Hawking and Page on the brane

We show that the Hawking-Page phase transition of a CFT on AdS_{d-1} weakly coupled to gravity has a dual bulk description in terms of a phase transition between a black string and a thermal gas on AdS_{d}. At even lower temperatures the black string develops a Gregory Laflamme instability, which is dual to black hole evaporation in the boundary theory.Comment: 8 pages, 1 figure; v2: typos in some formulas corrected; v3: discussion improve

Notes on Properties of Holographic Matter

Probe branes with finite worldvolume electric flux in the background created by a stack of Dp branes describe holographically strongly interacting fundamental matter at finite density. We identify two quantities whose leading low temperature behavior is independent of the dimensionality of the probe branes: specific heat and DC conductivity. This behavior can be inferred from the dynamics of the fundamental strings which provide a good description of the probe branes in the regime of low temperatures and finite densities. We also comment on the speed of sound on the branes and the temperature dependence of DC conductivity at vanishing charge density.Comment: 18 pages, 2 figures; v2: corrected error in Section 6, conclusions unchanged; v3: improved figures and added clarifying comment

Localizing global hedgehogs on the brane

We investigate the localization of 4D topological global defects on the brane embedded in 5D. The defects are induced by 5D scalar fields with a symmetry-breaking potential. Taking an ansatz which separates the scalar field into the 4D and the extra-D part, we find that the static-hedgehog configuration is accomplished and the defects are formed only in the $AdS_4/AdS_5$ background. In the extra dimension, the localization amplitude for the 4D defects is high where the warp factor is high.Comment: 17 pages, revte

Bulk metric of brane world models and submanifolds in 6D pseudo-Euclidean space-time

In this short note, five-dimensional brane world models with dS_{4} metric on the branes are discussed. The explicit coordinate transformations, which show the equivalence between the bulk metric of these brane world models and the metric induced on an appropriate submanifolds in the flat six-dimensional pseudo-Euclidean space-time, are presented. The cases of the zero and non-zero cosmological constant in the bulk are discussed in detail.Comment: 5 pages, typos correcte

Electric-Magnetic Duality and Topological Insulators

We work out the action of the SL(2,Z) electric-magnetic duality group for an insulator with a non-trivial permittivity, permeability and theta-angle. This theory has recently been proposed to be the correct low-energy effective action for topological insulators. As applications, we give manifestly SL(2,Z) covariant expressions for the Faraday rotation at orthogonal incidence at the interface of two such materials, as well as for the induced magnetic and electric charges, slightly clarifying the meaning of expressions previously derived in the literature. We also use electric-magnetic duality to find a gravitational dual for a strongly coupled version of this theory using the AdS/CFT correspondence.Comment: 4 pages; version accepted by PR

Hadron Masses and Screening from AdS Wilson Loops

We show that in strongly coupled N=4 SYM the binding energy of a heavy and a light quark is independent of the strength of the coupling constant. As a consequence we are able to show that in the presence of light quarks the analog of the QCD string can snap and color charges are screened. The resulting neutral mesons interact with each other only via pion exchange and we estimate the massesComment: 4 pages, revte

Surface Plasmons and Topological Insulators

We study surface plasmons localized on interfaces between topologically trivial and topologically non-trivial time reversal invariant materials in three dimensions. For the interface between a metal and a topological insulator the magnetic polarization of the surface plasmon is rotated out of the plane of the interface; this effect should be experimentally observable by exciting the surface plasmon with polarized light. More interestingly, we argue that the same effect also is realized on the interface between vacuum and a doped topological insulator with non-vanishing bulk carrier density.Comment: 6 pages, 1 figure; v2: typo in eq. (27) correcte