We obtain the supergravity dual of N=1 supersymmetric gauge theory in 2+1 dimensions with a large number of unquenched massless flavors. The geometries found are obtained by solving the equations of motion of supergravity coupled to a suitable continuous distribution of flavor branes. The background obtained preserves two supersymmetries. We find that when N_c\ge 2N_f the behavior of the solutions is compatible with having an asymptotically free dual gauge theory with dynamical quarks. On the contrary, when N_c<2N_f the theory develops a Landau pole in the UV. We also find a new family of (unflavored) backgrounds generated by D5-branes that wrap a three-cycle of a cone with G_2 holonomy.
Using AdS/CFT, we study the addition of an arbitrary number of backreacting flavors to the Klebanov-Witten theory, making many checks of consistency between our new Type IIB plus branes solution and expectations from field theory. We study generalizations of our method for adding flavors to all N=1 SCFTs that can be realized on D3-branes at the tip of a Calabi-Yau cone. Also, general guidelines suitable for the addition of massive flavor branes are developed.
We construct the string duals of the defect theories generated when N_f flavor D5-branes intersect N_c color D3-branes along a 2+1 dimensional subspace. We work in the Veneziano limit in which N_c and N_f are large and N_f/N_c is fixed. By smearing the D5-branes, we find supergravity solutions that take into account the backreaction of the flavor branes and preserve two supercharges. When the flavors are massless the resulting metric displays an anisotropic Lifshitz-like scale invariance. The case of massive quarks is also considered.
Within the AdS/CFT correspondence, we review the studies of field theories with a large number of adjoint and fundamental fields, in the Veneziano limit. We concentrate in set-ups where the fundamentals are introduced by a smeared set of D-branes. We make emphasis on the general ideas and then in subsequent chapters that can be read independently, describe particular considerations in various different models. Some new material is presented along the various sections.
The addition of fundamental degrees of freedom to a theory which is dual (at low energies) to N=2 SYM in 1+3 dimensions is studied. The gauge theory lives on a stack of Nc D5 branes wrapping an S^2 with the appropriate twist, while the fundamental hypermultiplets are introduced by adding a different set of Nf D5-branes. In a simple case, a system of first order equations taking into account the backreaction of the flavor branes is derived (Nf/Nc is kept of order 1). From it, the modification of the holomorphic coupling is computed explicitly. Mesonic excitations are also discussed.
We find solutions of type IIA supergravity which are dual to three-dimensional Chern-Simons-matter theories with unquenched fields in the fundamental representation of the gauge group (flavors). In the holographic dual the addition of flavor is performed by means of D6-branes that are extended along the Minkowski gauge theory directions and are delocalized in the internal space in such a way that the system is N=1 supersymmetric and the flavor group is abelian. For massless flavors the corresponding geometry has the form of a product space AdS_4x M_6, where M_6 is a six-dimensional compact man…
We present an analytic solution of type IIB supergravity plus D7-branes, describing the addition of any number of flavors to the Klebanov-Strassler background. The dual field theory and its self-similar RG flow, described by a cascade of Seiberg dualities also in the presence of flavors, are discussed. The solution indicates that the dual gauge theory enjoys a duality wall in the UV. We stress the correspondence between Seiberg duality on the field theory side, and large gauge transformations on the RR and NSNS potentials on the gravity side. This contribution is mostly based on arxiv:0706.123…
We construct the gravity duals of the Higgs branches of three-dimensional (four-dimensional) super Yang-Mills theories coupled to $N_\textrm{f}$ quark flavors. The effect of the quarks on the color degrees of freedom is included, and corresponds on the gravity side to the backreaction of $N_\textrm{f}$ flavor D6-branes (D7-branes) on the background of $N_\textrm{c}$ color D2-branes (D3-branes). The Higgsing of the gauge group arises from the dissolution of some color branes inside the flavor branes. The dissolved color branes are represented by non-Abelian instantons whose backreaction is also…
