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Diego Rodriguez-Gomez

Publications and source records attributed to Diego Rodriguez-Gomez.

88 records · Page 5Linked to original sources

N-ification of Forces: A Holographic Perspective on D-brane Model Building

We study geometric aspects of extensions of the supersymmetric standard model that exhibit a periodic duality cascade. Via the holographic correspondence, the growth of the gauge group rank towards the UV is interpreted as a gradual decompactification transition. We show that this class of models typically develop a duality wall in the UV, and present an efficient method for estimating the hierarchy between the on-set of the cascade and the formation of the wall. As an illustrative example, we study the model introduced by Cascales, Saad and Uranga in [14], which has an known geometric realization in terms of D-branes on an SPP/Z_3 singularity.

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Holographic flavor in theories with eight supercharges

We review the holographic duals of gauge theories with eight supercharges obtained by adding very few flavors to pure supersymmetric Yang-Mills with sixteen supercharges. Assuming a brane-probe limit, the gravity duals are engineered in terms of probe branes (the so-called flavor brane) in the background of the color branes. Both types of branes intersect on a given subspace in which the matter is confined. The gauge theory dual is thus the corresponding flavoring of the gauge theory with sixteen supercharges. Those theories have in general a non-trivial phase structure; which is also captured in a beautiful way by the gravity dual. Along the lines of the gauge/gravity duality, we review also some of the results on the meson spectrum in the different phases of the theories.

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A KK-monopole giant graviton in AdS_5 x Y_5

We construct a new giant graviton solution in AdS_5 x Y_5, with Y_5 a quasi-regular Sasaki-Einstein manifold, consisting on a Kaluza-Klein monopole wrapped around the Y_5 and with its Taub-NUT direction in AdS_5. We find that this configuration has minimal energy when put in the centre of AdS_5, where it behaves as a massless particle. When we take Y_5 to be S^5, we provide a microscopical description in terms of multiple gravitational waves expanding into the fuzzy S^5 defined as an S^1 bundle over the fuzzy CP^2. Finally we provide a possible field theory dual interpretation of the construction.

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Holographic flavor on the Higgs branch

In this paper we study the holographic dual, in several spacetime dimensions, of the Higgs branch of gauge theories with fundamental matter. These theories contain defects of various codimensionalities, where the matter fields are located. In the holographic description the matter is added by considering flavor brane probes in the supergravity backgrounds generated by color branes, while the Higgs branch is obtained when the color and flavor branes recombine with each other. We show that, generically, the holographic dual of the Higgs phase is realized by means of the addition of extra flux on the flavor branes and by choosing their appropriate embedding in the background geometry. This suggests a dielectric interpretation in terms of the color branes, whose vacuum solutions precisely match the F- and D-flatness conditions obtained on the field theory side. We further compute the meson mass spectra in several cases and show that when the defect added has codimension greater than zero it becomes continuous and gapless.

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Adding magnetic flux to the baryon vertex

We generalise the baryon vertex configuration of AdS/CFT by adding magnetic field on its worldvolume, dissolving D-string charge. A careful analysis of the configuration shows that there is an upper bound on the number of dissolved strings. We provide a microscopical description of this configuration in terms of a dielectric effect for the dissolved strings.

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Pp-wave Matrix Models from Point-like Gravitons

The BFSS Matrix model can be regarded as a theory of coincident M-theory gravitons. In this spirit, we summarize how using the action for coincident gravitons proposed in hep-th/0207199 it is possible to go beyond the linear order approximation of Kabat and Taylor, and to provide a satisfactory microscopical description of giant gravitons in $AdS_m\times S^n$ backgrounds. We then show that in the M-theory maximally supersymmetric pp-wave background, the action for coincident gravitons, besides reproducing the BMN Matrix model, predicts a new quadrupolar coupling to the M-theory 6-form potential, which supports the so far elusive fuzzy 5-sphere giant graviton solution. Finally, we discuss similar Matrix models that can be derived in Type II string theories using dualities.

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The baryon vertex with magnetic flux

In this letter we generalise the baryon vertex configuration of AdS/CFT by adding a suitable instantonic magnetic field on its worldvolume, dissolving D-string charge. A careful analysis of the configuration shows that there is an upper bound on the number of dissolved strings. This should be a manifestation of the stringy exclusion principle. We provide a microscopical description of this configuration in terms of a dielectric effect for the dissolved strings.

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Mesons and Higgs branch in defect theories

We consider the defect theory obtained by intersecting D3- and D5-branes along two common spatial directions. We work in the approximation in which the D5-brane is a probe in the AdS_5xS^5 background. By adding worldvolume flux to the D5-brane and choosing an appropriate embedding of the probe in AdS_5xS^5, one gets a supersymmetric configuration in which some of the D3-branes recombine with the D5-brane. We check this fact by showing that the D5-brane can be regarded as a system of polarized D3-branes. On the field theory side this corresponds to the Higgs branch of the defect theory, where some of the fundamental hypermultiplet fields living on the intersection acquire a vacuum expectation value. We study the spectrum of mesonic bound states of the defect theory in this Higgs branch and show that it is continuous and gapless.

