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Sep 24, 2013
09/13

by
Johanna Erdmenger

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A quantum-field theoretical interpretation is given to the holographic RG equation by relating it to a field-theoretical local RG equation which determines how Weyl invariance is broken in a quantized field theory. Using this approach we determine the relation between the holographic C theorem and the C theorem in two-dimensional quantum field theory which relies on the Zamolodchikov metric. Similarly we discuss how in four dimensions the holographic C function is related to a conjectured...

Source: http://arxiv.org/abs/hep-th/0103219v2

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Sep 21, 2013
09/13

by
Johanna Erdmenger

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We construct the three point function involving an axial vector current and two energy-momentum tensors for four dimensional conformal field theories. Conformal symmetry determines the form of this three point function uniquely up to a constant factor if the necessary conservation conditions are imposed. The gravitational axial anomaly present on a curved space background leads to a non-zero contribution for the divergence of the axial current in this three point function even on flat space....

Source: http://arxiv.org/abs/hep-th/9905176v2

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Sep 18, 2013
09/13

by
Johanna Erdmenger; Christian Rupp

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Superconformal Ward identities for N=1 supersymmetric quantum field theories in four dimensions are convenienty obtained in the superfield formalism by combining diffeomorphisms and Weyl transformations on curved superspace. Using this approach we study the superconformal transformation properties of Green functions with one or more insertions of the supercurrent to all orders in perturbation theory. For the case of two insertions we pay particular attention to fixing the additional...

Source: http://arxiv.org/abs/hep-th/9811209v2

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Sep 22, 2013
09/13

by
Johanna Erdmenger; Stephan Steinfurt

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We holographically compute supercharge diffusion constants in supersymmetric field theories, dual to AdS black brane solutions of arbitrary dimension. This includes the extension of earlier work by Kontoudi and Policastro for D3-branes to M2- and M5-brane theories. We consider the case of vanishing chemical potential. In particular, we relate the product of a diffusion constant and the energy density to a universal result for the fermionic absorption cross section. This relation is analogous to...

Source: http://arxiv.org/abs/1302.1869v2

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Sep 23, 2013
09/13

by
Johanna Erdmenger; Veselin Filev

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In the context of gauge/gravity duality, we study both probe D7-- and probe D5--branes in global Anti-de Sitter space. The dual field theory is N=4 theory on R x S^3 with added flavour. The branes undergo a geometrical phase transition in this geometry as function of the bare quark mass m_q in units of 1/R with R the S^3 radius. The meson spectra are obtained from fluctuations of the brane probes. First, we study them numerically for finite quark mass through the phase transition. Moreover, at...

Source: http://arxiv.org/abs/1012.0496v2

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Sep 20, 2013
09/13

by
Nicolas Boulanger; Johanna Erdmenger

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Following a purely algebraic procedure, we provide an exhaustive classification of local Weyl-invariant scalar densities in dimension D=8.

Source: http://arxiv.org/abs/hep-th/0405228v2

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Sep 23, 2013
09/13

by
Johanna Erdmenger; Ingo Kirsch

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In view of extending gauge/gravity dualities with flavour beyond the probe approximation, we establish the gravity dual description of mesons for a three-dimensional super Yang-Mills theory with fundamental matter. For this purpose we consider the fully backreacted D2/D6 brane solution of Cherkis and Hashimoto in an approximation due to Pelc and Siebelink. The low-energy field theory is the IR fixed point theory of three-dimensional N=4 SU(N_c) super Yang-Mills with N_f fundamental fields,...

Source: http://arxiv.org/abs/hep-th/0408113v2

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Sep 18, 2013
09/13

by
Gordon Chalmers; Johanna Erdmenger

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We examine the dual correspondence between holographic IIB superstring theory and N=4 super Yang-Mills theory at finite values of the coupling constants. In particular we analyze a field theory strong-coupling expansion which is the S-dual of the planar expansion. This expansion arises naturally as the AdS/CFT dual of the IIB superstring scattering amplitudes given a genus truncation property due to modular invariance. The space-time structure of the contributions to the field theory four-point...

