RG flows and cascades of Lif₄⁽²⁾times S¹times S⁵ vacua

The (F1,D2,D8) brane configuration produces $Lif_4^{(2)}\times {S}^1\times S^5$ Lifshitz vacua supported by `massive' $B$-field. We present exact deformations of this system under which new massless $B$-modes of strings also get excited. Due to these massless modes the deformed solutions flow to conformally $Lif_4^{(3)}\times S^1\times S^5$ vacua in the IR. The latter types are supersymmetric solutions of ordinary type IIA theory. The massive and massless $B_{\mu\nu}$ modes segregate out in the IR. We confirm that the massive $B$ mode and cosmological constant indeed decouple from the theory rendering the IR field dynamics controlled by massless fields only. A similar effect is observed on the UV side of the flow where a relativistic regime reappears. We also present `cascading' Lifshitz vacua in which dynamical exponent has integral jumps along the flow, $Lif_4^{(3)}\to Lif_4^{(2)}\to Lif_4^{(1)}$. The critical $Lif_4^{(2)}$ theory separates `deconfining' $Lif_4^{(3)}$ IR theory from the confining Yang-Mills phase in UV.