Ultra-high energy particle collisions in a regular spacetime without blackholes or naked singularities

Ultra-High Energy Quenching of the LPM Effect: Implications for GZK-Violating Events

Ultra-high excitation features in hot white dwarfs: A DAO and three DO stars discovered by the Hamburg-Schmidt survey.

Ultra-high observations of the prominence-corona transition region

Ultra-High Precision CCD Photometry

Ultra-high precision cosmology from gravitational waves

Ultra-High-Density Molecular Core and Warped Nuclear Disk in the Deep Potential of Radio-Lobe Galaxy NGC 3079

Ultra-High-Energy Cosmic Ray Acceleration by Magnetic Reconnection in Newborn Accretion Induced Collapse Pulsars

Ultra-High-Energy Cosmic Ray Acceleration by Magnetic Reconnection in Newborn Pulsars

Ultra-high-energy cosmic ray acceleration by relativistic blast waves

Ultra-High-Energy Cosmic Ray Contribution from the Spin-Down Power of Black Holes

Ultra-High-Energy Cosmic Rays from a Magnetized Strange Star Central Engine for Gamma-Ray Bursts

Ultra-high-energy cosmic rays from relic topological defects

Ultra-High-Energy Cosmic Rays from the Radio Lobes of AGNs

Ultra-high-energy cosmic rays in a galactic wind and its termination shock

Ultra-high-precision velocity measurements of oscillations in alpha Cen A

Ultra-high-time Resolution Observations of Radio Bursts on AD Leonis

Ultra-hot plasmas and electron-positron pairs in astrophysics. Proceedings.

Ultra-light Axions: Degeneracies with Massive Neutrinos and Forecasts for Future Cosmological Observations

Ultra-Lithium-Deficient Halo Stars and Blue Stragglers: A Common Origin?