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.

Unitary Time Evolution and Vacuum for a Quantum Stable Ghost

This paper demonstrates that a quantum system comprising a harmonic oscillator polynomially coupled to a ghost with negative kinetic energy can be consistently quantized with a well-defined vacuum and manifestly unitary evolution, provided the system possesses an integral of motion with a positive discrete spectrum that ensures stability despite the Hamiltonian's unbounded spectrum.

Cédric Deffayet, Atabak Fathe Jalali, Aaron Held, Shinji Mukohyama, Alexander Vikman2026-04-24⚛️ hep-th

Orbital angular momentum radiation and polarization of relativistic electrons in magnetic fields

This paper demonstrates that synchrotron radiation in uniform magnetic fields can polarize the orbital angular momentum (OAM) of relativistic vortex electrons, a process that occurs orders of magnitude faster than spin polarization and offers a new mechanism for controlling high-energy electron beams.

Ziqiang Huang, Qi Meng, Xuan Liu, Wei Ma, Zhen Yang, Liang Lu, Alexander J. Silenko, Pengming Zhang, Liping Zou2026-04-24⚛️ hep-th

Ti and Spi, Carrollian extended boundaries at timelike and spatial infinity

This paper defines invariant, Carrollian-geometric extended boundaries at timelike and spatial infinity (Ti and Spi) for asymptotically flat spacetimes, demonstrating their utility in characterizing asymptotic symmetries, realizing massive field scattering data, and naturally recovering the BMS and Poincaré groups along with Strominger's matching conditions.

Jack Borthwick, Maël Chantreau, Yannick Herfray2026-04-23⚛️ gr-qc

Derivative coupling in horizon brightened acceleration radiation: a quantum optics approach

This paper investigates Horizon Brightened Acceleration Radiation (HBAR) using derivative coupling between atoms and field momentum to resolve infrared divergences, revealing that point-like detectors exhibit frequency-independent transition probabilities due to local gravitational effects and that finite-size detectors may induce non-equilibrium thermodynamic states.

Ashmita Das, Anjana Krishnan, Soham Sen, Sunandan Gangopadhyay2026-04-23⚛️ gr-qc