Source: http://arxiv.org/abs/hep-th/0005192v1

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Sep 18, 2013
09/13

by
Johanna Erdmenger; Christian Rupp

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We determine the structure of geometrical superconformal anomalies for N=1 supersymmetric quantum field theories on curved superspace to all orders in h bar. For the massless Wess-Zumino model we show how these anomalies contribute to the local Callan-Symanzik equation which expresses the breakdown of superconformal symmetry in terms of the usual beta and gamma functions.

Source: http://arxiv.org/abs/hep-th/9809090v1

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Sep 20, 2013
09/13

by
Johanna Erdmenger; Shu Lin

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We consider a gauge/gravity dual model of thermalization which consists of a collapsing thin matter shell in asymptotically Anti-de Sitter space. A central aspect of our model is to consider a shell moving at finite velocity as determined by its equation of motion, rather than a quasi-static approximation as considered previously in the literature. By applying a divergence matching method, we obtain the evolution of singularities in the retarded unequal time correlator $G^R(t,t')$, which probes...

Source: http://arxiv.org/abs/1205.6873v1

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Sep 18, 2013
09/13

by
James Babington; Johanna Erdmenger

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We consider N=1 supersymmetric gauge theories in which the couplings are allowed to be space-time dependent functions. Both the gauge and the superpotential couplings become chiral superfields. As has recently been shown, a new topological anomaly appears in models with space-time dependent gauge coupling. Here we show how this anomaly may be used to derive the NSVZ beta function in a particular, well-determined renormalisation scheme, both without and with chiral matter. Moreover we extend the...

Source: http://arxiv.org/abs/hep-th/0502214v1

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Sep 21, 2013
09/13

by
Johanna Erdmenger; Matthias Kaminski; Felix Rust

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In this talk we present applications of the AdS/CFT correspondence to strongly coupled systems at finite temperature and particle density. The model we investigate contains adjoint matter described by the gauge multiplet of N=4, as well as fundamental matter given by the hypermultiplet of N=2 Super Yang-Mills theory. In some aspects these systems can be thought of as models for the quark-gluon plasma. In the first part we review some properties of meson spectra obtained from these holographic...

Source: http://arxiv.org/abs/0901.2456v1

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Jun 30, 2018
06/18

by
Souvik Banerjee; Johanna Erdmenger; Debajyoti Sarkar

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In the context of relating AdS/CFT to quantum information theory, we propose a holographic dual of Fisher information metric for mixed states in the boundary field theory. This amounts to a holographic measure for the distance between two mixed quantum states. For a spherical subregion in the boundary we show that this is related to a particularly regularized volume enclosed by the Ryu-Takayanagi surface. We further argue that the quantum correction to the proposed Fisher information metric is...

Topics: High Energy Physics - Theory, General Relativity and Quantum Cosmology, Quantum Physics

Source: http://arxiv.org/abs/1701.02319

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Sep 20, 2013
09/13

by
Oren Bergman; Johanna Erdmenger; Gilad Lifschytz

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Gauge/gravity duality is a useful and efficient tool for addressing and studying questions related to strongly interacting systems described by a gauge theory. In this manuscript we will review a number of interesting phenomena that occur in such systems when a background magnetic field is turned on. Specifically, we will discuss holographic models for systems that include matter fields in the fundamental representation of the gauge group, which are incorporated by adding probe branes into the...

Source: http://arxiv.org/abs/1207.5953v2

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Sep 21, 2013
09/13

by
Johanna Erdmenger; Zachary Guralnik; Ingo Kirsch

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We study four-dimensional superconformal field theories coupled to three-dimensional superconformal boundary or defect degrees of freedom. Starting with bulk N=2, d=4 theories, we construct abelian models preserving N=2, d=3 supersymmetry and the conformal symmetries under which the boundary/defect is invariant. We write the action, including the bulk terms, in N=2, d=3 superspace. Moreover we derive Callan-Symanzik equations for these models using their superconformal transformation properties...

Source: http://arxiv.org/abs/hep-th/0203020v2

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Sep 23, 2013
09/13

by
Johanna Erdmenger; Patrick Kerner; Hansjörg Zeller

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We study transport phenomena in p-wave superfluids in the context of gauge/gravity duality. Due to the spacetime anisotropy of this system, the tensorial structure of the transport coefficients is non-trivial in contrast to the isotropic case. In particular, there is an additional shear mode which leads to a non-universal value of the shear viscosity even in an Einstein gravity setup. In this paper, we present a complete study of the helicity two and helicity one fluctuation modes. In addition...

