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715
Brane/Flux Annihilation and the String Dual of a NonSupersymmetric Field Theory
, 2006
"... We consider the dynamics of p antiD3 branes inside the KlebanovStrassler geometry, the deformed conifold with M units of RR 3form flux around the S 3. We find that for p << M the system relaxes to a nonsupersymmetric NS 5brane “giant graviton ” configuration, which is classically stable, b ..."
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Cited by 170 (18 self)
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We consider the dynamics of p antiD3 branes inside the KlebanovStrassler geometry, the deformed conifold with M units of RR 3form flux around the S 3. We find that for p << M the system relaxes to a nonsupersymmetric NS 5brane “giant graviton ” configuration, which is classically stable, but quantum mechanically can tunnel to a nearby supersymmetric vacuum with M −p D3 branes. This decay mode is exponentially suppressed and proceeds via the nucleation of an NS 5brane bubble wall. We propose a dual field theory interpretation of the decay as the transition between a nonsupersymmetric “baryonic” branch and a supersymmetric “mesonic” branch of the corresponding SU(2M − p) × SU(M − p) low energy gauge theory. The NS 5brane tunneling process also provides a simple visualization of the The search for calculable and nontrivial nonsupersymmetric string vacua remains a problem of basic interest in string theory. In the context of AdS/CFT duality [1], this is related to the construction of gravitational “antiholographic” descriptions for nonsupersymmetric 4d quantum gauge theories. Here, we describe the construction of a simple nonsupersymmetric
Scalar speed limits and cosmology: Acceleration from D cceleration
 Phys. Rev. D70 (2004) 103505, hepth/0310221
"... Causality on the gravity side of the AdS/CFT correspondence restricts motion on the moduli space of the N = 4 super Yang Mills theory by imposing a speed limit on how fast the scalar field may roll. This effect can be traced to higher derivative operators arising from integrating out light degrees o ..."
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Cited by 166 (11 self)
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Causality on the gravity side of the AdS/CFT correspondence restricts motion on the moduli space of the N = 4 super Yang Mills theory by imposing a speed limit on how fast the scalar field may roll. This effect can be traced to higher derivative operators arising from integrating out light degrees of freedom near the origin. In the strong coupling limit of the theory, the dynamics is well approximated by the DiracBornInfeld Lagrangian for a probe D3brane moving toward the horizon of the AdS Poincare patch, combined with an estimate of the (ultimately suppressed) rate of particle and string production in the system. We analyze the motion of a rolling scalar field explicitly in the strong coupling regime of the field theory, and extend the analysis to cosmological systems obtained by coupling this type of field theory to four dimensional gravity. This leads to a mechanism for slow roll inflation for a massive scalar at subPlanckian VEV without need for a flat potential (realizing a version of kinflation in a microphysical framework). It also leads to a variety of novel FRW cosmologies, some of which
Distributions of flux vacua
 JHEP
"... Abstract: We give results for the distribution and number of flux vacua of various types, supersymmetric and nonsupersymmetric, in IIb string theory compactified on CalabiYau manifolds. We compare this with related problems such as counting attractor points. Contents ..."
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Cited by 165 (16 self)
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Abstract: We give results for the distribution and number of flux vacua of various types, supersymmetric and nonsupersymmetric, in IIb string theory compactified on CalabiYau manifolds. We compare this with related problems such as counting attractor points. Contents
Supersymmetry and Attractors
 Phys. Rev. D
, 1996
"... We find a general principle which allows one to compute the area of the horizon of N=2 extremal black holes as an extremum of the central charge. One considers the ADM mass equal to the central charge as a function of electric and magnetic charges and moduli and extremizes this function in the modul ..."
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Cited by 158 (14 self)
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We find a general principle which allows one to compute the area of the horizon of N=2 extremal black holes as an extremum of the central charge. One considers the ADM mass equal to the central charge as a function of electric and magnetic charges and moduli and extremizes this function in the moduli space (a minimum corresponds to a fixed point of attraction). The extremal value of the square of the central charge provides the area of the horizon, which depends only on electric and magnetic charges. The doubling of unbroken supersymmetry at the fixed point of attraction for N=2 black holes near the horizon is derived via conformal flatness of the BertottiRobinsontype geometry. These results provide an explicit model independent expression for the macroscopic BekensteinHawking entropy of N=2 black holes which is manifestly duality invariant. The presence of hypermultiplets in the solution does not affect the area formula. Various examples of the general formula are displayed. We outline the attractor mechanism in N=4,8 supersymmetries and the relation to the N=2 case. The entropyarea formula in five dimensions, recently discussed in the literature, is also seen to be obtained by extremizing the 5d central charge.
de Sitter string vacua from supersymmetric Dterms
 JHEP
, 2003
"... Abstract: We propose a new mechanism for obtaining de Sitter vacua in type IIB string theory compactified on (orientifolded) CalabiYau manifolds similar to those recently studied by Kachru, Kallosh, Linde and Trivedi (KKLT). dS vacuum appears in KKLT model after uplifting an AdS vacuum by adding an ..."
