Universal RG Flows Across Dimensions and Holography

We study RG flows between superconformal field theories living in different spacetime dimensions which exhibit universal properties, independent of the details of the UV and IR theories. In particular, when the UV and IR theories are both even-dimensional we establish exact universal relations between their conformal anomaly coefficients. We also provide strong evidence for similar relations between appropriately defined free energies for RG flows between odd-dimensional theories in the large $N$ limit. Holographically, these RG flows across dimensions are described by asymptotically AdS black branes in a gauged supergravity theory, which we exhibit explicitly. We also discuss the uplift of these solutions to string and M-theory and comment on how the entropy of such black branes is captured by the dual field theory.Comment: 64 pages, 2 figures; v2: additional comments and references, typos fixe

On gauged linear sigma models with torsion

We study a broad class of two dimensional gauged linear sigma models (GLSMs) with off-shell N=(2,2) supersymmetry that flow to nonlinear sigma models (NLSMs) on noncompact geometries with torsion. These models arise from coupling chiral, twisted chiral, and semichiral multiplets to known as well as to a new N=(2,2) vector multiplet, the constrained semichiral vector multiplet (CSVM). We discuss three kinds of models, corresponding to torsionful deformations of standard GLSMs realizing Kahler, hyperkahler, and Calabi-Yau manifolds. The (2,2) supersymmetry guarantees that these spaces are generalized Kahler. Our analysis of the geometric structure is performed at the classical level, but we also discuss quantum aspects such as R-symmetry anomalies. We provide an explicit example of a generalized Kahler structure on the conifold.Comment: 39 pages, 1 figure. v2: References adde

Non-toric Cones and Chern-Simons Quivers

We obtain an integral formula for the volume of non-toric tri-Sasaki Einstein manifolds arising from nonabelian hyperkahler quotients. The derivation is based on equivariant localization and generalizes existing formulas for Abelian quotients, which lead to toric manifolds. The formula is particularly valuable in the context of AdS$_{4}\times Y_{7}$ vacua of M-theory and their field theory duals. As an application, we consider 3d $\mathcal N=3$ Chern-Simons theories with affine ADE quivers. While the $\widehat A$ series corresponds to toric $Y_{7}$, the $\widehat D$ and $\widehat E$ series are non-toric. We compute the volumes of the corresponding seven-manifolds and compare to the prediction from supersymmetric localization in field theory, finding perfect agreement. This is the first test of an infinite number of non-toric AdS$_4$/CFT$_3$ dualities.Comment: 2+24 pages. v2: Minor improvements to the text. Matches published versio

Kagome lattice antiferromagnets and Dzyaloshinsky-Moriya interactions

We study the consequences of in-plane (D_p) and out-of-plane (D_z) Dzyaloshinsky-Moriya (DM) interactions on the thermodynamic properties of spin-1/2} Heisenberg model on the kagome lattice using numerical linked cluster expansions and exact diagonalization, and contrast them with those of other perturbations such as exchange anisotropy and dilution. We find that different combinations of the DM anisotropies lead to a wide variety of thermodynamic behavior, which are quite distinct from those of most other perturbations. We argue that the sudden upturn seen experimentally in the susceptibility of the material ZnCu3(OH)6Cl2 can be understood in terms of Dzyaloshinsky-Moriya anisotropies with D_p>|D_z|. We also show that the measured specific heat of the material puts further constraints on the allowed DM parameters.Comment: 12 pages, 15 figures. Content, references, and comments on recent experiments have been added. Published versio