3 papers
astro-ph2004
Group actions, geodesic loops, and symmetries of compact hyperbolic 3-manifolds
Peter Kramer
Compact hyperbolic 3-manifolds are used in cosmological models. Their topology is characterized by their homotopy group whose elements multiply by path concatenation. The…
hep-lat2004
Induced representations of Poincare group on the lattice: spin 1/2 and 1 case
M. Lorente, P. Kramer
Following standard methods we explore the construction of the discrete Poincare group, the semidirect product of discrete translations and integral Lorentz transformations, using t…
math-ph1999
Exact electron states in 1D (quasi-) periodic arrays of delta-potentials
Peter Kramer, Tobias Kramer
Exact one-electron eigenstates in finite parts of 1D periodic and Fibonacci chains of attractive and repulsive delta potentials are computed and analyzed. Bloch and bound state bou…