We construct a holographic dual to the three-dimensional ABJM Chern-Simons matter theory with unquenched massive flavors. The flavor degrees of freedom are introduced by means of D6-branes extended along the gauge theory directions and delocalized in the internal space. To find the solution we have to solve the supergravity equations of motion with the source terms introduced by the D6-branes. The background we get is a running solution representing the renormalization group flow between two fixed points, at the IR and the UV, in both of which the geometry is of the form AdS_4 x M_6, where M_6…
We construct analytically the gravity duals of three-dimensional, super Yang-Mills-type theories with $\mathcal N=1$ supersymmetry coupled to $N_f$ quark flavors. The backreaction of the quarks on the color degrees of freedom is included, and corresponds on the gravity side to the backreaction of $N_f$ D6-branes on the background of $N$ D2-branes. The D6-branes are smeared over the compact part of the geometry, which must be a six-dimensional nearly Kähler manifold in order to preserve supersymmetry. For massless quarks, the solutions flow in the IR to an $AdS_4$ fixed point dual to a Chern-Si…
We construct a black hole geometry generated by the intersection of $N_c$ color D3- branes and $N_f$ flavor D5-branes along a 2+1 dimensional subspace. Working in the Veneziano limit in which $N_f$ is large and distributing homogeneously the D5-branes in the internal space, we calculate the solution of the equations of motion of supergravity plus sources which includes the backreaction of the flavor branes. The solution is analytic and dual to a 2+1 dimensional defect in a 3+1 dimensional gauge theory, with $N_f$ massless hypermultiplets living in the defect. The smeared background we obtain c…
We study (non-)integrability and the presence of chaos in gravity dual backgrounds of strongly coupled gauge theories with unquenched flavor, specifically of the four-dimensional N=2 super Yang-Mills theory and the three-dimensional ABJM theory. By examining string motion on the geometries corresponding to backreacted D3/D7 and D2/D6 systems, we show that integrable theories with quenched flavor become non-integrable when the virtual quark loops are taken into account. For the string solutions in the backreacted D3/D7 system, we compute the leading Lyapunov exponent which turns out to saturate…
We propose a string dual to the SU(Nc) N=4 SYM coupled to Nf massless fundamental flavors in an external magnetic field. The flavors are introduced by homogeneously smeared Nf D7-branes and the external magnetic field via a non-trivial Kalb-Ramond B-field. Our solution is perturbative in a parameter that counts the number of internal flavor loops. In the limit of vanishing B-field the background reduces to the supersymmetric one obtained in hep-th/0612118. We introduce an additional probe D7--brane and in the supersymmetric limit of vanishing B-field perform a holographic renormalization of it…
We study, in a holographic setup, the effect of adding localized fermionic impurities to the three-dimensional Chern-Simons-matter theories with unquenched fields in the fundamental representation of the gauge group. The impurities are introduced as probe D6-branes extending along the radial direction and wrapping a five-dimensional submanifold inside a squashed CP^3. We analyze the straight flux tube embeddings and study the corresponding fluctuation modes of the D6-branes. The conformal dimensions of the operators dual to such fluctuations depend non-trivially on the ratio of the flavor numb…
We review the construction of gravitational solutions holographically dual to N=1 quiver gauge theories with dynamical flavor multiplets. We focus on the D3-D7 construction and consider the finite temperature, finite quark chemical potential case where there is a charged black hole in the dual solution. Discussed physical outputs of the model include its thermodynamics (with susceptibilities) and general hydrodynamic properties.
We study various aspects of the matrix models calculating free energies and Wilson loop observables in supersymmetric Chern-Simons-matter theories on the three-sphere. We first develop techniques to extract strong coupling results directly from the spectral curve describing the large N master field. We show that the strong coupling limit of the gauge theory corresponds to the so-called tropical limit of the spectral curve. In this limit, the curve degenerates to a planar graph, and matrix model calculations reduce to elementary line integrals along the graph. As an important physical applicati…
We construct the supergravity solution for fully localized D2/D6 intersection. The near horizon limit of this solution is the supergravity dual of supersymmetric Yang-Mills theory in 2+1 dimensions with flavor. We use this solution to formulate mirror symmetry of 2+1 dimensional gauge theories in the language of AdS/CFT correspondence. We also construct the supergravity dual of a non-commutative gauge theory with fundamental matter.
