We formulate a supersymmetric theory in which both a dilaton and a second-rank tensor play roles of compensators. The basic off-shell multiplets are a linear multiplet (B_{μν}, χ, ϕ) and a vector multiplet (A_μ, ł; C_{μνρ}), where ϕand B_{\m\n} are respectively a dilaton and a second-rank tensor. The third-rank tensor C_{μνρ} in the vector multiplet is 'dual' to the conventional D-field with 0 on-shell or 1 off-shell degree of freedom. The dilaton ϕis absorbed into one longitudinal component of A_μ, making it massive. Initially, B_{μν} has 1 on-shell or 3 off-shell degrees of freedom, but it is absorbed into the longitudinal components of C_{μνρ}. Eventually, C_{μνρ} with 0 on-shell or 1 off-shell degree of freedom acquires in total 1 on-shell or 4 off-shell degrees of freedom, turning into a propagating massive field. These basic multiplets are also coupled to chiral multiplets and a supersymmetric Dirac-Born-Infeld action. Some of these results are also reformulated in superspace. The proposed mechanism may well provide a solution to the long-standing puzzle of massless dilatons and second-rank tensors in supersymmetric models inspired by string theory.
We present a variant formulation of N=1 supersymmetric compensator mechanism for an arbitrary non-Abelian group in four dimensions. This formulation resembles our previous variant supersymmetric compensator mechanism in 4D. Our field content consists of the three multiplets: (i) A Non-Abelian Yang-Mills multiplet (A_μ^I, λ^I, C_{μνρ}^I), (ii) a tensor multiplet (B_{μν}^I, χ^I, φ^I) and an extra vector multiplet (K_μ^I, ρ^I, C_{μνρ}^I) with the index I for the adjoint representation of a non-Abelian gauge group. The C_{μνρ}^I is originally an auxiliary field dual to the conventional auxiliary f…
The action for 2d dilatonic supergravity with dilaton coupled matter and dilaton multiplets is constructed. Trace anomaly and anomaly induced effective action (in components as well as in supersymmetric form) for matter supermultiplet on bosonic background are found. The one-loop effective action and large-$N$ effective action for quantum dilatonic supergravity are also calculated. Using induced effective action one can estimate the back-reaction of dilaton coupled matter to the classical black hole solutions of dilatonic supergravity. That is done on the example of supersymmetric CGHS model w…
The supersymmetric generalization of dilatations in the presence of the dilaton is defined. This is done by defining the supersymmetric dilaton geometry which is motivated by the supersymmetric volume preserving diffeomorphisms. The resulting model is classical superconformal field theory with an additional dilaton-axion supermultiplet coupled to the supersymmetric gauge theory, where the dilaton-axion couplings are nonrenormalizable. The possibility of spontaneous scale symmetry breaking is investigated in this context. There are three different types of vacua with broken scale symmetry depen…
We present a new (variant) formulation of N=1 supersymmetric compensator mechanism for an arbitrary non-Abelian group in four dimensions. We call this `variant supersymmetric non-Abelian Proca-Stueckelberg formalism'. Our field content is economical, consisting only of the two multiplets: (i) A Non-Abelian vector multiplet (A_μ^I, λ^I, C_{μνρ}{}^I) and (ii) A compensator tensor multiplet (B_{μν}{}^I, χ^I, φ^I). The index I is for the adjoint representation of a non-Abelian gauge group. The C_{μνρ}{}^I is originally an auxiliary field Hodge-dual to the conventional auxiliary field D^I. The φ^I …
Using the superspace formalism, we compute for the two-dimensional N=1 supersymmetric non-linear $σ$-model, the order $(α^{\prime})^{2}$ $(R_{mnpq})^2$ (three-loop) correction to the central charge via the operator product expansion of the supercurrent with itself. The contribution vanishes, in agreement with previous results obtained from the usual $σ$-model $β$-function approach.
We show that there is a non-trivial relationship between the dilaton of IIB supergravity, and the coset of scalar fields in five-dimensional, gauged N=8 supergravity. This has important consequences for the running of the gauge coupling in massive perturbations of the AdS/CFT correspondence. We conjecture an exact analytic expression for the ten-dimensional dilaton in terms of five-dimensional quantities, and we test this conjecture. Specifically, we construct a family of solutions to IIB supergravity that preserve half of the supersymmetries, and are lifts of supersymmetric flows in five-dime…
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.
