November 25, 2002
We study a defect conformal field theory describing D3-branes intersecting over two space-time dimensions. This theory admits an exact Lagrangian description which includes both two- and four-dimensional degrees of freedom, has (4,4) supersymmetry and is invariant under global conformal transformations. Both two- and four-dimensional contributions to the action are conveniently obtained in a two-dimensional (2,2) superspace. In a suitable limit, the theory has a dual descript...
July 20, 2006
We construct supersymmetric D-brane probe solutions in the background of the 2-charge D1-D5 system on M, where M is either K3 or T^4. We focus on `near-horizon bound states' that preserve supersymmetries of the near-horizon AdS_3 x S^3 x M geometry and are static with respect to the global time coordinate. We find a variety of half-BPS solutions that span an AdS_2 subspace in AdS_3, carry worldvolume flux and can wrap an S^2 within S^3 and/or supersymmetric cycles in M.
June 7, 2014
In this paper, we study the M5-brane configurations in AdS$_4 \times Q^{1,1,1}$ spacetime. We consider the configurations with an AdS$_2$ factor embedding into AdS$_4$, and manage to construct two solutions, which could be dual to line defects in the boundary gauge theory. Moreover we discuss their BPS nature and find that neither of them is supersymmetric. We show that the M5-brane with a R$_t$ or an AdS$_3$ factor found before is half-BPS.
June 12, 1998
We find the space-time supersymmetric and kappa-invariant action for a D3-brane propagating in the AdS_5 x S^5 background. As in the previous construction of the fundamental string action in this maximally supersymmetric string vacuum the starting point is the corresponding superalgebra su(2,2|4). We comment on the super Yang-Mills interpretation of the gauge-fixed form of the action.
May 1, 2003
We investigate an AdS_4 x L_2 D5-brane in AdS_5 x X_5 space-time, in the context of AdS/dCFT correspondence. Here, X_5 is a Sasaki-Einstein manifold and L_2 is a submanifold of X_5. This brane has the same supersymmetry as the 3-dimensional N=1 superconformal symmetry if L_2 is a special Legendrian submanifold in X_5. In this case, this brane is supposed to correspond to a superconformal wall defect in 4-dimensional N=4 super Yang-Mills theory. We construct these new string b...
July 20, 2007
We derive a geometrical characterisation of a large class of AdS_3 and AdS_2 supersymmetric spacetimes in IIB supergravity with non-vanishing five-form flux using G-structures. These are obtained as special cases of a class of supersymmetric spacetimes with an $\mathbb{R}^{1,1}$ or $\mathbb{R}$ (time) factor that are associated with D3-branes wrapping calibrated 2- or 3- cycles, respectively, in manifolds with SU(2), SU(3), SU(4) and G_2 holonomy. We show how two explicit AdS...
June 18, 2019
We consider defects in 5d field theories corresponding to higher-rank generalizations of the $E_{N_f+1}$ theories; holographically dual to the Brandhuber-Oz background in type I' String Theory. We concentrate on codimension 2 and 1 defects, corresponding, respectively, to 3d and 4d defect Quantum Field Theories. We study holographically such defect theories by considering supersymmetric probe D4- and D6-branes in the $AdS_6$, whose fluctuations allow us to study the spectrum ...
May 26, 2006
We study supersymmetric embeddings of D-brane probes of different dimensionality in the AdS_5xL^{abc} background of type IIB string theory. In the case of D3-branes, we recover the known three-cycles dual to the dibaryonic operators of the gauge theory and we also find a new family of supersymmetric embeddings. Supersymmetric configurations of D5-branes, representing fractional branes, and of spacetime filling D7-branes (which can be used to add flavor) are also found. Stable...
April 25, 2007
We study supersymmetric branes in AdS_7 x S^4 and AdS_4 x S^7. We show that in the former case the membranes should be viewed as M5 branes with fluxes and we identify two types of such fivebranes (they are analogous to giant gravitons and to dual giants). In AdS_4 x S^7 we find both M5 branes with fluxes and freestanding stacks of membranes. We also go beyond probe approximation and construct regular supergravity solutions describing geometries produced by the branes. The met...
October 23, 2002
We show the existence of classical solutions of a system of D3-branes oriented at an arbitrary angle with respect to each other, in a six dimensional pp-wave background obtained from AdS_3\times S^3\times R^4, with NS-NS and R-R 3-form field strength. These D-brane bound states are shown to preserve 1/16 of the supersymmetries. We also present more D-brane bound state solutions by applying T-duality symmetries. Finally, the probe analysis is discussed along with a brief outli...