Hep-Th, or high-energy theoretical physics, explores the fundamental building blocks of our universe and the forces that govern them. Researchers in this field use complex mathematics to understand everything from subatomic particles to the behavior of black holes, often pushing the boundaries of what we know about space and time.

At Gist.Science, we monitor the arXiv repository to ensure you stay ahead of the curve in this rapidly evolving discipline. For every new preprint uploaded to arXiv under this category, our team generates both accessible plain-language overviews and detailed technical summaries, making cutting-edge research understandable regardless of your background.

Below are the latest papers in high-energy theoretical physics, curated to help you navigate the most significant recent discoveries.

Calculation of a regularized Teukolsky Green function in Schwarzschild spacetime

This paper derives exact expressions for the factors in the Hadamard form of the retarded Green function for the Teukolsky equation on Schwarzschild spacetime by utilizing a conformal direct-product metric to obtain a separable direct part and its multipolar modes, ultimately providing an improved representation of the Green function near coincidence for gravitational perturbations.

David Q. Aruquipa, Marc Casals, Brien C. Nolan2026-04-24⚛️ gr-qc

Bianchi-I Cosmology with Radiation in Asymptotically Safe Gravity

This paper investigates the late-time evolution of an anisotropic Bianchi-I universe containing radiation and electromagnetic fields within asymptotically safe gravity, revealing that quantum effects soften anisotropy in radiation-dominated scenarios while the presence of a cosmological constant ultimately drives the universe toward an isotropic de Sitter phase, whereas its absence leads to a persistent Kasner-type anisotropic regime.

Chiang-Mei Chen, Ting-Kui Fan, Rituparna Mandal, Nobuyoshi Ohta2026-04-24⚛️ gr-qc

Ghost Degrees of Freedom Without Quantum Runaway: Exact Moment Bounds from an Operator Conservation Law

This paper proves that a harmonic oscillator coupled to a ghost degree of freedom remains quantum-stable with bounded second moments for all time, provided the interaction is bounded and vanishes at large separations, thereby demonstrating that ghost-induced instabilities are not inevitable consequences of wrong-sign kinetic terms but depend critically on the interaction structure.

Christopher Ewasiuk, Stefano Profumo2026-04-24⚛️ quant-ph

Holographic complexity of conformal fields in global de Sitter spacetime

This paper computes and compares the holographic complexity of conformal quantum fields in global de Sitter spacetime using both volume and action prescriptions across two distinct setups: a CFT on the conformal boundary of AdSd+1_{d+1} and a CFT on a UV brane embedded within it, while contrasting these findings with results from alternative de Sitter coordinate patches.

Sanhita Parihar, Shubho R. Roy2026-04-24⚛️ hep-th

O(d,d)O(d,d) symmetric gravity and finite coupling holography

This paper constructs O(d,d)O(d,d) symmetric asymptotically AdS5_5 black brane solutions with infinite curvature corrections, demonstrating that while these corrections modify the approach to the singularity without resolving it, a non-trivial dilaton can dynamically generate a negative cosmological constant at small coupling to potentially explain asymptotic freedom in a string dual of QCD.

Umut Gürsoy, Pedro Vicente Marto, Edwan Préau2026-04-24⚛️ hep-th

Symplectic symmetry of quadratic-band-touching Hamiltonians in two dimensions

This paper identifies the internal low-energy symmetry of two-dimensional quadratic-band-touching Hamiltonians as the unitary symplectic group $USp(2N)$, constructs the corresponding rotationally invariant interacting theory, and demonstrates that for lattice systems like honeycomb, this symmetry reduces to the unitary group U(N)U(N) through the intersection of symplectic and orthogonal symmetries.

Igor F. Herbut, Samson C. H. Ling2026-04-24🔢 math-ph