4 papers
Exact admissibility radii for the lattice topological charge of quantum spin textures
Raúl Sánchez Galán, Robert Wieser
How much can a magnetic field change before a quantum spin texture loses its skyrmion charge? For a triangulated spin- texture on quantum sites, we determine the smallest ch…
Quantum-classical crossover in finite spin-1/2 rings with Dzyaloshinsky-Moriya interaction
Raúl Sánchez Galán, Robert Wieser
We study finite spin- rings with nearest-neighbor Heisenberg exchange, Dzyaloshinsky--Moriya interaction, and an external magnetic field. We introduce an interpolation pa…
Secretary Problem Thresholds and Convergents of
Raúl Sánchez Galán
We prove that if is a continued fraction convergent of with , then, for the secretary problem with applicants, the optimal number of initially rejected app…
Vortex Harmonic Spinors on the Nappi-Witten Space
Calum Ross, Raúl Sánchez Galán
We establish a correspondence between vortex equations on flat Riemann surfaces and harmonic spinors on the Nappi--Witten space, the group manifold of a central extension of the Eu…