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Cited by 158 (19 self)
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Abstract: We propose a new mechanism for obtaining de Sitter vacua in type IIB string theory compactified on (orientifolded) CalabiYau manifolds similar to those recently studied by Kachru, Kallosh, Linde and Trivedi (KKLT). dS vacuum appears in KKLT model after uplifting an AdS vacuum by adding an antiD3brane, which explicitly breaks supersymmetry. We accomplish the same goal by adding fluxes of gauge fields within the D7branes, which induce a Dterm potential in the effective 4D action. In this way we obtain dS space as a spontaneously broken vacuum from a purely supersymmetric 4D action. We argue that our approach can be directly extended to heterotic string vacua, with the dilaton potential obtained from a combination of gaugino condensation and the Dterms generated by anomalous U(1) gauge groups. 1
Observational signatures and nongaussianities of general single field inflation
"... We perform a general study of primordial scalar nonGaussianities in single field inflationary models in Einstein gravity. We consider models where the inflaton Lagrangian is an arbitrary function of the scalar field and its first derivative, and the sound speed is arbitrary. We find that under reas ..."
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Cited by 157 (10 self)
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We perform a general study of primordial scalar nonGaussianities in single field inflationary models in Einstein gravity. We consider models where the inflaton Lagrangian is an arbitrary function of the scalar field and its first derivative, and the sound speed is arbitrary. We find that under reasonable assumptions, the nonGaussianity is completely determined by 5 parameters. In special limits of the parameter space, one finds distinctive “shapes ” of the nonGaussianity. In models with a small sound speed, several of these shapes would become potentially observable in the near future. Different limits of our formulae recover various previously known results. Contents
Moduli Stabilization from Fluxes in a Simple IIB Orientifold
, 2002
"... We study novel type IIB compactifications on the T 6 /Z2 orientifold. This geometry arises in the Tdual description of Type I theory on T 6, and one normally introduces 16 spacefilling D3branes to cancel the RR tadpoles. Here, we cancel the RR tadpoles either partially or fully by turning on thre ..."
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Cited by 149 (10 self)
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We study novel type IIB compactifications on the T 6 /Z2 orientifold. This geometry arises in the Tdual description of Type I theory on T 6, and one normally introduces 16 spacefilling D3branes to cancel the RR tadpoles. Here, we cancel the RR tadpoles either partially or fully by turning on threeform flux in the compact geometry. The resulting (super)potential for moduli is calculable. We demonstrate that one can find many examples of N = 1 supersymmetric vacua with greatly reduced numbers of moduli in this system. A few examples with N> 1 supersymmetry or complete supersymmetry breaking are also discussed.
Fourdimensional String Compactifications with DBranes, Orientifolds and Fluxes
"... This review article provides a pedagogical introduction into various classes of chiral string compactifications to four dimensions with Dbranes and fluxes. The main concern is to provide all necessary technical tools to explicitly construct fourdimensional orientifold vacua, with the final aim to ..."
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Cited by 147 (18 self)
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This review article provides a pedagogical introduction into various classes of chiral string compactifications to four dimensions with Dbranes and fluxes. The main concern is to provide all necessary technical tools to explicitly construct fourdimensional orientifold vacua, with the final aim to come as close as possible to the supersymmetric Standard Model. Furthermore, we outline the available methods to derive the resulting fourdimensional effective action. Finally, we summarize recent attempts to address the
Nongeometric Flux Compactifications
, 2006
"... We investigate a simple class of type II string compactifications which incorporate nongeometric “fluxes” in addition to “geometric flux” and the usual Hfield and RR fluxes. These compactifications are nongeometric analogues of the twisted torus. We develop Tduality rules for NSNS geometric and ..."
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Cited by 129 (5 self)
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We investigate a simple class of type II string compactifications which incorporate nongeometric “fluxes” in addition to “geometric flux” and the usual Hfield and RR fluxes. These compactifications are nongeometric analogues of the twisted torus. We develop Tduality rules for NSNS geometric and nongeometric fluxes, which we use to construct a superpotential for the dimensionally reduced fourdimensional theory. The resulting structure is invariant under Tduality, so that the distribution of vacua in the IIA and IIB theories is identical when nongeometric fluxes are included. This gives a concrete framework in which to investigate the possibility that generic string compactifications may be nongeometric in any duality frame. The framework developed in this paper also provides some concrete hints for how mirror symmetry can be generalized to compactifications with arbitrary Hflux, whose mirrors are generically nongeometric.
The effective action of type IIA CalabiYau orientifolds
"... The N = 1 effective action for generic type IIA CalabiYau orientifolds in the presence of background fluxes is computed from a KaluzaKlein reduction. The Kähler potential, the gauge kinetic functions and the fluxinduced superpotential are determined in terms of geometrical data of the CalabiYau ..."
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Cited by 95 (6 self)
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The N = 1 effective action for generic type IIA CalabiYau orientifolds in the presence of background fluxes is computed from a KaluzaKlein reduction. The Kähler potential, the gauge kinetic functions and the fluxinduced superpotential are determined in terms of geometrical data of the CalabiYau orientifold and the background fluxes. The moduli space is found to be a Kähler subspace of the N = 2 moduli space and shown to coincide with the moduli space arising in compactification of Mtheory on a specific class of G2 manifolds. The superpotential depends on all geometrical moduli and vanishes at leading order when background fluxes are turned off. The N = 1 chiral coordinates linearize the appropriate instanton actions such that instanton effects can lead to holomorphic corrections of the superpotential. Mirror symmetry between type IIA and type IIB orientifolds is shown to hold at the level of the effective action in the large volume – large complex structure limit.