3 papers
astro-ph.HE2025
Exotic PeVatrons as sources of ultra-high-energy gamma rays
Andrea Addazi, Salvatore Capozziello, Qingyu Gan
We explore novel classes of exotic astrophysical sources capable of producing ultra-high-energy gamma rays extending beyond the PeV scale, motivated by quantum gravity scenarios an…
gr-qc2025
Gravitational waves in minimal Maxwell gravity
Salvatore Capozziello, Qingyu Gan
We discuss the conversion mechanism from scalar field to gravitational waves in magnetic background in gravity minimal coupled to the Maxwell electrodynamics. Applying the c…
astro-ph.CO2024
Excess Radiation from Axion-Photon Conversion
Andrea Addazi, Salvatore Capozziello, Qingyu Gan +2
Two notable anomalies in radio observations -- the excess radiation in the Rayleigh-Jeans tail of the cosmic microwave background, revealed by ARCADE2, and the twice-deeper absorpt…