We obtain gravity duals to supersymmetric gauge theories in two and three spacetime dimensions with unquenched flavor. The supergravity solutions are generated by a set of color branes wrapping a compact cycle in a Calabi-Yau threefold, together with another set of flavor branes extended along the directions orthogonal to the cycle wrapped by the color branes. We construct supergravity backgrounds which include the backreaction induced by a smeared set of flavor branes, which act as delocalized dynamical sources of the different supergravity fields.
We incorporate massive flavored fundamental quarks in the supergravity dual of N=1 SYM by introducing D7 brane probes to the Klebanov Strassler background. We find probe configurations that solve the D7 equations of motion. We compute the quadratic fluctuations of the D7 brane and extract the spectrum of vector and pseudo scalar flavored mesons. The spectra found are discrete and exhibit a mass gap of the order of the glueball mass.
We study the glueballs in a four-dimensional ${\cal N}=2$ super Yang-Mills theory with fundamental matters in terms of the supergravity dual. The supergravity background is constructed by $N$ D3 brane with a probe D7 brane. We numerically compute the glueball masses for $0^{++}$ and $1^{--}$ in the background. We find that the mass ratio of $0^{++}$ glueballs is mostly in agreement with the lattice calculations. We compare the glueball masses with the meson masses. The mass ratio $M_{GB}/M_{meson}$ is calculated with 1.4. If the mass $M_{GB}$ is set to $1.6 GeV$, the meson mass $M_{meson}$ is …
We employ the string/gauge theory correspondence to study properties of strongly coupled quark-gluon plasmas in thermal gauge theories with a large number of colors and flavors. In particular, we analyze non-critical string duals of conformal (S)QCD, as well as ten dimensional wrapped fivebrane duals of SQCD-like theories. We study general properties of the dual plasmas, including the drag force exerted on a probe quark and the jet quenching parameter. We find that these plasma observables depend on the number of colors and flavors in the ``QCD dual''; in particular, we find that the jet quenc…
The microscopic spectral density of the QCD Dirac operator at nonzero baryon chemical potential for an arbitrary number of quark flavors was derived recently from a random matrix model with the global symmetries of QCD. In this paper we show that these results and extensions thereof can be obtained from the replica limit of a Toda lattice equation. This naturally leads to a factorized form into bosonic and fermionic QCD-like partition functions. In the microscopic limit these partition functions are given by the static limit of a chiral Lagrangian that follows from the symmetry breaking patter…
We argue for the quantum-gravitational inconsistency of certain 6d $\mathcal{N}=(1,0)$ supergravity theories, whose anomaly-free gauge algebra $\mathfrak{g}$ and hypermultiplet spectrum $M$ were observed in arxiv:2012.01437 to be realizable only as part of a larger gauge sector $(\mathfrak{g}' \supset \mathfrak{g}, M' \supset M)$ in F-theory. To detach any reference to a string theoretic method of construction, we utilize flavor symmetries to provide compelling reasons why the vast majority of such $(\mathfrak{g},M)$ theories are not compatible with quantum gravity constraints, and how the "au…
We construct holographic duals to N=1 SQCD with a quartic superpotential and unquenched massive flavors. Our backgrounds are generated by D5-branes wrapping two-dimensional submanifolds of an internal space. The flavor degrees of freedom are introduced by means of D5-branes extended along two-dimensional calibrated surfaces, and act as sources of the different supergravity fields. The backgrounds we get include the backreaction of the flavor branes and generalize the geometries obtained so far to the case in which the fundamental matter is massive. The supergravity solutions we find are regula…
We perform a comprehensive and systematic analysis of the SUSY flavor structure of generic 5D supergravity models on $S^1/Z_2$ with multiple $Z_2$-odd vector multiplets that generate multiple moduli. The SUSY flavor problem can be avoided due to contact terms in the 4D effective Kähler potential peculiar to the multi-moduli case. A detailed phenomenological analysis is provided based on an illustrative model.