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Computing Wilson lines with dielectric branes

Wilson lines in N=4SYM can be computed in terms of branes carrying electric flux, i.e. F-strings dissolved in their worldvolumes. It is then natural to think that those configurations are the effective description of strings expanding due to dielectric effect to D-branes. In this note we explicitly show this for a class of such configurations, namely those dual to Wilson lines either in the symmetric or in the antisymmetric tensor product of fundamentals.

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Type II pp-wave Matrix Models from Point-like Gravitons

The BMN Matrix model can be regarded as a theory of coincident M-theory gravitons, which expand by Myers dielectric effect into the 2-sphere and 5-sphere giant graviton vacua of the theory. In this note we show that, in the same fashion, Matrix String theory in Type IIA pp-wave backgrounds arises from the action for coincident Type IIA gravitons. In Type IIB, we show that the action for coincident gravitons in the maximally supersymmetric pp-wave background gives rise to a Matrix model which supports fuzzy 3-sphere giant graviton vacua with the right behavior in the classical limit. We discuss the relation between our Matrix model and the Tiny Graviton Matrix theory of hep-th/0406214.

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Branes wrapping black holes as a purely gravitational dielectric effect

In this paper we give a microscopical description of certain configurations of branes wrapping black hole horizons in terms of dielectric gravitational waves. Interestingly, the configurations are stable only due to the gravitational background. Therefore, this constitutes a nice example of purely gravitational dielectric effect.

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Fuzzy 5-spheres and pp-wave Matrix Actions

Using the action describing N coincident gravitational waves in M-theory we construct a pp-wave Matrix model cointaning a fuzzy 5-sphere giant graviton solution. This fuzzy 5-sphere is constructed as a U(1) fibration over a fuzzy $CP^2$, and has the correct dependence of the radius with the light-cone momentum, $r^4\sim p^+$, to approach the 5-sphere giant graviton solution of Mc.Greevy et al in the large N limit.

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Giant Gravitons in AdS_3 x S^3 x T^4 as Fuzzy Cylinders

Using the non-Abelian action for coincident Type IIB gravitational waves proposed in hep-th/0303183 we show that giant gravitons in the AdS_3 x S^3 x T^4 background can be described in terms of coincident waves expanding into a fuzzy cylinder, spanned by two embedding scalars and one worldvolume scalar. This fuzzy cylinder has dipole and magnetic moments with respect to the 2-form and 6-form potentials of the background, and can be interpreted as a bound state of D1-branes and D5-branes (wrapped on the 4-torus) wrapped around the basis of the cylinder. We show the exact agreement between this description and the Abelian, macroscopical description given in the literature.

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Giant Gravitons and Fuzzy CP^2

In this article we describe the giant graviton configurations in AdS_m x S^n backgrounds that involve 5-spheres, namely, the giant graviton in AdS_4 x S^7 and the dual giant graviton in AdS_7 x S^4, in terms of dielectric gravitational waves. Thus, we conclude the programme initiated in hep-th/0207199 and pursued in hep-th/0303183 and hep-th/0406148 towards the microscopical description of giant gravitons in AdS_m x S^n spacetimes. In our construction the gravitational waves expand due to Myers dielectric effect onto fuzzy 5-spheres which are described as S^1 bundles over fuzzy CP^2. These fuzzy spheres appear as solutions of the matrix model that comes up as the action for M-theory gravitational waves. The validity of our description is checked by confirming the agreement with the Abelian description in terms of a spherical M5-brane when the number of waves goes to infinity.

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Giant Gravitons as Fuzzy Manifolds

Giant gravitons are described microscopically in terms of dielectric gravitational waves expanding into fuzzy manifolds. We review these constructions in AdS_m \times S^n spacetimes, discussing the different fuzzy manifolds that appear in each case.

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A Microscopical Description of Giant Gravitons II: The AdS_5 x S^5 Background

In this article we continue with the microscopical investigation of giant graviton configurations in AdS_m x S^n spacetimes, initiated in hep-th/0207199. Using dualities and a Matrix theory derivation we propose an action that describes multiple Type IIB gravitons. This action contains multipole moment couplings to the Type IIB background potentials. Using these couplings, we study, from the microscopical point of view, the giant graviton and dual giant graviton configurations in the AdS_5 x S^5 background. In both cases the gravitons expand into a non-commutative 3-sphere, that is defined as an S^1-bundle over a fuzzy 2-sphere. When the number of gravitons is large we find perfect agreement with the Abelian, macroscopical description of giant gravitons in this spacetime, given in the literature.

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