A method for quantizing the bidimensional N=2 supersymmetric non-linear sigma model is developed. This method is both covariant under coordinate transformations (concerning the order relevant for calculations) and explicitly N=2 supersymmetric. The OPE of the supercurrent is computed accordingly, including also the dilaton. By imposing the N=2 superconformal algebra the equations for the metric and dilaton are obtained. In particular, they imply that the dilaton is a constant.
We propose the supersymmetric extension of the modified Born-Infeld-axion-dilaton non-linear electrodynamics that has confined static abelian solutions used for describing the electromagnetic confinement in the presence of axion and dilaton fields, and charged matter. The supersymmetric extension also has the non-trivial scalar potential that implies the upper bounds on the matter fields.
Meson spectra given as fluctuations of a D7 brane are studied under the background driven by the dilaton. This leads to a dual gauge theory with quark confinement due to the gauge condensate. We find that the effect of the gauge condensate on the meson spectrum is essential in order to make a realistic hadron spectrum in the non-supersymmetric case. In the supersymmetric case, however, only the spectra of the scalars are affected, but they are changed in an opposite way compared to the non-supersymmetric case.
We analyze the backreaction of dilaton tadpoles on the geometry of non-supersymmetric strings. After finding explicit warped solutions for a T-dual version of the Sugimoto model, we examine the possibility of realizing large extra dimension scenarios within the context of non-supersymmetric string models. Our analysis reveals an appealing mechanism to dynamically reduce the number of flat, non-compact directions in non-supersymmetric string theories.
We study several classes of marginal deformations of the conformal field theory SU(2) x R. This theory describes the near-horizon region of a stack of parallel and coincident NS5-branes and is related holographically to little string theory. We investigate the supersymmetry properties of these deformations and we elucidate their role in the context of holography. The conformal field theory moduli space contains "non-holographic" operators that do not seem to have a simple interpretation in little string theory. Subsequently, we analyze several NS5-brane configurations in terms of SU(2) x R def…
We investigate unattractor behavior in non-extremal black holes in Einstein-Born-Infeld-Dilaton theory of gravity in four-dimensional asymptotically flat spacetime. We obtain solutions which are non-singular near the horizon and dependent on the value of the dilaton field at the infinity, using perturbation method. It is shown that the value of the scalar field at the horizon is determined by its asymptotic value and the charges carried by the black hole. And we also find it is not true in general that the dilaton value at the horizon is a monotonically increasing function of the first coeffic…
We analyze a supergravity theory coupled to a dilaton and superconformal matters in two dimensions. This theory is classically soluble and we find all the solutions appeared in Callan, Giddings, Harvey and Strominger's dilatonic gravity also satisfy the constraints and the equations of motion in this supersymmetric theory. We quantize this theory by following the procedure of Distler, Hlousek and Kawai. In the quantum action, the cosmological term is renormalized to vanish. As a result, any solution corresponding to classical black hole does not appear in the quantum theory, which should be co…
We briefly review the covariant formulation of the Green-Schwarz superstring by Berkovits, and describe how a detailed tree-level and one-loop analysis of this model leads, for the first time, to a derivation of the low-energy effective action of the heterotic superstring while keeping target-space supersymmetry manifest. The resulting low-energy theory is old-minimal supergravity coupled to tensor multiplet. The dilaton is part of the compensator multiplet.