Aharony, Bergman, Jafferis, and Maldacena have proposed that the low-energy description of multiple M2-branes at a C4/Zk singularity is a (2+1)-dimensional N=6 supersymmetric U(Nc) x U(Nc) Chern-Simons matter theory, the ABJM theory. In the large-Nc limit, its holographic dual is supergravity in AdS4 x S7/Zk. We study various ways to add fields that transform in the fundamental representation of the gauge groups, i.e. flavor fields, to the ABJM theory. We work in a probe limit and perform analyses in both the supergravity and field theory descriptions. In the supergravity description we find a…
We study the addition of flavor to the gravity dual of N=4 three-dimensional gauge theories obtained by wrapping $N_c$ D4-branes on a two-cycle of a non-compact Calabi-Yau two-fold. In this setup the flavor is introduced by adding another set of D4-branes that are extended along the non-compact directions of the Calabi-Yau which are normal to the cycle which the color branes wrap. The analysis is performed both in the quenched and unquenched approximations. In this latter case we compute the backreacted metric and we show that it reproduces the running of the gauge coupling. The meson spectrum…
We determine the general structure of quantum anomalies for the $R$-multiplet of four dimensional $\mathcal{N}=1$ supersymmetric quantum field theories in the presence of background fields for an arbitrary number of Abelian flavor multiplets. By solving the Wess-Zumino consistency conditions for off-shell new minimal supergravity in four dimensions with an arbitrary number of Abelian vector multiplets, we compute the anomaly in the conservation of the supercurrent to leading non trivial order in the gravitino and vector multiplet fermions. We find that both $R$-symmetry and flavor anomalies ne…
We construct gravity duals to supersymmetric gauge theories in the presence of unquenched flavor hypermultiplets in the fundamental representation of the gauge group living on the (1+1)-dimensional defect. This configuration is given by the intersection of two sets of D3-branes. Working in the Veneziano limit with large number of colors and flavors we are able to find a closed set of equations describing the dual geometry. We briefly discuss the corresponding solutions for massless flavors as well as in the small flavor limit of massive hypermultiplets. Interestingly, the 1/4-BPS supergravity …
In this thesis we review some results on the generalization of the gauge/gravity duality to new cases by using T-duality and by including fundamental matter, finding applications to condensed matter physics. First, we construct new supersymmetric solutions of type IIA/B and eleven-dimensional supergravity by using non-abelian T-duality. Second, we construct a type IIA supergravity solution with D6-brane sources, dual to an unquenched massive flavored version of the ABJM theory. Third, we study a probe D6-brane with worldvolume gauge fields in the ABJM background, obtaining the dual description…
We study 5-dimensional supergravity on S^1/Z_2 with a physical Z_2-odd vector multiplet, which yields an additional modulus other than the radion. We derive 4-dimensional effective theory and find additional terms in the Kahler potential that are peculiar to the multi moduli case. Such terms can avoid tachyonic soft scalar masses at tree-level, which are problematic in the single modulus case. We also show that the flavor structure of the soft terms are different from that in the single modulus case when hierarchical Yukawa couplings are generated by wavefunction localization in the fifth dime…
We consider several solutions of supergravity with reduced supersymmetry which are related to wrapped branes, and elaborate on their geometrical and physical interpretation. The Killing spinors are computed for each configuration. In particular, all the known metrics on the conifold and all G_2 holonomy metrics with cohomogeneity one and S^3xS^3 principal orbits are constructed from D=8 gauged supergravity in a unified formalism. The addition of 4-form fluxes piercing the unwrapped directions is also considered. We also study the problem of finding kappa-symmetric D5-probes in the so-called Ma…
We study the physics of probe D6-branes with quantized internal worldvolume flux in the ABJM background with unquenched massless flavors. This flux breaks parity in the (2+1)-dimensional gauge theory and allows quantum Hall states. Parity breaking is also explicitly demonstrated via the helicity dependence of the meson spectrum. We obtain general expressions for the conductivities, both in the gapped Minkowski embeddings and in the compressible black hole ones. These conductivities depend on the flux and contain a contribution from the dynamical flavors which can be regarded as an effect of in…
We study U(N) SQCD with N_f <= N flavors of quarks and antiquarks by engineering it with a configuration of fractional D3-branes on a C^3 / Z_2 x Z_2 orbifold. In particular we show how the moduli space of the gauge theory naturally emerges from the classical geometry produced by the D3-branes, and how the non-perturbatively generated superpotential is recovered from geometrical data.
