arXiv subjects

A. A. Tseytlin

Publications and source records attributed to A. A. Tseytlin.

At least 163 records · Page 9Linked to original sources

arXiv2000

Superparticle and superstring in AdS_3 x S^3 Ramond-Ramond background in light-cone gauge

We discuss superparticle and superstring dynamics in AdS_3 x S^3 supported by R-R 3-form background using light-cone gauge approach. Starting with the superalgebra psu(1,1|2) + psu(1,1|2) representing the basic symmetry of this background we find the light-cone superparticle Hamiltonian. We determine the harmonic decomposition of light-cone superfield describing fluctuations of type IIB supergravity fields expanded near AdS_3 x S^3 background and compute the corresponding Kaluza-Klein spectrum. We fix the fermionic and bosonic light-cone gauges in the covariant Green-Schwarz AdS_3 x S^3 superstring action and find the light-cone string Hamiltonian. We also obtain a realization of the generators of psu(1,1|2) + psu(1,1|2) in terms of the superstring 2-d fields in the light-cone gauge.

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arXiv2000

Light-cone Superstring in AdS Space-time

We consider fixing the bosonic light-cone gauge for string in AdS in the phase space framework, i.e. by choosing $x^+ = τ$, and by choosing $σ$ so that $P^+$ is distributed uniformly (its density is independent of $σ$). We discuss classical bosonic string in AdS space and superstring in AdS_5 x S^5. In the latter case the starting point is the action found in hep-th/0007036 where the kappa-symmetry is fixed by a fermionic light cone gauge. We derive the light cone Hamiltonian in the AdS_5 x S^5 case and in the case of superstring in AdS_3 x S^3. We also obtain a realization of the generators of the basic symmetry superalgebra psu(2,2|4) in terms of the AdS_5 x S^5 superstring coordinate fields.

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arXiv2000

Superstrings in AdS in light cone gauge

We discuss light-cone gauge description of type IIB Green-Schwarz superstring in AdS_5 x S^5 with a hope to make progress towards understanding spectrum of this theory. As in flat space, fixing light cone gauge consists of two steps: (i) fixing kappa symmetry in such a way that the fermionic part of the action does not depend on x^-; (ii) fixing 2-d reparametrizations by x^+ = tau and a condition on 2-d metric. In curved AdS space the latter cannot be the standard conformal gauge and breaks manifest 2-d Lorentz invariance. It is natural, therefore, to work in phase-space framework, imposing the GGRT gauge conditions x^+= tau, P^+ =const. We obtain the resulting light cone superstring Hamiltonian. This is a review of hep-th/0007036 and hep-th/0009171.

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arXiv2000

Conformal Sigma Models for a Class of $T^{p,q}$ Spaces

We consider a 2-d conformal theory based on (G x G')/ H coset sigma model introduced by Guadagnini, Martellini and Mintchev. It is shown that in the case of {SU(2) x SU(2)}/ U(1) the metric of the corresponding background is of T^{p,q} coset space form (but is not an Einstein one). Similar interpretation is possible for the Lorentzian coset space W_{4,2}= {SL(2,R) x SL(2,R)}/U(1). The resulting 10-d homogeneous space metric on W_{4,2} x T^{p,q} supplemented with 2-form field gives a critical NS-NS superstring background with conformal sigma model interpretation.

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arXiv2000

Long quantum superstrings in AdS_5 x S^5

Following hep-th/0001204 we discuss the computation of quantum corrections near long IIB superstring configurations in AdS_5 x S^5 which are related to the Wilson loop expectation values in the strong coupling expansion of the dual n=4 SYM theory with large N. We use the Green-Schwarz description of superstrings in curved R-R backgrounds and demonstrate that it is well-defined and useful for developing perturbation theory near long string backgrounds.

