Study of the spectral properties of spin ladders in different   representations via a renormalization procedure
  We implement an algorithm which is aimed to reduce the dimensions of the Hilbert space of quantum many-body systems by means of a renormalization procedure. We test the role and importance of different representations on the reduction process by working out and analyzing the spectral properties of strongly interacting frustrated quantum spin systems. 
Tarek Khalil, Jean Richert
quant-ph cond-mat.str-el nucl-th