Super-gravity unification with bilinear R-parity violation
  Bilinear R-parity violation (BRpV) provides the simplest and most meaningful way to include such effects into the Minimal Supersymmetrical Standard Model (MSSM). It is defined by a quadratic superpotential term $\epsilon L H$ which mixes lepton and Higgs superfields and mimics the effects of models with spontaneous breaking. I review some of its main features and show how large $\epsilon$ values can lead to a small neutrino mass radiatively, without any fine-tuning. I discuss the effect of BRpV on gauge and Yukawa unification, showing how bottom--tau unification can be achieved at any value of $\tan\beta$. However, for very large m $\epsilon$ values the large $\tan\beta$ solution is ruled out. 
J. W. F. Valle