43 citations · 152 across the 26 of their papers we have counts for
26 papers
Quasicrystals
Uwe Grimm, Peter Kramer
Mathematicians have been interested in non-periodic tilings of space for decades; however, it was the unexpected discovery of non-periodically ordered structures in intermetallic a…
A new product on 2x2 matrices
Linus Kramer, Peter Kramer, Vladimir Man'ko
We study a bilinear multiplication rule on 2x2 matrices which is intermediate between the ordinary matrix product and the Hadamard matrix product, and we relate this to the hyperbo…
Topology of Platonic Spherical Manifolds: From Homotopy to Harmonic Analysis
Peter Kramer
We carry out the harmonic analysis on four Platonic spherical three-manifolds with different topologies. Starting out from the homotopies (Everitt 2004), we convert them into deck…
Interacting electrons in a magnetic field in a center-of-mass free basis
Peter Kramer, Tobias Kramer
We present an extension of the spin-adapted configuration-interaction method for the computation of four electrons in a quasi two-dimensional quantum dot. By a group-theoretical de…
Spherical Orbifolds for Cosmic Topology
Peter Kramer
Harmonic analysis is a tool to infer cosmic topology from the measured astrophysical cosmic microwave background CMB radiation. For overall positive curvature, Platonic spherical m…
Gateways towards quasicrystals
Peter Kramer
The experimental discovery of quasicrystals by D Shechtman, D Gratias, I Blech, and J W Cahn in 1984 provided the paradigm for a new type of long-range order of solid matter in nat…