Supersymmetric bulk-brane coupling in Horava-Witten and Randall-Sundrum scenarios, when considered in the orbifold (``upstairs'') picture, enjoys similar features: a modified Bianchi identity and a modified supersymmetry transformation for the ``orthogonal'' part of the gauge field. Using a toy model with a 5D vector multiplet in the bulk (like in Mirabelli-Peskin model, but with an \emph{odd} gauge field $A_m$), we explain how these features arise from the superfield formulation. We also show that the corresponding construction in the boundary (``downstairs'') picture requires introduction of…
We study glueballs in the holographic gauge theories, supersymmetric and non-super symmetric cases, which are given by the type IIB superstring solutions with non-trivial dilaton. In both cases, the dilaton reflects the condensate of the gauge field strength, $<F^2>$, which is responsible to the linear confining potential between the quark and anti-quark. Then we could see the meson spectra. On the other hand, the glueball spectra are not found in the supersymmetric case. We need a sharp wall, which corresponds to an infrared cutoff, in order to obtain the glueballs. In the non-supersymmetric …
By extending the recent analysis of arXiv:2203.12203 for ${\mathcal{N}}=2$ conformal supergravity in four dimensions, we define new hyper-dilaton Weyl multiplets for five-dimensional ${\mathcal{N}}=1$, and six-dimensional ${\mathcal{N}}=(1,0)$ conformal supergravities. These are constructed by coupling the five- and six-dimensional standard Weyl multiplets to on-shell hypermultiplets and reinterpreting the systems as new multiplets of conformal supergravity. In the five-dimensional case, we also construct a new hyper-dilaton Poincaré supergravity by coupling to an off-shell vector multiplet co…
We study the quantum cosmology of the 2D Hawking-Page massless scalar-field model and the homogeneous and isotropic dilation-axion string cosmology.For both models we find new exact solutions for the Wheeler-DeWitt equation and for the supersymmetric wave function equations. We show that the Wheeler-DeWitt equations for the Hawking-Page model and the axion-dilaton string cosmology are invariant under a one-parameter and two-parameter squeezed transformations, respectively. These results allow to find new solutions for the wave functions of these systems at the quantum cosmology level. Also, we…
We couple a recently-established N=1 globally supersymmetric self-dual Yang-Mills multiplet in three dimensions to supergravity. This becomes possible due to our previous result on globally supersymmetric formulation based on a compensator multiplet. We further couple the self-dual vector to a supersymmetric sigma-model on the coset SO(8,n) / SO(8) X SO(n) via minimal couplings for an arbitrary gauged subgroup H_0 \subset SO(8) X SO(n). A corresponding superspace formulation is also presented.
We present a systematic discussion of supersymmetric solutions of 2D dilaton supergravity. In particular those solutions which retain at least half of the supersymmetries are ground states with respect to the bosonic Casimir function (essentially the ADM mass). Nevertheless, by tuning the prepotential appropriately, black hole solutions may emerge with an arbitrary number of Killing horizons. The absence of dilatino and gravitino hair is proven. Moreover, the impossibility of supersymmetric dS ground states and of nonextremal black holes is confirmed, even in the presence of a dilaton. In thes…
The supersymmetric action of type IIA D=10 superstring in N=2a, D=10 supergravity background can be derived by double dimensional reduction of the action of supermembrane coupled to D=11 supergravity. We demonstrate that the background Ramond-Ramond fields appear in the resulting superstring action with an extra factor of exponential of the dilaton.
In this paper we reconsider the derivation of anomaly mediated supersymmetry breaking. We work in a general formalism where the F-term of the conformal compensator superfield is arbitrary. This allows for a continuous interpolation between the original derivation and a more recent Dine-Seiberg derivation of anomaly mediation. We show that the physical soft parameters are independent of the compensator F-term and results of two formalisms agree. Finally, we discuss the role of supersymmetric and non-supersymmetric thresholds in the effective low energy Lagrangian as well as the effects of expli…
Non-conformal supercurrents in six dimensions are described, which contain the trace of the energy-momentum tensor and the gamma-trace of the supersymmetry current amongst their component fields. Within the superconformal approach to ${\cal N} = (1, 0)$ supergravity, we present various distinct non-conformal supercurrents, one of which is associated with an ${\cal O}(2)$ (or linear) multiplet compensator, while another with a tensor multiplet compensator. We also derive an infinite class of non-conformal supercurrents involving ${\cal O}(n)$ multiplets with $n > 2$. As an illustrative example …
The field equations for both generic bosonic and generic locally supersymmetric 2D dilatonic gravity theories in the absence of matter are written as free differential algebras. This constitutes a generalization of the gauge theoretic formulation. Moreover, it is shown that the condition of free differential algebra can be used to obtain the equations in the locally supersymmetric case. Using this formulation, the general solution of the field equations is found in the language of differential forms. The relation with the ordinary formulation and the coupling to supersymmetric conformal matter…
An $N = 1$ supersymmetric version of two dimensional dilaton gravity coupled to matter is considered. It is shown that the linear dilaton vacuum spontaneously breaks half the supersymmetries, leaving broken a linear combination of left and right supersymmetries which squares to time translations. Supersymmetry suggests a spinorial expression for the ADM energy $M$, as found by Witten in four-dimensional general relativity. Using this expression it is proven that ${M}$ is non-negative for smooth initial data asymptotic (in both directions) to the linear dilaton vacuum, provided that the (not ne…
We discuss R-symmetry in locally supersymmetric $N=2$ gauge theories coupled to hypermultiplets, which can be viewed as effective theories of heterotic string models. In this type of supergravities a suitable R-symmetry exists and can be used to topologically twist the theory. The vector multiplet of the dilaton-axion field has a different R-charge assignment with respect to the other vector multiplets.
