Ongoing ALPS projects
Efficient graph handling
Graphs as a basic concept are underlying a number of ALPS libraries, such as the lattice and model libraries. Today all graphs in ALPS are based on the boost graph library. While incredibly versatile, this library misses efficient implementations of some essential graph algorithms, such as identifying graph isomorphisms and graph embeddings. Both concepts are strongly needed in ALPS, e.g. to further improve "symmetry-improved" exact diagonalization codes, to enable basic routines for strong-coupling expansions, and to extend the ALPS model library to include multi-site interaction terms. Together with Simon Trebst efficient C++ implementations of these codes are currently implemented, and we should have these libraries available in spring of 2007.