Source: http://arxiv.org/abs/1110.0007v2

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Sep 23, 2013
09/13

by
Johanna Erdmenger; Daniel Fernandez; Hansjörg Zeller

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We complete the analysis of transport phenomena in p-wave superfluids within gauge/gravity duality, using the SU(2) Einstein-Yang-Mills model with backreaction. In particular, we analyze the fluctuation modes of helicity zero in addition to the helicity one and two modes studied earlier. We compute a further transport coefficient, associated to the first normal stress difference, not previously considered in the holographic context. In the unbroken phase this is related to a minimally coupled...

Source: http://arxiv.org/abs/1212.4838v2

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Sep 23, 2013
09/13

by
Johanna Erdmenger; Matthias Kaminski; Felix Rust

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We consider gauge/gravity duality with flavor for the finite-temperature field theory dual of the AdS-Schwarzschild black hole background with embedded D7-brane probes. In particular, we investigate spectral functions at finite baryon density in the black hole phase. We determine the resonance frequencies corresponding to meson-mass peaks as function of the quark mass over temperature ratio. We find that these frequencies have a minimum for a finite value of the quark mass. If the quotient of...

Source: http://arxiv.org/abs/0710.0334v3

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Sep 19, 2013
09/13

by
Johanna Erdmenger; Christian Rupp; Klaus Sibold

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We investigate the superconformal transformation properties of Green functions with one or more insertions of the supercurrent in N=1 supersymmetric quantum field theories. These Green functions are conveniently obtained by coupling the supercurrent and its trace to a classical supergravity background. We derive flat space superconformal Ward identities from diffeomorphisms and Weyl transformations on curved superspace. For the classification of potential quantum superconformal anomalies in the...

Source: http://arxiv.org/abs/hep-th/9804053v2

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Sep 21, 2013
09/13

by
Johanna Erdmenger; Kazuo Ghoroku; Ingo Kirsch

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In the context of gauge/gravity duals with flavor, we examine heavy-light mesons which involve a heavy and a light quark. For this purpose we embed two D7 brane probes at different positions into the gravity background. We establish the non-Abelian Dirac-Born-Infeld (DBI) action for these probes, in which the U(2) matrix describing the embedding is diagonal. The fluctuations of the brane probes correspond to the mesons. In particular, the off-diagonal elements of the U(2) fluctuation matrix...

Source: http://arxiv.org/abs/0706.3978v2

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54

Sep 18, 2013
09/13

by
Johanna Erdmenger; Matthias Kaminski; Felix Rust

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We study the gauge/gravity dual of a finite temperature field theory at finite isospin chemical potential by considering a probe of two coincident D7-branes embedded in the AdS-Schwarzschild black hole background. The isospin chemical potential is obtained by giving a vev to the time component of the non-Abelian gauge field on the brane. The fluctuations of the non-Abelian gauge field on the brane are dual to the SU(2) flavor current in the field theory. For the embedding corresponding to...

Source: http://arxiv.org/abs/0704.1290v2

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Sep 21, 2013
09/13

by
Johanna Erdmenger; Patrick Kerner; Hansjörg Zeller

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A very famous result of gauge/gravity duality is the universality of the ratio of shear viscosity to entropy density in every field theory holographically dual to classical, two-derivative (Einstein) gravity. We present a way to obtain deviation form this universality by breaking the rotational symmetry spontaneously. In anisotropic fluids additional shear modes exist and their corresponding shear viscosities may be non-universal. We confirm this by explicitly calculating the shear viscosities...

Source: http://arxiv.org/abs/1011.5912v2

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Jun 30, 2018
06/18

by
Johanna Erdmenger; Nick Evans; Marc Scott

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Using holography, we study the low-lying mesonic spectrum of a range of asymptotically free gauge theories. First we revisit a simple top-down holographic model of QCD-like dynamics with predictions in the M_rho-M_pi plane. The meson masses in this model are in very good agreement with lattice gauge theory calculations in the quenched approximation. We show that the key ingredient for the meson mass predictions is the running of the anomalous dimension of the quark condensate, gamma. This...