We present the theory describing supersymmetrical vortices in the curved superspace of the (1,0) supergravity. The action is defined as a (1,0) locally supersymmetric $SU(2)/U(1)$ coset perturbed by the cosmological constant-like term. The perturbation is such that it preserves the integrability of the coset model. Because of supersymmetry the perturbed theory is an exact quantum system provided a proper dilaton is taken into account. The exact value of the dilaton is determined in the supersymmetric case by the quasi-classical background of the bosonic coset.
The reduced field equations and BPS conditions are derived in Type IIB supergravity for configurations of the Janus type, characterized by an $AdS_4$-slicing of $AdS_5$, and various degrees of internal symmetry and supersymmetry. A generalization of the Janus solution, which includes a varying axion along with a varying dilaton, and has SO(6) internal symmetry, but completely broken supersymmetry, is obtained analytically in terms of elliptic functions. A supersymmetric solution with 4 conformal supersymmetries, SU(3) internal symmetry, a varying axion along with a varying dilaton, and non-tri…
Global geometry of $K3$-fibration Calabi-Yau threefolds, with Hodge number $h_{2,1}=r+1$, is used to define $N=4$ softly broken $SU(r+1)$ gauge theories, with the bare coupling constant given by the dual heterotic dilaton, and the mass of the adjoint hypermultiplet given by the heterotic string tension. The $U(r+1)$ Donagi-Witten integrable model is also derived from the $K3$-fibration structure, with the extra $U(1)$ associated to the heterotic dilaton. The case of $SU(2)$ gauge group is analyzed in detail. String physics beyond the heterotic point particle limit is partially described by the…
We develop a formalism to construct supersymmetric backgrounds within the superspace formulation for five-dimensional (5D) conformal supergravity given in arXiv:0802.3953. Our approach is applicable to any off-shell formulation for 5D minimal Poincare and anti-de Sitter supergravity theories realized as the Weyl multiplet coupled with two compensators. For those superspace backgrounds which obey the equations of motion for (gauged) supergravity, we naturally reproduce the supersymmetric solutions constructed a decade ago by Gauntlett et al. For certain supersymmetric backgrounds with eight sup…
In supersymmetric theories the mass of any state is bounded below by the values of some of its charges. The corresponding bounds in case of Schwarzschild and Reissner-Nordström black holes are known to coincide with the requirement that naked singularities be absent. Here we investigate charged dilaton black holes in this context. We show that the extreme solutions saturate the supersymmetry bound of $N=4\ d=4$ supergravity, or dimensionally reduced superstring theory. Specifically, we have shown that extreme dilaton black holes, with electric and magnetic charges, admit super-covariantly cons…
We briefly discuss the differences between considering the gauge coupling as a constant or as a field, the dilaton, in N=1 supersymmetric theories. We emphasize the differences regarding supersymmetry breaking. Recent developments on the nonperturbative dynamics of these theories provide new ideas on the induced dilaton potential and its stabilization.
A new class of non-compact Kahler backgrounds accompanied by a non-constant dilaton field is constructed as a supergravity solution. It is interpreted as a complex line bundle over a base manifold comprising of a combination of arbitrary coset spaces, and also includes the case of Calabi-Yau manifolds. The resulting backgrounds have U(1) isometry. We consider N=2 supersymmetric sigma-models on them, and derive a non-Kahlerian solution by U(1) duality transformation, which preserves N=2 supersymmetry.
