Phases of unstable conifolds
  We explore the phase structure induced by closed string tachyon condensation of toric nonsupersymmetric conifold-like singularities described by an integral charge matrix $Q=(n_1 n_2 -n_3 -n_4), n_i>0, \sum_i Q_i\neq 0$, initiated in hep-th/0510104. Using gauged linear sigma model renormalization group flows and toric geometry techniques, we see a cascade-like phase structure containing decays to lower order conifold-like singularities, including in particular the supersymmetric conifold and the $Y^{pq}$ spaces. This structure is consistent with the Type II GSO projection obtained previously for these singularities. Transitions between the various phases of these geometries include flips and flops. 
K. Narayan