We study marginal deformations of a class of three-dimensional $\mathcal{N}=2$ SCFTs that admit a holographic dual description in massive type IIA supergravity. We compute the dimension of the conformal manifold in these SCFTs and identify a special submanifold with enhanced flavor symmetry. We show how to apply the TsT transformation of Lunin-Maldacena to construct explicit supersymmetric AdS$_4$ solutions of massive type IIA supergravity with non-trivial internal fluxes that are the holographic dual of these marginal deformations. Finally, we also briefly comment on a class of RG flows betwe…
We study five-dimensional superconformal field theories and their holographic dual, matter-coupled Romans supergravity. On the one hand, some recently derived formulae allow us to extract the central charges from deformations of the supersymmetric five-sphere partition function, whose large N expansion can be computed using matrix model techniques. On the other hand, the conformal and flavor central charges can be extracted from the six-dimensional supergravity action, by carefully analyzing its embedding into type I' string theory. The results match on the two sides of the holographic duality…
We present new supergravity backgrounds generated by N_c D5-branes, wrapping the S^2 of the resolved conifold, in the presence of N_f = 2 N_c smeared flavor D5-branes. The smearing allows us to take their backreaction on the geometry into account. We discuss the consistency, stability, and supersymmetry of these types of setups. We find near horizon geometries that we expect to be supergravity duals of SQCD-like theories with N_f= 2N_c. From these backgrounds we numerically extract rectangular Wilson loops and beta functions of the dual field theory for the regime where our approximations are …
We consider gravity mediated supersymmetry (SUSY) breaking in 5D spacetime with two 4D branes B1 and B2 separated in the extra dimension. Using an off-shell 5D supergravity (SUGRA) formalism, we argue that the SUSY breaking scales could be non-universal even at the fundamental scale in a brane world setting, since SUSY breaking effects could be effectively localized. As an application, we suggest a model in which the two light chiral MSSM generations reside on B1, while the third generation is located on B2, and the Higgs multiplets as well as gravity and gauge multiplets reside in the bulk. F…
We present a fully backreacted D3-D7 supergravity solution dual to the Klebanov-Strassler cascading gauge theory coupled to a large number of massive dynamical flavors in the Veneziano limit. The mass of the flavors can be larger or smaller than the dynamically generated scale. The solution is always regular at the origin of the radial coordinate and as such it can be suitably employed to explore the rich IR physics of the dual gauge theory. In this paper we focus on the static quark-antiquark potential, the screening of chromoelectric charges induced by the dynamical flavors, the flux tube br…
We propose a brane-world, which contains flavor quarks and mesons, by embedding dimensionally reduced D7-brane in both the supersymmetric and non-supersymmetric 5d background which are obtained as the solutions of type IIB supergravity compactified on Ad$S_5\times S^5$. In the supersymmetric case, the RS brane can be put at any point of the fifth coordinate, but it is pushed to the Ad$S_5$ boundary in the non-supersymmetric case. We study the localization of the flavor mesons, the fluctuation-modes of D7-brane, on the Randall-Sundrum brane in these backgrounds.