We investigate the low energy properties of string vacua with spontaneously broken $N=1$ supersymmetry by a dilaton $F$-term. As a consequence of the universal couplings of the dilaton, the supersymmetric mass spectrum is determined in terms of only three independent parameters and more constrained than in the minimal supersymmetric Standard Model. For a $μ$-term induced by the \K\ potential the parameter space becomes two-dimensional; in the allowed regions of this parameter space we find that most supersymmetric particles are determined solely by the gluino mass. The Higgs is rather light an…
We define a new dilaton Weyl multiplet of ${\mathcal{N}}=2$ conformal supergravity in four dimensions. This is constructed by reinterpreting the equations of motion of an on-shell hypermultiplet as constraints that render some of the fields of the standard Weyl multiplet composite. The independent bosonic components include four scalar fields and a triplet of gauge two-forms. The resulting, so-called, hyper-dilaton Weyl multiplet defines a $24+24$ off-shell representation of the local ${\mathcal{N}}=2$ superconformal algebra. By coupling the hyper-dilaton Weyl multiplet to an off-shell vector …
We present a new set of supersymmetric stationary solutions of pure N=4,d=4 supergravity (and, hence, of low-energy effective string theory) that generalize (and include) the Israel-Wilson-Perjés solutions of Einstein-Maxwell theory. All solutions have 1/4 of the supersymmetries unbroken and some have 1/2. The full solution is determined by two arbitrary complex harmonic functions {\cal H}_{1,2} which transform as a doublet under SL(2,\R) S duality and N complex constants k^{(n)} that transform as an SO(N) vector. This set of solutions is, then, manifestly duality invariant. When the harmonic …
The N=1 supersymmetric version of generalized 2d dilaton gravity can be cast into the form of a Poisson Sigma Model, where the target space and its Poisson bracket are graded. The target space consists of a 1+1 superspace and the dilaton, which is the generator of Lorentz boosts therein. The Poisson bracket on the target space induces the invariance of the worldsheet theory against both diffeomorphisms and local supersymmetry transformations (superdiffeomorphisms). The machinery of Poisson Sigma Models is then used to find the general local solution to the field equations. As a byproduct, clas…
The superspace formulation for four-dimensional N = 2 matter-coupled supergravity recently developed in arXiv:0805.4683 makes use of a new type of conformal compensator with infinitely many off-shell degrees of freedom: the so-called covariant weight-one polar hypermultiplet. In the present note we prove the duality of this formulation to the known minimal (40+40) off-shell realization for N = 2 Poincare supergravity involving the improved tensor compensator. Within the latter formulation, we present new off-shell matter couplings realized in terms of covariant weight-zero polar hypermultiplet…
We show that there exist supersymmetric Minkowski vacua on Type IIB toroidal orientifold with general flux compactifications where the RR tadpole cancellation conditions can be relaxed and the Freed-Witten anomaly can be cancelled elegantly. We present a realistic Pati-Salam like flux model without the Freed-Witten anomaly. At the string scale, we can break the gauge symmetry down to the Standard Model (SM) gauge symmetry, achieve the gauge coupling unification naturally, and decouple all the extra chiral exotic particles. Thus, we have the supersymmetric SMs with/without SM singlet(s) below t…
We describe the supersymmetric completion of several curvature-squared invariants for ${\cal N}=(1,0)$ supergravity in six dimensions. The construction of the invariants is based on a close interplay between superconformal tensor calculus and recently developed superspace techniques to study general off-shell supergravity-matter couplings. In the case of minimal off-shell Poincaré supergravity based on the dilaton-Weyl multiplet coupled to a linear multiplet as a conformal compensator, we describe off-shell supersymmetric completions for all the three possible purely gravitational curvature-sq…
