Results 1  10
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580
Field Dependent Gauge Couplings in Locally Supersymmetric Effective Quantum Field Theories,” Nucl. Phys. B422
, 1994
"... We investigate the field dependence of the gauge couplings of locally supersymmetric effective quantum field theories. We find that the Weyl rescaling of supergravity gives rise to WessZumino terms that affect the gauge couplings at the oneloop level. These WessZumino terms are crucial in assurin ..."
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Cited by 39 (0 self)
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We investigate the field dependence of the gauge couplings of locally supersymmetric effective quantum field theories. We find that the Weyl rescaling of supergravity gives rise to WessZumino terms that affect the gauge couplings at the oneloop level. These WessZumino terms are crucial in assuring supersymmetric consistency of both perturbative and nonperturbative gauge interactions. At the perturbative level, we distinguish between the holomorphic Wilsonian gauge couplings and the physicallymeasurable momentumdependent effective gauge couplings; the latter are affected by the Konishi and the superWeyl anomalies and their fielddependence is nonholomorphic. At the nonperturbative level, we show how consistency of the scalar potential generated by infraredstrong gauge interactions with the local supersymmetry requires a very specific form of the effective superpotential. We use this superpotential to determine the dependence of the supersymmetric condensates of a strongly interacting gauge theory on its (fielddependent) Wilsonian gauge coupling and the Yukawa couplings of the matter fields. The article concludes with the discussion of the fielddependent nonperturbative phenomena in the context of string unification. 2
RS1, custodial isospin and precision tests
 JHEP 0308
"... We study precision electroweak constraints within a RS1 model with gauge fields and fermions in the bulk. The electroweak gauge symmetry is enhanced to SU(2)L ×SU(2)R × U(1)B−L, thereby providing a custodial isospin symmetry sufficient to suppress excessive contributions to the T parameter. We then ..."
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Cited by 35 (1 self)
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We study precision electroweak constraints within a RS1 model with gauge fields and fermions in the bulk. The electroweak gauge symmetry is enhanced to SU(2)L ×SU(2)R × U(1)B−L, thereby providing a custodial isospin symmetry sufficient to suppress excessive contributions to the T parameter. We then construct complete models, complying with all electroweak constraints, for solving the hierarchy problem, without supersymmetry or large hierarchies in the fundamental couplings. Using the AdS/CFT correspondence our models can be interpreted as dual to a strongly coupled conformal Higgs sector with global custodial symmetry, gauge and fermionic matter being fundamental fields external to the CFT. This scenario has interesting collider signals, distinct from other RS models in the literature.
Theory of preasymptotic effects in weak inclusive decays; hepph/9405246
"... I give an introduction to the theory of preasymptotic effects based on the systematic OPE/HQET expansion in 1/mQ where mQ is the heavy quark mass. The general idea is explained in two most instructive examples, with an emphasis on pedagogical aspects. Some important results of the last year are revi ..."
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Cited by 27 (10 self)
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I give an introduction to the theory of preasymptotic effects based on the systematic OPE/HQET expansion in 1/mQ where mQ is the heavy quark mass. The general idea is explained in two most instructive examples, with an emphasis on pedagogical aspects. Some important results of the last year are reviewed. In discussing the issue of the quarkhadron duality, one of the basic ingredients of the theory, I prove that the operator product expansion per se is an asymptotic expansion. The behavior of the high order terms in this expansion determines the onset of duality and the accuracy of the duality relations. The factorial divergence of the highorder terms in OPE implies a sophisticated analytical structure in the αs plane, with terms of the type exp[ − exp(1/αs)]. Although the weak inclusive decays of heavy flavor hadrons are driven by weak interactions the theory of preasymptotic effects is an important applied branch of QCD. The theory has been gradually crystallizing from the eighties, with a decisive breakthrough achieved recently, in the last two or three years. I will try to summarize what we know and what
The minimal composite Higgs model
 Nucl. Phys. B
"... Composite Higgs models [1] represent an attractive variation of the Technicolor paradigm [2]. In these theories the Standard Model (SM) Higgs doublet is the bound state of a strongly interacting sector with flavor symmetry G. It forms at a scale fπ, the analog of the QCD pion decay constant, as the ..."
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Cited by 24 (0 self)
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Composite Higgs models [1] represent an attractive variation of the Technicolor paradigm [2]. In these theories the Standard Model (SM) Higgs doublet is the bound state of a strongly interacting sector with flavor symmetry G. It forms at a scale fπ, the analog of the QCD pion decay constant, as the Goldstone boson associated with the dynamical breaking of the global symmetry G. The couplings of the SM matter and gauge fields to the strong sector break G explicitly, and induce a oneloop Higgs potential that triggers the electroweak symmetry breaking (EWSB) at the scale v ≤ fπ. In the limit of a large separation ǫ = v/fπ ≪ 1, all the massive bound states of the strong sector decouple, and one is left with the lowenergy spectrum of the Standard Model. This means that all corrections to the electroweak precision observables constrained by LEP and SLD experiments will be suppressed by powers of ǫ. In this talk I will discuss an interesting realization of this old idea which has been recently found in the framework of extradimensional warped models
Strings on curved spacetimes: Black holes, torsion, and duality,” Nucl. Phys. B385
, 1992
"... We present a general discussion of strings propagating on noncompact coset spaces G/H in terms of gauged WZW models, emphasizing the role played by isometries in the existence of target space duality. Fixed points of the gauged transformations induce metric singularities and, in the case of abelian ..."
