Probing Strong-Field Gravity: Black Hole Shadows, Gravitational Waves, and Relativistic Magnetic Reconnection

The relation between electromagnetic astrophysics and gravitational wave astronomy has revolutionized our understanding of extreme compact objects. High-resolution horizon-scale imaging by the Event Horizon Telescope (EHT) reveals the shadows and photon rings of supermassive black holes, while laser interferometers (LIGO-Virgo-KAGRA) detect gravitational waves from binary mergers. Meanwhile, relativistic magnetic reconnection in highly magnetized black hole magnetospheres and accretion disks serves as a primary engine driving high-energy flares, jet formation, and energy extraction mechanisms like the Comisso-Asenjo process. Connecting the structural features of black hole shadows with gravitational wave signatures and reconnection-driven plasma dynamics offers an unprecedented multi-messenger probe into spacetime geometry and magnetohydrodynamics in strong gravity regimes. This Research Topic brings together these three vital pillars of contemporary relativistic astrophysics to foster comprehensive insights into black hole physics.The main goal of this Research Topic is to unify multi-messenger observations and theoretical frameworks spanning black hole shadow imaging, gravitational wave physics, and relativistic magnetic reconnection. A major challenge in modern astrophysics is understanding how magnetohydrodynamic processes in strong-gravity environments couple with spacetime dynamics, particularly during energetic flare events, accretion state transitions, and binary compact object coalescences.To address this challenge, this topic aims to aggregate cutting-edge research across three interrelated pillars: (1) investigating how magnetic reconnection and plasmoid-driven plasma turbulence shape the variability and polarization of black hole shadows; (2) examining gravitational wave emissions (including quasinormal modes and ringdown spectra) from black holes surrounded by magnetized plasma environments or alternative gravity configurations; and (3) modeling energy release from reconnection events in black hole ergospheres alongside potential electromagnetic counterparts to gravitational wave signals. By combining general relativistic magnetohydrodynamic (GRMHD) simulations, analytical gravity models, and multi-messenger data, this topic seeks to provide a holistic understanding of energy extraction and spacetime testing around black holes.This Research Topic invites theoretical, computational, and observational manuscripts exploring the interplay between black hole shadows, gravitational waves, and magnetic reconnection. Key sub-themes include, but are not limited to:• GRMHD and particle-in-cell modeling of magnetic reconnection, plasma flares, and jet launching in black hole magnetospheres.• Shadow morphology, photon ring sub-structures, and polarimetric variability induced by relativistic reconnection events.• Gravitational wave generation, quasinormal modes, and ringdown physics in magnetized or modified-gravity environments.• Joint electromagnetic and gravitational wave signatures of compact object mergers and accretion-driven systems.• Observational implications for EHT, ngEHT, LISA, and ground-based GW detectors.We welcome Original Research, Review articles, Mini-Reviews, Perspectives, and Brief Research Reports. Topic editors: Xiao-Xiong Zeng, Muhammad Aslam, Li Guoping, Ke-Jian He, Rabia Saleem, Emmanuele Battista Source: https://www.frontiersin.org/research-topics/84336/probing-strong-field-gravity-black-hole-shadows-gravitational-waves-and-relativistic-magnetic-reconnection