Topics: High Energy Physics - Theory, High Energy Physics - Phenomenology, High Energy Physics - Lattice

Source: http://arxiv.org/abs/1412.3165

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Jun 30, 2018
06/18

by
Johanna Erdmenger; Mario Flory; Charlotte Sleight

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We study the extremal surfaces of functionals recently proposed for the holographic calculation of entanglement entropy in general higher curvature theories, using New Massive gravity and Gauss-Bonnet gravity as concrete examples. We show that the entropy functionals admit closed extremal surfaces, which for black hole backgrounds can encircle the event horizon of the black hole. In the examples considered, such closed surfaces correspond to a lower value of the entropy functional than expected...

Topics: High Energy Physics - Theory, General Relativity and Quantum Cosmology

Source: http://arxiv.org/abs/1401.5075

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Sep 18, 2013
09/13

by
Riccardo Apreda; Johanna Erdmenger; Nick Evans

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We consider D7 brane probes embedded in deformed AdS5 x S5 supergravity backgrounds which are non-supersymmetric in the interior. In the context of the generalised AdS/CFT correspondence, these setups are dual to QCD-like theories with fundamental matter which display chiral symmetry breaking by a quark condensate. Evaluating the D7 action for a surface instanton configuration gives rise to an effective potential for the scalar Higgs vev in the dual field theory. We calculate this potential for...

Source: http://arxiv.org/abs/hep-th/0509219v3

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Sep 24, 2013
09/13

by
Johanna Erdmenger; Carlos Hoyos; Shu Lin

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Within AdS/CFT, we establish a general procedure for obtaining the leading singularity of two-point correlators involving operator insertions at different times. The procedure obtained is applied to operators dual to a scalar field which satisfies Dirichlet boundary conditions on an arbitrary time-like surface in the bulk. We determine how the Dirichlet boundary conditions influence the singularity structure of the field theory correlation functions. New singularities appear at boundary points...

Source: http://arxiv.org/abs/1112.1963v2

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Sep 18, 2013
09/13

by
Johanna Erdmenger; Nick Evans; Johannes Grosse

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We propose a holographic description of heavy-light mesons, i.e. of mesons containing a light and a heavy quark. In the semi-classical string limit, we look at the dynamics of strings tied between two D7 branes. We consider this setup both in an AdS background and in the non-supersymmetric Constable-Myers geometry which induces chiral symmetry breaking. We compute the meson masses in each case. Finally we discuss the relevance of this result for phenomenological comparison to the physical...

Source: http://arxiv.org/abs/hep-th/0605241v3

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Sep 23, 2013
09/13

by
Johanna Erdmenger; Kazuo Ghoroku; Rene Meyer

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For type IIB supergravity with a running axio-dilaton, we construct bulk solutions which admit a cosmological background metric of Friedmann-Robertson-Walker type. These solutions include both a dark radiation term in the bulk as well as a four-dimensional (boundary) cosmological constant, while gravity at the boundary remains non-dynamical. We holographically calculate the stress-energy tensor, showing that it consists of two contributions: The first one, generated by the dark radiation term,...

Source: http://arxiv.org/abs/1105.1776v2

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Sep 18, 2013
09/13

by
Johanna Erdmenger; Rene Meyer; Jeong-Hyuck Park

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Using a novel, string theory-inspired formalism based on a Hamiltonian constraint, we obtain a conformal mechanical system for the spatially flat four-dimensional Robertson-Walker Universe. Depending on parameter choices, this system describes either a relativistic particle in the Robertson-Walker background, or metric fluctuations of the Robertson-Walker geometry. Moreover we derive a tree-level M-theory matrix model in this time-dependent background. Imposing the Hamiltonian constraint forces...

Source: http://arxiv.org/abs/0705.1586v1

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Sep 21, 2013
09/13

by
Johanna Erdmenger; Rene Meyer; Jonathan P. Shock

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We investigate gauge/gravity duals with flavour for which pure-gauge Kalb-Ramond B fields are turned on in the background, into which a D7 brane probe is embedded. First we consider the case of a magnetic field in two of the spatial boundary directions. We show that at finite temperature, i.e. in the AdS-Schwarzschild background, the B field has a stabilizing effect on the mesons and chiral symmetry breaking occurs for a sufficiently large value of the B field. Then we turn to the electric case...