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arXiv2000

Curved branes from string dualities

We describe a simple method for generating new string solutions for which the brane worldvolume is a curved space. As a starting point we use solutions with NS-NS charges combined with 2-d CFT's representing different parts of space-time. We illustrate our method with many examples, some of which are associated with conformally invariant sigma models. Using U-duality, we also obtain supergravity solutions with RR charges which can be interpreted as D-branes with non-trivial worldvolume geometry. In particular, we discuss the case of a D5-brane wrapped on AdS_3 x S^3, a solution interpolating between AdS_3 x S^3 x R^5 and AdS_3 x S^3 x S^3 x R, and a D3-brane wrapped over S^3 x R or AdS_2 x S^2. Another class of solutions we discuss involves NS5-branes intersecting over a 3-space and NS5-branes intersecting over a line. These solutions are similar to D7-brane or cosmic string backgrounds.

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arXiv2000

Gravity Duals of Supersymmetric SU(N) x SU(N+M) Gauge Theories

The world volume theory on N regular and M fractional D3-branes at the conifold singularity is a non-conformal n=1 supersymmetric SU(N+M) x SU(N) gauge theory. In previous work the Type IIB supergravity dual of this theory was constructed to leading non-trivial order in M/N: it is the AdS_5 x T^{1,1} background with NS-NS and R-R 2-form fields turned on. Far in the UV this dual description was shown to reproduce the logarithmic flow of couplings found in the field theory. In this paper we study the supersymmetric RG flow at all scales. We introduce an ansatz for the 10-d metric and other fields and show that the equations of motion may be derived in first order form from a simple superpotential. This allows us to explicitly solve for the gravity dual of the RG trajectory.

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arXiv2000

Conformal anomaly of (2,0) tensor multiplet in six dimensions and AdS/CFT correspondence

We compute the conformal anomaly of free d=6 superconformal (2,0) tensor multiplet on generic curved background. Up to a trivial covariant total-derivative term, it is given by the sum of the type A part proportional to the 6-d Euler density, and the type B part containing three independent Weyl invariants. Multiplied by factor 4N^3, the type B part of the anomaly reproduces exactly the corresponding part of the conformal anomaly of large N multiple M5-brane (2,0) theory as predicted (hep-th/9806087) by the AdS/CFT correspondence. The coefficients of the type A anomaly differ by the factor 4/7 x 4 N^3, so that the free tensor multiplet anomaly does not vanish on a Ricci-flat background. The coefficient 4N^3 is the same as found (hep-th/9703040) in the comparison of the tensor multiplet theory and the d=11 supergravity results for the absorption cross-sections of gravitons by M5 branes, and in the comparison (hep-th/9911135) of 2- and 3-point stress tensor correlators of the free tensor multiplet with the AdS_7 supergravity predictions. The reason for this coincidence is that the three Weyl-invariant terms in the anomaly are related to the $h^2$ and $h^3$ terms in the near flat space expansion of the corresponding non-local effective action, and thus to the 2-point and 3-point stress tensor correlators in flat background. At the same time, the type A anomaly is related to the $h^4$ term in the non-local part of the effective action, i.e. to a certain structure in the 4-point correlation function of stress tensors.

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arXiv1999

Magnetic Interactions of D-branes and Wess-Zumino Terms in Super Yang-Mills Effective Actions

There is a close relation between classical supergravity and quantum SYM descriptions of interactions between separated branes. In the case of D3 branes, the equivalence of leading-order potentials is due to non-renormalization of the F^4 term in N=4 SYM theory. Here we point out the existence of another special non-renormalized term in quantum SYM effective action. This term reproduces the interaction potential between electric charge of a D3-brane probe and magnetic charge of a D3-brane source, represented by the Chern-Simons part of the D-brane action. This unique Wess-Zumino term depends on all six scalar fields and originates from a phase of the euclidean fermion determinant in SYM theory. It is manifestly scale invariant (i.e. is the same for large and small separations between branes) and can not receive higher loop corrections in gauge theory. Maximally supersymmetric SYM theories in D=p+1>4 contain mixed WZ terms which depend on both scalar and gauge field backgrounds, and which reproduce the corresponding CS terms in the supergravity interaction potentials between separated Dp-branes for p>3. Purely scalar WZ terms appear in other cases, e.g., in N=2 gauge theories in various dimensions describing magnetic interactions between Dp and D(6-p) branes.