Recent understanding of {\cal N}=1* supersymmetric theory (mass deformed {\cal N}=4) has made it possible to find an exact superpotential which encodes the properties of the different phases of the theory. We consider this superpotential as an illustrative example for the source of a nontrivial scalar potential for the string theory dilaton and study its properties. The superpotential is characterized by the rank of the corresponding gauge group (N) and integers p,q,k labelling the different massive phases of the theory. For generic values of these parameters, we find the expected runaway beha…
Six-dimensional (1,0) supersymmetric gauged Einstein-Maxwell supergravity is extended by the inclusion of a supersymmetric Riemann tensor squared invariant. Both the original model as well as the Riemann tensor squared invariant are formulated off-shell and consequently the total action is off-shell invariant without modification of the supersymmetry transformation rules. In this formulation, superconformal techniques, in which the dilaton Weyl multiplet plays a crucial role, are used. It is found that the gauging of the U(1) R-symmetry in the presence of the higher-order derivative terms does…
We investigate the dependence of the gauge couplings on the dilaton field in string effective theories at the one--loop level. First we resolve the discrepancies between statements based on symmetry considerations and explicit calculations in string effective theories on this subject. A calculation of the relevant one--loop scattering amplitudes in string theory gives us further information and allows us to derive the exact form of the corresponding effective Lagrangian. In particular there is no dilaton dependent one--loop correction to the holomorphic $f$--function arising from massive strin…
We present an N=1 supersymmetric non-Abelian compensator formulation for a vector multiplet in three-dimensions. Our total field content is the off-shell vector multiplet (A_μ^I, λ^I) with the off-shell scalar multiplet (ϕ^I, χ^I; F^I) both in the adjoint representation of an arbitrary non-Abelian gauge group. This system is reduced to a supersymmetric sigma-model on a group manifold, in the zero-coupling limit. Based on this result, we formulate a 'self-dual' non-Abelian vector multiplet in three-dimensions. By an appropriate identification of parameters, the mass of the self-dual vector mult…
We consider $2d$ sigma models with a $D=2+N$ - dimensional Minkowski signature target space metric having a covariantly constant null Killing vector. These models are UV finite. The $2+N$-dimensional target space metric can be explicitly determined for a class of supersymmetric sigma models with $N$-dimensional `transverse' part of the target space being homogeneous Kähler. The corresponding `transverse' sub-theory is an $n=2$ supersymmetric sigma model with the exact $\gb$-function coinciding with its one-loop expression. For example, the finite $D=4$ model has $O(3)$ supersymmetric sigma mod…
Supersymmetric Peccei-Quinn symmetry and string theory predict a complex scalar field comprising a dilaton and an axion. These fields are massless at high energies, but it is known since long that the axion is stabilized in an instanton dominated vacuum. Instantons and axions together also provide a mechanism to stabilize a dilaton, thus accounting for a dilaton as a possible cold dark matter component accompanying the axion. We briefly review the prospects of this scenario and point out further implications.
We show that $N=8$ {\it self-dual} supergravity theory, which is the consistent background for $N=2$ closed superstring theory in $2+2\-$dimensions, can accommodate the recently discovered two-dimensional dilaton gravity black hole solution, {\it via} appropriate dimensional reductions and truncations. Interestingly, the usual dilaton field in this set of solutions emerges from the scalar field in the ${\bf 70}\-$dimensional representation of an intrinsic global $SO(8)$ group. We also give a set of exact solutions, which can be interpreted as the dilaton field on Eguchi-Hanson gravitational in…
We examine duality transformations of supersymmetric and $κ$-symmetric Dp-brane actions in a general type II supergravity background where in particular the dilaton and the axion are supposed to not be zero or a constant but a general superfield. Due to non-constant dilaton and axion, we can explicitly show that the dilaton and the axion as well as the two 2-form gauge potentials transform as doublets under the $SL(2,R)$ transformation from the point of view of the world-volume field theory.
