Yu-Gang Ma2026-07-29

⚛️ quantum physics

Can a quantum circuit detect the Unruh effect?

This paper proposes and analyzes a practical implementation using superconducting fluxonium circuits to detect the timelike Unruh effect by modulating an excited-state transition frequency to accumulate a geometric phase, achieving a three-order-of-magnitude sensitivity enhancement over traditional detectors.

Pravin Kumar Dahal, Timothy C. Ralph, William J. Munro, Arkady Fedorov, James Q. Quach2026-07-29

⚛️ quantum physics

Topology-dependent relativistic degradation of multipartite entanglement

This paper demonstrates that the degradation of multipartite entanglement under relativistic acceleration depends critically on the network's topology, revealing that accelerating a peripheral qubit in a three-qubit Star state induces unique entanglement revivals and robustness patterns distinct from those observed when the central qubit accelerates.

Shu-Min Wu, Si-Han Shang, Xu Han, Hui-Chen Yang, Qianqian Liu2026-07-29

⚛️ high-energy theory

OPE = QNM

This paper establishes a fundamental connection between the thermal operator product expansion (OPE) and quasinormal modes (QNM) in large- $N$ CFTs by demonstrating their overlapping convergence in the complex time plane, thereby deriving new analytic results for QNM asymptotics, numerical methods to extract low-overtone QNMs from OPE data, and sum rules that enable a new thermal bootstrap program where these two descriptions mutually constrain each other.

Paolo Arnaudo, Cristoforo Iossa, Robin Karlsson, Benjamin Withers2026-07-29

⚛️ phenomenology

Gravitational waves decay in vacuum: a low energy effect of quantized gravitation

This paper proposes that classical gravitational waves, when treated as coherent states of quantized gravitons, can decay into photon pairs or light particles—a quantum process forbidden classically but enhanced by graviton number—thereby offering a novel detection method and enabling new cosmological constraints through the resulting photon injection.

Diego Blas, José Antonio Oller2026-07-29

⚛️ general relativity

Tidal deformation of an accreting compact object

This paper demonstrates that while a self-gravitating accretion disk significantly amplifies the tidal response of Schwarzschild-like exotic compact objects, the characteristic logarithmic dependence on compactness remains intact, preserving the potential to distinguish horizonless objects from black holes in gravitational-wave observations.

Avijit Chowdhury, Chiranjeeb Singha, Kazuharu Bamba, Sumanta Chakraborty2026-07-29

🔭 astrophysics

Primordial Physics in the Nonlinear Universe: Revealing the oscillating halo bias from cosmological collider models

This paper introduces a new simulation method to accurately model cosmological collider signatures, presenting the first measurements of oscillating halo bias in simulations and demonstrating that its mass-dependent amplitude and phase provide a robust, unique probe of primordial high-energy physics that is distinct from observational systematics.

Dhayaa Anbajagane, Neal Dalal2026-07-29