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arXiv1999

Three-point correlators of stress tensors in maximally-supersymmetric conformal theories in d=3 and d=6

We consider free superconformal theories of n=8 scalar multiplet in d=3 and (2,0) tensor multiplet in d=6 and compute 2-point and 3-point correlators of their stress tensors. The results for the 2-point and 3-point correlators for a single d=3 and d=6 multiplet differ from the "strong-coupling" AdS_4 and AdS_7 supergravity predictions by the factors $4\sqrt2 \over 3π}N^{3/2}$ and $4N^3$ respectively. These are the same factors as found earlier in hep-th/9703040 in the comparison of the brane free field theory and the 11-d supergravity predictions for the absorption cross-sections of longitudinally polarized gravitons by multiple M2 and M5 branes. While the correspondence of the results for the cross-sections and 2-point functions was expected on the basis of unitarity, the fact that the same coefficients appear in the ratio of the free-theory and supergravity 3-point functions is non-trivial. Thus, like in the d=4 SYM case, in both d=3 and d=6 theories the ratio of the 3-point and 2-point correlators / is exactly the same in the free field theory and in the interacting CFT as described (to leading order in large $N$) by the 11-d supergravity on AdS_{d+1} x S^{10-d}.

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arXiv1999

Born-Infeld action, supersymmetry and string theory

We review and elaborate on some aspects of Born-Infeld action and its supersymmetric generalizations in connection with string theory. Contents: BI action from string theory; some properties of bosonic D=4 BI action; N=1 and N=2 supersymmetric BI actions with manifest linear D=4 supersymmetry; four-derivative terms in N=4 supersymmetric BI action; BI actions with `deformed' supersymmetry from D-brane actions; non-abelian generalization of BI action; derivative corrections to BI action in open superstring theory.

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arXiv1999

On Low-Energy Effective Actions in N = 2, 4 Superconformal Theories in Four Dimensions

We study some aspects of low-energy effective actions in 4-d superconformal gauge theories on the Coulomb branch. We describe superconformal invariants constructed in terms of N=2 abelian vector multiplet which play the role of building blocks for the N=2,4 supersymmetric low-energy effective actions. We compute the one-loop effective actions in constant N=2 field strength background in N=4 SYM theory and in N=2 SU(2) SYM theory with four hypermultiplets in fundamental representation. Using the classification of superconformal invariants we then find the manifestly N=2 superconformal form of these effective actions. While our explicit computations are done in the one-loop approximation, our conclusions about the structure of the effective actions in N=2 superconformal theories are general. We comment on some applications to supergravity - gauge theory duality in the description of D-brane interactions.

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arXiv1999

Dilaton - fixed scalar correlators and AdS_5 x S^5 - SYM correspondence

We address the question of AdS/CFT correspondence in the case of the 3-point function . O_4 and O_8 are particular primary states represented by F^2 + ... and F^4 + ... operators in \N=4 SYM theory and dilaton ϕand massive `fixed' scalar νin D=5 supergravity. While the value of computed in large N weakly coupled SYM theory is non-vanishing, the D=5 action of type IIB supergravity compactified on S^5 does not contain ϕϕνcoupling and thus the corresponding correlator seems to vanish on the AdS_5 side. This is in obvious contradiction with arguments suggesting non-renormalization of 2- and 3-point functions of states from short multiplets and implying agreement between the supergravity and SYM expressions for them. We propose a natural resolution of this paradox which emphasizes the 10-dimensional nature of the correspondence. The basic idea is to treat the constant mode of the dilaton as a part of the full S^5 Kaluza-Klein family of dilaton modes. This leads to a non-zero result for the correlator on the supergravity side.

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arXiv1999

A Non-supersymmetric Large N CFT from Type 0 String Theory

We show that type 0B theory has a classical AdS_5 x S^5 solution and argue that it is stable at the string-theory level for small enough radius. The dual 4-d conformal field theory is the infrared limit of the theory on N electric D3-branes coincident with N magnetic D3-branes. We explicitly construct this SU(N) x SU(N) gauge theory with global SO(6) symmetry and verify that the one-loop term in the beta function vanishes exactly, while the two-loop term vanishes in the large N limit. We find that this theory is related by a certain projection to the maximally supersymmetric Yang-Mills theory suggesting its large N conformal invariance to all orders in perturbation theory.