We carry out the N=1 supersymmetrization of a physical non-Abelian tensor with non-trivial consistent couplings in four dimensions. Our system has three multiplets: (i) The usual non-Abelian vector multiplet (VM) (A_μ^I, λ^I), (ii) A non-Abelian tensor multiplet (TM) (B_{μν}{}^I, χ^I, φ^I), and (iii) A compensator vector multiplet (CVM) (C_μ^I, ρ^I). All of these multiplets are in the adjoint representation of a non-Abelian group G. Unlike topological theory, all of our fields are propagating with kinetic terms. The C_μ^I-field plays the role of a Stueckelberg compensator absorbed into the lon…
We present plane-wave-type solutions of the lowest order superstring effective action which have unbroken space-time supersymmetries. They describe dilaton, axion and gauge fields in a stringy generalization of the Brinkmann metric. Some conspiracy between the metric and the axion field is required. We show that there exists a special class of these solutions, for which $α^\prime$ stringy corrections to the effective on-shell action, to the equations of motion (and therefore to the solutions themselves), and to the supersymmetry transformations vanish. We call these solutions supersymmetric st…
We investigate the attractor mechanism for spherically symmetric extremal black holes in Einstein-Born-Infeld-dilaton theory of gravity in four-dimensions, in the presence of a cosmological constant. We look for solutions analytic near the horizon by using perturbation method. It is shown that the values of the scalar fields at the horizon are only dependent on the charges carried by the black hole and are irrelevant in their asymptotic values. This analysis supports the validity of non-supersymmetric attractors in the presence of higher derivative interactions in the gauge fields part and in …
We study dilaton stabilization in heterotic string models. By utilizing the asymmetric orbifold construction, we construct an explicit three-generation model whose matter content in the visible sector is the supersymmetric standard model with additional vectorlike matter. This model does not contain any geometric moduli fields except the dilaton field. Model building at a symmetry enhancement point in moduli space enlarges the rank of the hidden gauge group. By analyzing multiple hidden gauge sectors, the dilaton field is stabilized by the racetrack mechanism. We also discuss a supersymmetry b…
We construct the half-supersymmetric instanton solutions that are electric-magnetically dual to the recently discussed half-supersymmetric Q7-branes. We call these instantons `Q-instantons'. Whereas the D-instanton is most conveniently described using the RR axion χand the dilaton ϕ, the Q-instanton is most conveniently described using a different set of fields χ' and T, where χ' is an axionic scalar. The real part of the Q-instanton on-shell action is a function of T and the imaginary part is linear in χ'. Discrete shifts of the axion χ' correspond to PSL(2,Z) transformations that are of fini…
In this letter we discuss the relation of four-dimensional, $N=2$ supersymmetric string backgrounds to integrable models. In particular we show that non-Kählerian gravitational backgrounds with one $U(1)$ isometry plus non-trivial antisymmetric tensor and dilaton fields arise as the solutions of the Liouville equation or, for the case of vanishing central charge deficit, as the solutions of the continual Toda equation. When performing an Abelian duality transformation, a particular class of solutions of the continual Toda equation leads to the well-known gravitational Eguchi-Hanson instanton b…
We explicitly construct the supersymmetry transformations for the N=2 supersymmetric RG flow solution of chiral IIB supergravity. We show that the metric, dilaton/axion, five-index tensor and half of the three index tensor are determined algebraically in terms of the Killing spinor of the unbroken supersymmetry. The algebraic nature of the solution allows us to generalize this construction to a new class of N=2 supersymmetric solutions of IIB supergravity. Each solution in this class is algebraically determined by supersymmetry and is parametrized by a single function of two variables that sat…
A new approach is provided to determine the dilaton--antisymmetric tensor coupling in a supergravity theory by considering the static supersymmetric field configuration around a super extended object, which is consistently formulated in a curved superspace. By this, the corresponding SUSY transformation rules can also be determined for vanishing fermionic fields as well as bosonic fields other than those in the determined coupling. Therefore, we can, in turn, use this determined part of the supergravity theory to study all the related vacuum-like solutions. We have determined the dilaton--anti…
We show that the `instantonic' soliton of five-dimensional Yang-Mills theory and the closely related BPS monopole of four-dimensional Yang-Mills/Higgs theory continue to be exact static, and stable, solutions of these field theories even after the inclusion of gravitational, electromagnetic and, in the four-dimensional case, dilatonic interactions, provided that certain non-minimal interactions are included. With the inclusion of these interactions, which would be required by supersymmetry, these exact self-gravitating solitons saturate a gravitational version of the Bogomol'nyi bound on the e…
We classify $\mathcal N = 2$ Minkowski$_4$ solutions of IIB supergravity with an $SU(2)_R$ symmetry geometrically realized by an $S^2$-foliation in the remaining six dimensions. For the various cases of the classification, we reduce the supersymmetric system of equations to PDEs. These cases often accommodate systems of intersecting branes and half-maximally supersymmetric AdS$_{5,6,7}$ solutions when they exist. As an example, we analyze the AdS$_6$ case in more detail, reducing the supersymmetry equations to a single cylindrical Laplace equation. We also recover an already known linear dilat…