We find new supergravity solutions generated by D5-branes wrapping a four-cycle and preserving four and two supersymmetries. We first consider the configuration in which the fivebranes wrap a four-cycle in a Calabi-Yau threefold, which preserves four supersymmetries and is a gravity dual to the Coulomb branch of two-dimensional gauge theories with N=(2,2) supersymmetry. We also study the case of fivebranes wrapping a co-associative four-cycle in a manifold of G_2-holonomy, which provides a gravity dual of N=(1,1) supersymmetric Yang-Mills theory in two dimensions. We also discuss the addition …
Modulus stabilization of modular flavor models in Jordan frame supergravity
School of Physics, Zhengzhou University（郑州大学物理学院）
本文在 Jordan 标架超引力中，通过非最小标量-曲率耦合形式 $Φ(τ,\barτ)R$，结合模不变性、尺度因子正定性和 Kähler 度规正定性，约束标架函数及 Kähler 势，并研究从 Jordan 标架到 Einstein 标架变换后标量势的形状，发现其与普通单模稳定化机制不同，势能在 $i\infty$ 不动点处可能静止导致逃逸型真空，但可通过典型模 VEV 在大 $\Imτ$ 下稳定，最后数值讨论了简化场景下的模稳定化。
Making use of generalized calibrated geometry and G-structures we put the problem of finding string-duals with smeared backreacting flavor branes in a more mathematical setting. This more formal treatment of the problem allows us to easily smear branes without good coordinate representations, establish constraints on the smearing form and identify a topological central charge in the SUSY algebra. After exhibiting our methods for a series of well known examples, we apply them to the problem of flavoring a supergravity-dual to a d=2+1 dimensional N=2 super Yang-Mills-like theory. We find new sol…
We study two related problems in the context of a supergravity dual to N=1 SYM. One of the problems is finding kappa symmetric D5-brane probes in this particular background. The other is the use of these probes to add flavors to the gauge theory. We find a rich and mathematically appealing structure of the supersymmetric embeddings of a D5-brane probe in this background. Besides, we compute the mass spectrum of the low energy excitations of N=1 SQCD (mesons) and match our results with some field theory aspects known from the study of supersymmetric gauge theories with a small number of flavors…
We construct supersymmetric Janus solutions using four-dimensional $N=3$ gauged supergravity with $SO(3)\times SU(3)$ gauge group. The $N=3$ supersymmetric $AdS_4$ vacuum with unbroken $SO(3)\times SU(3)$, identified with the compactification of eleven-dimensional supergravity on $AdS_4\times N^{010}$, provides a gravity dual of supersymmetric $N=3$ Chern-Simons-Matter theory in three dimensions with $SU(3)$ flavor symmetry. The Janus solutions accordingly describe supersymmetric conformal interfaces within this Chern-Simons-Matter theory via the AdS/CFT holography. We find two classes of Janu…
We study the properties of a D6-brane probe in the ABJM background with smeared massless dynamical quarks in the Veneziano limit. Working at zero temperature and non-vanishing charge density, we show that the system undergoes a quantum phase transition in which the topology of the brane embedding changes from a black hole to a Minkowski embedding. In the unflavored background the phase transition is of second order and takes place when the charge density vanishes. We determine the corresponding critical exponents and show that the scaling behavior near the quantum critical point has multiplica…
We investigate the distinction between color- and flavor-branes, that is usually made in the context of gauge/string duality with backreacting flavors. Our remarks are based on a series of examples concerning the role of source terms in relatively simple supergravity backgrounds that allow for a well-controlled approach to the problem. The observations suggest that, in opposite to general practice, one could consider such terms for both kinds of branes, while their presence is only essential for smeared sources - as is commonly the case for flavor-branes. Among the examples studied are D3-D7 s…
We study the holographic dual of the Higgs branch of N=4 SYM in four dimensions coupled to quenched fundamental matter. The fundamentals are added via flavor D7-branes and the Higgs phase is obtained when the color D3-branes and the flavor D7-branes recombine with each other. The holographic dual consists of D7-brane probes in the background generated by the color D3-branes. In this supergravity dual the Higgs phase is realized by switching on a selfdual field strength on the worldvolume of the D7-branes. A complementary microscopic description in terms of dielectric D3-branes is also possible…
In this paper we present new analytic solutions of pure Type IIB supergravity plus D7-branes describing the addition of an arbitrary number of flavors to the Klebanov-Tseytlin and Klebanov-Strassler backgrounds. We provide a precise field theory dual and a detailed analysis of the duality cascade which describes its RG flow. Matchings of beta functions and anomalies between the field theory and the string setup are presented. We give an understanding of Seiberg duality as a large gauge transformation on the RR and NSNS potentials. We also analyze the UV behavior of the field theory, that as su…