Source: http://arxiv.org/abs/0709.1551v3

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Sep 22, 2013
09/13

by
Johanna Erdmenger; Shu Lin; Thanh Hai Ngo

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It is expected that thermalization may be described within gauge/gravity duality by considering time-dependent configurations on the gravity side of the correspondence, for instance a gravitational collapse of a matter configuration in Anti-de Sitter space. As a step towards the ambitious goal of describing such a configuration, we investigate a simple time-dependent toy model in which a mirror moves in the radial direction of Anti-de Sitter space. For this configuration, we establish a...

Source: http://arxiv.org/abs/1101.5505v2

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Sep 24, 2013
09/13

by
Johanna Erdmenger; Veselin G. Filev; Dimitrios Zoakos

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Within gauge/gravity duality, we construct a backreacted supergravity background dual to SU(Nc) N=4 SYM coupled to Nf massive fundamental flavours in the presence of an external magnetic field. Our solution is perturbative in a parameter that counts the number of the internal flavour loops. The background has a hollow cavity in the bulk of the geometry, where it is similar to the supergravity dual of a non-commutative SYM. The radius of this cavity is related to the dynamically generated mass...

Source: http://arxiv.org/abs/1112.4807v1

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Jun 30, 2018
06/18

by
Johanna Erdmenger; Mario Flory; Max-Niklas Newrzella

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We consider a holographic dual model for defect conformal field theories (DCFT) in which we include the backreaction of the defect on the dual geometry. In particular, we consider a dual gravity system in which a two-dimensional hypersurface with matter fields, the brane, is embedded into a three-dimensional asymptotically Anti-de Sitter spacetime. Motivated by recent proposals for holographic duals of boundary conformal field theories (BCFT), we assume the geometry of the brane to be...

Topics: High Energy Physics - Theory, Strongly Correlated Electrons, General Relativity and Quantum...

Source: http://arxiv.org/abs/1410.7811

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Sep 22, 2013
09/13

by
Johanna Erdmenger; Jeong-Hyuck Park; Corneliu Sochichiu

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For a generic two-dimensional 0A string background, we map the Dirac-Born-Infeld action to a matrix model. This is achieved using a canonical transformation. The action describes D0-branes in this background, while the matrix model has a potential which encodes all the information of the background geometry. We apply this formalism to specific backgrounds: For Rindler space, we obtain a matrix model with an upside-down quadratic potential, while for AdS_2 space, the potential is linear....

Source: http://arxiv.org/abs/hep-th/0603243v3

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Jun 30, 2018
06/18

by
Johanna Erdmenger; Mukund Rangamani; Stephan Steinfurt; Hansjörg Zeller

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We present the long-wavelength effective description of non-extremal spinning black D3-branes in flat space. Our setup is motivated by recent explorations of low energy dynamics on black brane world-volumes within the blackfold approach and its connections to the fluid/gravity correspondence. The spinning D3-branes with a rigid radial Dirichlet cut-off give rise to an effective field theory. This theory describes a charged plasma which is driven by external forces, given by one vector and two...

Topics: High Energy Physics - Theory, General Relativity and Quantum Cosmology

Source: http://arxiv.org/abs/1412.0020

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Jun 29, 2018
06/18

by
Johanna Erdmenger; Daniel Fernandez; Prieslei Goulart; Piotr Witkowski

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In the context of applications of the AdS/CFT correspondence to condensed matter physics, we compute conductivities for field theory duals of dyonic planar black holes in 3+1-dimensional Einstein-Maxwell-dilaton theories at zero temperature. We combine the near-horizon data obtained via Sen's entropy function formalism with known expressions for conductivities. In this way we express the conductivities in terms of the extremal black hole charges. We apply our approach to three different...

