Holography for field theory solitons

We extend a well-known D-brane construction of the AdS/dCFT correspondence to non-abelian defects. We focus on the bulk side of the correspondence and show that there exists a regime of parameters in which the low-energy description consists of two approximately decoupled sectors. The two sectors are gravity in the ambient spacetime, and a six-dimensional supersymmetric Yang-Mills theory. The Yang-Mills theory is defined on a rigid AdS_4 x S^2 background and admits sixteen supersymmetries. We also consider a one-parameter deformation that gives rise to a family of Yang-Mills theories on asymptotically AdS_4 x S^2 spacetimes, which are invariant under eight supersymmetries. With future holographic applications in mind, we analyze the vacuum structure and perturbative spectrum of the Yang-Mills theory on AdS_4 x S^2, as well as systems of BPS equations for finite-energy solitons. Finally, we demonstrate that the classical Yang-Mills theory has a consistent truncation on the two-sphere, resulting in maximally supersymmetric Yang-Mills on AdS_4.Comment: 78 pages plus appendices, 4 figures; v2: references added; v3: typos corrected, published versio

Supersymmetry of the D3/D5 Defect Field Theory

Four-dimensional N=4 super Yang-Mills, with a codimension-one defect breaking half of the supersymmetry, arises as the field theory description of the D3/D5 intersection in the holographic limit. This is one of the earliest, most extensively studied, and commonly used systems in holography. In this note we give the full R-symmetry-covariant supersymmetry variations for this system. We also provide the supercurrents and compute the algebra of the corresponding supercharges, obtaining the full set of central charges. We show that magnetically charged finite-energy field configurations preserving half of the supersymmetry are solutions to a new form of the extended Bogomolny equations, in which the defect fields play the role of jumping data for the Nahm-like part of the equations. In the appendices, we explain the connection between our results and the superspace-based formulations in the literature.Comment: 32 pages, 1 figure, 1 table. In v3: additional section added describing preliminary application of results to BPS solitons; references adde

Setting the scale of the p p and p bar p total cross sections using AdS/QCD

This paper is an addendum to our earlier paper \cite{pom} where we computed the Pomeron contribution to $p ~ p$ and $p ~ \bar p$ scattering in AdS/QCD. The model of \cite{pom} depends on four parameters: the slope and intercept of the Pomeron trajectory $\alpha'_c, \alpha_c(0)$, a mass scale $M_d$ which determines a form factor entering into matrix elements of the energy-momentum tensor, and a coupling $\lambda_{\cal P}$ between the lightest spin $2$ glueball and the proton which sets the overall scale of the total cross section. Here we perform a more detailed computation of $\lambda_{\cal P}$ in the Sakai-Sugimoto model using the construction of nucleons as instantons of the dual 5d gauge theory and an effective 5d fermion description of these nucleons which has been successfully used to compute a variety of nucleon-meson couplings. We find $\lambda_{\cal P,{\rm SS}} \simeq 6.38 ~ {\rm GeV}^{-1}$ which is in reasonable agreement with the value $\lambda_{{\cal P},{\rm fit}} = 8.28 ~ {\rm GeV}^{-1}$ determined by fitting single Pomeron exchange to data.Comment: 8 page