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arXiv1999

D3-brane - D-instanton configuration and N=4 super YM theory in constant self-dual background

We consider SO(4) x SO(6) invariant type IIB string solution describing D3-branes superposed with D-instantons homogeneously distributed over D3-brane world-volume. In the near D3-brane horizon limit this background interpolates between AdS_5 x S^5 space in UV and flat space (with non-constant dilaton and RR scalar) in IR. Generalizing the AdS/CFT conjecture we suggest that type IIB string in this geometry is dual to N=4 SYM theory in a state with a constant self-dual gauge field background. The semiclassical string representation for the Wilson factor implies confinement with effective string tension depending on constant D-instanton density parameter. This provides a simple example of type IIB string -- gauge theory duality with clear D-brane and gauge theory interpretation.

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arXiv1999

Effective potential in non-supersymmetric SU(N) x SU(N) gauge theory and interactions of type 0 D3-branes

We study some aspects of short-distance interaction between parallel D3-branes in type 0 string theory as described by the corresponding world-volume gauge theory. We compute the one-loop effective potential in the non-supersymmetric SU(N) x SU(N) gauge theory (which is a Z_2 projection of the U(2N) n=4 SYM theory) representing dyonic branes composed of N electric and N magnetic D3-branes. The branes of the same type repel at short distances, but an electric and a magnetic brane attract, and the forces between self-dual branes cancel. The self-dual configuration (with the positions of the electric and the magnetic branes, i.e. the diagonal entries of the adjoint scalar fields, being the same) is stable against separation of one electric or one magnetic brane, but is unstable against certain modes of separation of several same-type branes. This instability should be suppressed in the large N limit, i.e. should be irrelevant for the large N CFT interpretation of the gauge theory suggested in hep-th/9901101.

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arXiv1999

D-Branes and Dual Gauge Theories in Type 0 String Theory

We consider the type 0 theories, obtained from the closed NSR string by a diagonal GSO projection which excludes space-time fermions, and study the D-branes into these theories. The low-energy dynamics of N coincident D-branes is governed by a U(N) gauge theory coupled to adjoint scalar fields. It is tempting to look for the type 0 string duals of such bosonic gauge theories in the background of the R-R charged p-brane classical solutions. This results in a picture analogous to the one recently proposed by Polyakov (hep-th/9809057). One of the serious problems that needs to be resolved is the closed string tachyon mode which couples to the D-branes and appears to cause an instability. We study the tachyon terms in the type 0 effective action and argue that the background R-R flux provides a positive shift of the (mass)^2 of the tachyon. Thus, for sufficiently large flux, the tachyonic instability may be cured, removing the most basic obstacle to constructing the type 0 duals of non-supersymmetric gauge theories. We further find that the tachyon acquires an expectation value in presence of the R-R flux. This effect is crucial for breaking the conformal invariance in the dual description of the 3+1 dimensional non-supersymmetric gauge theory.

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arXiv1998

Free energy of N=4 super Yang-Mills in Higgs phase and non-extremal D3-brane interactions

We study the free energy of \N=4 super Yang-Mills theory in the Higgs phase with a mass scale M corresponding to non-zero v.e.v. of the scalar fields. At zero temperature this theory describes a system of parallel separated extremal D3-branes. Non-zero temperature corresponds to non-extremality in supergravity description. We interpret the supergravity interaction potential between a non-extremal D3-brane and a D3-brane probe as contribution of massive states to the free energy of N --> infinity SYM theory at strong 't Hooft coupling (N g^2_{YM} >> 1). Both low (M >> T) and high (T >> M) temperature regimes are considered. For low temperature we find that the structure of terms that appear in the free energy at strong and weak coupling is the same. The analysis of the high-temperature regime depends on a careful identification of the scalar field v.e.v. in terms of the distance between branes in the supergravity description and again predicts strong coupling terms similar to those found in the weak-coupling \N=4 SYM theory. We consider also the corrections to the strong coupling results by taking into account the leading \a'^3 R^4 string contribution to the supergravity effective action. This gives rise to the (N g^2_{YM})^{-3/2} corrections in the coefficient functions of 't Hooft coupling which multiply different terms in free energy.

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