Topic: High Energy Physics - Theory

Source: http://arxiv.org/abs/1611.09381

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Sep 19, 2013
09/13

by
Riccardo Apreda; Johanna Erdmenger; Dieter Lust; Christoph Sieg

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As an extension of holography with flavour, we analyze in detail the embedding of a D7-brane probe into the Polchinski-Strassler gravity background, in which the breaking of conformal symmetry is induced by a 3-form flux G_3. This corresponds to giving masses to the adjoint chiral multiplets. We consider the N=2 supersymmetric case in which one of the adjoint chiral multiplets is kept massless while the masses of the other two are equal. This setup requires a generalization of the known...

Source: http://arxiv.org/abs/hep-th/0610276v1

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Sep 21, 2013
09/13

by
Martin Ammon; Johanna Erdmenger; Patrick Kerner; Migael Strydom

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In the context of gauge/gravity duality, we find a new black hole instability in asymptotically AdS spaces. On the field theory side, this instability is induced by a magnetic field in the vacuum, in contrast to previous instabilities which occur at finite density. On the gravity side, this corresponds to a spatial component of the gauge field in SU(2) Einstein-Yang-Mills theory, which provides the crucial non-Abelian structure. Our analysis may provide supporting evidence for recent QCD...

Source: http://arxiv.org/abs/1106.4551v2

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Jun 30, 2018
06/18

by
Xavier Bekaert; Johanna Erdmenger; Dmitry Ponomarev; Charlotte Sleight

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Within holography, we calculate the contribution of an arbitrary spin-s gauge boson exchange in $AdS_{d+1}$ to the four-point function with scalar operators on the boundary. As an important ingredient, we first compute the complete bulk-to-bulk propagators for massless bosonic higher-spin fields in the metric-like formulation, in any dimension and in various gauges. The split representation of the bulk-to-bulk propagators in terms of bulk-to-boundary propagators allows to present the...

Topic: High Energy Physics - Theory

Source: http://arxiv.org/abs/1412.0016

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Sep 23, 2013
09/13

by
Martin Ammon; Johanna Erdmenger; Matthias Kaminski; Patrick Kerner

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We give a detailed account and extensions of a holographic flavor superconductivity model which we have proposed recently. The model has an explicit field theory realization as strongly coupled N=2 Super Yang-Mills theory with fundamental matter at finite temperature and finite isospin chemical potential. Using gauge/gravity duality, i.e. a probe of two flavor D7-branes in the AdS black hole background, we show that the system undergoes a second order phase transition with critical exponent...

Source: http://arxiv.org/abs/0903.1864v2

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Sep 19, 2013
09/13

by
Riccardo Apreda; Johanna Erdmenger; Dieter Lust; Christoph Sieg

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We motivate and summarize our analysis of hep-th/0610276 in which we consider D7-brane probe embeddings in the Polchinski-Strassler background with N=2 supersymmetry. The corresponding dual gauge theory is given by the N=2* theory with fundamental matter.

Source: http://arxiv.org/abs/hep-th/0701246v1

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Jun 28, 2018
06/18

by
Xavier Bekaert; Johanna Erdmenger; Dmitry Ponomarev; Charlotte Sleight

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Clarifying the locality properties of higher-spin gravity is a pressing task, but notoriously difficult due to the absence of a weakly-coupled flat regime. The simplest non-trivial case where this question can be addressed is the quartic self-interaction of the AdS scalar field present in the higher-spin multiplet. We investigate this issue in the context of the holographic duality between the minimal bosonic higher-spin theory on AdS$_4$ and the free $O\left(N\right)$ vector model in three...

Topic: High Energy Physics - Theory

Source: http://arxiv.org/abs/1508.04292

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Sep 20, 2013
09/13

by
Johanna Erdmenger; Kazuo Ghoroku; Rene Meyer; Ioannis Papadimitriou

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We review a construction of holographic geometries dual to N=4 SYM theory on a Friedmann-Robertson-Walker background and in the presence or absence of a gluon condensate and instanton density. We find the most general solution with arbitrary scale factor and show that it is diffeomorphic to topological black holes. We introduce a time-dependent boundary cosmological constant \lambda(t) and show energy-momentum conservation in this background. For constant \lambda, the deconfinement properties...

