69 citations · 397 across the 22 of their papers we have counts for
5 papers · 1 filter
First excitations in two- and three-dimensional random-field Ising systems
Martin Zumsande, Mikko J. Alava, Alexander K. Hartmann
We present results on the first excited states for the random-field Ising model. These are based on an exact algorithm, with which we study the excitation energies and the excitati…
Solution-space structure of (some) optimization problems
Alexander K. Hartmann, Alexander Mann, Wolfgang Radenbach
We study numerically the cluster structure of random ensembles of two NP-hard optimization problems originating in computational complexity, the vertex-cover problem and the number…
Negative-weight percolation
O. Melchert, A. K. Hartmann
We describe a percolation problem on lattices (graphs, networks), with edge weights drawn from disorder distributions that allow for weights (or distances) of either sign, i.e. inc…
RNA Secondary Structures: Complex Statics and Glassy Dynamics
S. Wolfsheimer, B. Burghardt, A. Mann +1
Models for RNA secondary structures (the topology of folded RNA) without pseudo knots are disordered systems with a complex state-space below a critical temperature. Hence, a compl…
Droplets in the two-dimensional +-J spin glass: evidence for (non-) universality
A. K. Hartmann
Using mappings to computer-science problems and by applying sophisticated algorithms, one can study numerically many problems much better compared to applying standard approaches l…