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Cited by 10 (1 self)
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We present a general discussion of strings propagating on noncompact coset spaces G/H in terms of gauged WZW models, emphasizing the role played by isometries in the existence of target space duality. Fixed points of the gauged transformations induce metric singularities and, in the case of abelian subgroups H, become horizons in a dual geometry. We also give a classification of models with a single timelike coordinate together with an explicit list for dimensions D ≤ 10. We study in detail the class of models described by the cosets SL(2, IR) ⊗ SO(1, 1) D−2 /SO(1, 1). For D ≥ 2 each coset represents two different spacetime geometries: (2D black hole)⊗IR D−2 and (3D black string)⊗IR D−3 with nonvanishing torsion. They are shown to be dual in such a way that the singularity of the former geometry (which is not due to a fixed point) is mapped to a regular surface (i.e. not even a horizon) in the latter. These cosets also lead to the conformal field theory description of known and new cosmological string models.
Modular invariant partition functions in the quantum Hall effect
"... We study the partition function for the lowenergy edge excitations of the incompressible electron fluid. On an annular geometry, these excitations have opposite chiralities on the two edges; thus, the partition function takes the standard form of rational conformal field theories. In particular, it ..."
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Cited by 10 (2 self)
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We study the partition function for the lowenergy edge excitations of the incompressible electron fluid. On an annular geometry, these excitations have opposite chiralities on the two edges; thus, the partition function takes the standard form of rational conformal field theories. In particular, it is invariant under modular transformations of the toroidal geometry made by the angular variable and the compact Euclidean time. The Jain series of plateaus have been described by two types of edge theories: the minimal models of the W1+∞ algebra of quantum areapreserving diffeomorphisms, and their nonminimal version, the theories with ̂ U(1) × ̂ SU(m) 1 affine algebra. We find modular invariant partition functions for the latter models. Moreover, we relate the Wen topological order to the modular transformations and the Verlinde fusion algebra. We find new, nondiagonal modular invariants which describe edge theories with extended symmetry algebra; their Hall conductivities match the experimental values beyond the Jain series.
NonEquilibrium Dynamics Of Phase Transitions: From The Early Universe To Chiral Condensates
"... In this brief review we introduce the methods of quantum field theory out of equilibrium and study the nonequilibrium aspects of phase transitions. Specifically we critically study the picture of the "slowroll" phase transition in the new inflationary models, we show that the instabiliti ..."
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Cited by 10 (0 self)
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In this brief review we introduce the methods of quantum field theory out of equilibrium and study the nonequilibrium aspects of phase transitions. Specifically we critically study the picture of the "slowroll" phase transition in the new inflationary models, we show that the instabilities that are the hallmark of the phase transition, that is the formation of correlated domains, dramatically change this picture. We analyze in detail the dynamics of phase separation in strongly supercooled phase transitions in Minkowski space. We argue that this is typically the situation in weakly coupled scalar theories. The effective evolution equations for the expectation value and the fluctuations of an inflaton field in a FRW cosmology are derived both in the loop expansion and in a selfconsistent nonperturbative scheme. Finally we use these nonequilibrium techniques and concepts to study the influence of quantum and thermal fluctuations on the dynamics of a proposed mechanism for the format...
Amplitude equation and pattern selection in Faraday waves
 Phys. Rev. E
, 1999
"... We present a systematic nonlinear theory of pattern selection for parametric surface waves (Faraday waves), not restricted to fluids of low viscosity. A standing wave amplitude equation is derived from the NavierStokes equations that is of gradient form. The associated Lyapunov function is calculat ..."
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Cited by 9 (0 self)
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We present a systematic nonlinear theory of pattern selection for parametric surface waves (Faraday waves), not restricted to fluids of low viscosity. A standing wave amplitude equation is derived from the NavierStokes equations that is of gradient form. The associated Lyapunov function is calculated for different regular patterns to determine the selected pattern near threshold. For fluids of large viscosity, the selected wave pattern consists of parallel stripes. At lower viscosity, patterns of square symmetry are obtained in the capillary regime (large frequencies). At lower frequencies (the mixed gravitycapillary regime), a sequence of sixfold (hexagonal), eightfold,... patterns are predicted. The regions of stability of the various patterns are in quantitative agreement with recent experiments conducted in large aspect ratio systems. 1 Typeset using REVTEXParametrically driven surface waves (also known as Faraday waves) appear on the free
G.R.: Stable hierarchical quantum Hall fluids as W1+∞ minimal models
 Nucl. Phys. B448 [FS
, 1995
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Extended fermion representation of multicharge 1/2BPS operators in AdS/CFT: Towards field theory of Dbranes,” arXiv:hepth/0510114
"... We extend the fermion representation of singlecharge 1/2BPS operators in the fourdimensional N = 4 super YangMills theory to general (multicharge) 1/2BPS operators such that all six directions of scalar fields play roles on an equal footing. This enables us to construct a fieldtheorectic repre ..."
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Cited by 8 (0 self)
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We extend the fermion representation of singlecharge 1/2BPS operators in the fourdimensional N = 4 super YangMills theory to general (multicharge) 1/2BPS operators such that all six directions of scalar fields play roles on an equal footing. This enables us to construct a fieldtheorectic representation for a secondquantized system of spherical D3branes in the 1/2BPS sector. The Fock space of D3branes is characterized by a novel exclusion principle (called ‘Dexclusion ’ principle), and also by a nonlocality which is consistent with the spacetime uncertainty relation. The Dexclusion principle is realized by composites of two operators, obeying the usual canonical anticommutation relation and the Cuntz algebra, respectively. The nonlocality appears as a consequence of a superselction rule associated with a symmetry which is related to the scale invariance of the super YangMills theory. The entropy of the socalled superstars, with multiple charges, which have been proposed to be geometries corresponding to the condensation of giant gravitons is discussed from our viewpoint and is argued to be consistent with the Dexclusion principle. Our construction may be regarded as a first step towards a possible new framework of general Dbrane field theory.