Source: http://arxiv.org/abs/1205.0677v1

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Sep 17, 2013
09/13

by
Johanna Erdmenger; Nick Evans; Ingo Kirsch; Ed Threlfall

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We review recent progress in studying mesons within gauge/gravity duality, in the context of adding flavour degrees of freedom to generalizations of the AdS/CFT correspondence. Our main focus is on the `top-down approach' of considering models constructed within string theory. We explain the string-theoretical constructions in detail, aiming at non-specialists. These give rise to a new way of describing strongly coupled confining large N gauge gauge theories similar to large N QCD. In...

Source: http://arxiv.org/abs/0711.4467v2

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Sep 18, 2013
09/13

by
Stefan Antusch; Koushik Dutta; Johanna Erdmenger; Sebastian Halter

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Recently, a class of inflation models in supergravity with gauge non-singlet matter fields as the inflaton has been proposed. It is based on a `tribrid' structure in the superpotential and on a Heisenberg symmetry for solving the eta-problem. We suggest that a generalization of this model class may be suitable for realising inflation in heterotic orbifold compactifications, where the Heisenberg symmetry is a property of the tree-level K"ahler potential of untwisted matter fields. We...

Source: http://arxiv.org/abs/1102.0093v1

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81

Sep 17, 2013
09/13

by
Martin Ammon; Johanna Erdmenger; Matthias Kaminski; Andy O'Bannon

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We use gauge-gravity duality to compute spectral functions of fermionic operators in a strongly-coupled defect field theory in p-wave superfluid states. The field theory is (3+1)-dimensional N=4 supersymmetric SU(Nc) Yang-Mills theory, in the 't Hooft limit and with large coupling, coupled to two massless flavors of (2+1)-dimensional N=4 supersymmetric matter. We show that a sufficiently large chemical potential for a U(1) subgroup of the global SU(2) isospin symmetry triggers a phase...

Source: http://arxiv.org/abs/1003.1134v2

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Jun 29, 2018
06/18

by
Xavier Bekaert; Johanna Erdmenger; Dmitry Ponomarev; Charlotte Sleight

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We present arguments which suggest that the bulk higher-spin gravity duals of weakly-coupled conformal field theories obey some refined notion of locality. In particular, we discuss the Mellin amplitude programme in this context. We focus on the $O(N)$ vector model and minimal higher-spin gravity as a paradigmatic example of such holographic dual pairs. We restrict ourselves to three- and four-point functions of scalar primary operators, but the qualitative conclusions are expected to hold for...

Topic: High Energy Physics - Theory

Source: http://arxiv.org/abs/1602.08570

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42

Sep 23, 2013
09/13

by
Martin Ammon; Johanna Erdmenger; Matthias Kaminski; Patrick Kerner

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We consider thermal strongly-coupled N=2 SYM theory with fundamental matter at finite isospin chemical potential. Using gauge/gravity duality, i.e. a probe of two flavor D7-branes embedded in the AdS black hole background, we find a critical temperature at which the system undergoes a second order phase transition. The critical exponent of this transition is one half and coincides with the result from mean field theory. In the thermodynamically favored phase, a flavor current acquires a vev and...

Source: http://arxiv.org/abs/0810.2316v2

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41

Sep 22, 2013
09/13

by
Johanna Erdmenger; Zachary Guralnik; Robert Helling; Ingo Kirsch

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We study brane recombination for supersymmetric configurations of intersecting branes in terms of the world-volume field theory. This field theory contains an impurity, corresponding to the degrees of freedom localized at the intersection. The Higgs branch, on which the impurity fields condense, consists of vacua for which the intersection is deformed into a smooth calibrated manifold. We show this explicitly using a superspace formalism for which the calibration equations arise naturally from...

Source: http://arxiv.org/abs/hep-th/0309043v2

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40

Sep 22, 2013
09/13

by
Johanna Erdmenger; Sebastian Halter; Carlos Nunez; Gianmassimo Tasinato

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We propose a new model of slow-roll inflation in string cosmology, based on warped throat supergravity solutions displaying `walking' dynamics, i.e. the coupling constant of the dual gauge theory slowly varies over a range of energy scales. The features of the throat geometry are sourced by a rich field content, given by the dilaton and RR and NS fluxes. By considering the motion of a D3-brane probe in this geometry, we are able to analytically calculate the brane potential in a physically...

Source: http://arxiv.org/abs/1210.4179v2