The type N Karlhede bound is sharp
The Ultrarelativistic Kerr-Geometry and its Energy-Momentum Tensor
The ultrarelativistic limit of 2D dilaton gravity and its energy momentum tensor
The ultrarelativistic Reissner-Nordstrom field in the Colombeau algebra
The Unholey Solution to Black Hole Information Loss
THE UNIQUENESS THEOREM FOR ROTATING BLACK HOLE SOLUTIONS OF SELF-GRAVITATING HARMONIC MAPPINGS
The universal 'energy' operator
The Universality of Einstein Equations
The universe as a black hole in isotropic coordinates
The Universe Dynamics from Topological Considerations
The universe dynamics in the tachyon cosmology with non-minimal coupling to matter
The universe formation by a space reduction cascade with random initial parameters
The Universe in a Soap Film
The universe out of a breathing bubble
The universe out of a monopole in the laboratory?
The Universe out of an Elementary Particle?
The universe seen at different scales
The Universe With Bulk Viscosity
The unphysical nature of "Warp Drive"
The Unruh effect and entanglement generation for accelerated atoms near a reflecting boundary