N=2cascade revisited and the enhançon bearings

Abstract

Supergravity backgrounds with varying fluxes generated by fractional branes at nonisolated Calabi-Yau singularities had escaped a precise dual field theory interpretation so far. In the present work, considering the prototypical example of such models, the $\mathbb{C}\ifmmode\times\else\texttimes\fi{}{\mathbb{C}}^{2}/{\mathbb{Z}}_{2}$ orbifold, we propose a solution for this problem, and show that the known cascading solution corresponds to a vacuum on the Coulomb branch of the corresponding quiver gauge theory involving a sequence of strong coupling transitions reminiscent of the baryonic root of $\mathcal{N}=2$ supersymmetric quantum chromodynamics . We also find a slight modification of this cascading vacuum which upon mass deformation is expected to flow to the Klebanov-Strassler cascade. Finally, we discuss an infinite class of vacua on the Coulomb branch whose renormalization group flows include infinitely coupled conformal regimes, and explain their gravitational manifestation in terms of new geometric structures that we dub enhan\ifmmode \mbox{\c{c}}\else \c{c}\fi{}on bearings. Repulson-free backgrounds dual to all the vacua we analyze are explicitly provided.