The non-perturbative properties of the gauge theories in the AdS${}_4$ are studied in the dual supergravity by including light flavor quarks, which are introduced by a D7 brane embedding. Contrary to the cases of Minkowski and dS${}_4$, the dilaton does not play any important dynamical role in the AdS${}_4$ case, and the characteristic properties like the quark confinement and the chiral symmetry breaking are realized mainly due to the geometry AdS${}_4$. The possible hadron spectra %in the AdS${}_4$ are also examined, and we find that the meson spectra are well described by the formula given …
In the context of AdS/CFT, we consider a cascading theory with an arbitrarily large number of chiral flavors. In the UV the theory can be considered as a chiral flavoring of the Klebanov-Tseytlin solution, and exhibits a duality wall. Instead in the IR, due to the rich dynamics, it safely flows to a non-cascading theory. We engineer the field theory through intersecting D7-branes with world-volume gauge flux on a conifold with 3-form fluxes, and we find new fully backreacted solutions of Type IIB Supergravity plus branes. We match the field theory cascade with supergravity by computing Page ch…
In the context of AdS/CFT with flavor, we consider the type IIB supergravity solution corresponding to a fully localized D3/D7 intersection. We complete the standard metric ansatz by providing an analytic expression for the warp factor, under the assumption of a logarithmically running axion-dilaton. From the gauge dual perspective, this behavior is related to the positive beta function of the N=4, d=4 SU(N_c) super Yang-Mills gauge theory, coupled to N_f fundamental N=2 hypermultiplets. We comment on the existence of tadpoles and relate them to the same gauge theory beta function. Next we con…
We consider the addition of a large number of massive dynamical flavors to the Klebanov-Witten theory, the quiver gauge theory describing the low energy dynamics of Nc D3-branes at the conifold singularity. Massive flavors are introduced by means of Nf D7-branes which are holomorphically embedded and smeared along the transverse directions. After some general comments on the validity of the smearing procedure, we find the full backreacted supergravity solution corresponding to a particular class of massive embeddings. The solution depends on a running effective number of flavors, whose functio…
Based on the gauge-gravity duality, we study the three-dimensional QCD ($\mathrm{QCD}_{3}$) and Chern-Simons theory by constructing the anisotropic black D3-brane solution in IIB supergravity. The deformed bulk geometry is obtained by performing a double Wick rotation and dimension reduction which becomes an anisotropic bubble configuration exhibiting confinement in the dual theory. And its anisotropy also reduces to a Chern-Simons term due to the presence of the dissolved D7-branes or the axion field in bulk. Using the bubble geometry, we investigate the the ground-state energy density, quark…
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…
This paper is concerned with an extension of the well known Kaluza-Klein mechanism. As the standard ansatz for Kaluza-Klein reduction implies the existence of a gauge potential associated with the KK field strength, it follows immediately that this field strength satisfies its Bianchi identity. Hence, the standard KK formalism breaks down in the presence of a violated Bianchi identity. This occurs for example in the context of D6 sources. We will investigate and partially solve this problem in the context of the type IIA/M-theory duality. Our discussion is motivated by the construction of gaug…
Dynamical properties of gauge theories with light flavor quarks are studied in a dual supergravity by adding a D7-brane probe into the AdS background deformed by the dilaton. By estimating the vev of flavor quark-bilinear in both the supersymmetric and non-supersymmetric gravity duals, we find spontaneous chiral symmetry breaking in the case of the non-supersymmetric background. We also study quark-antiquark potential for light quarks to see the quark confinement in the models considered here.
In conventional supergravity theories, supersymmetry is broken by a non-zero F-term, and the cosmological constant is fine tuned to zero by a constant in the superpotential W. We discuss a class of supergravity theories with vanishing F-terms but $W \not= 0$ being generated dynamically. The cosmological constant is assumed to be cancelled by a non-zero D-term. In this scenario the gravity-mediated soft masses depend only on a single parameter, the gravitino mass. They are automatically universal, independently of the Kahler metric, and real. Thus, dangerous flavor or CP violating interactions …
We study the addition of flavor degrees of freedom to the supergravity dual of the non-commutative deformation of the maximally supersymmetric gauge theories. By considering D7 flavor branes in the probe approximation and studying their fluctuations we extract the spectrum of scalar and vector mesons as a function of the non-commutativity. We find that the spectrum for very large non-commutative parameter is equal to the one in the commutative theory, while for some intermediate values of the non-commutativity some of the modes disappear from the discrete spectrum. We also study the semiclassi…
