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Fivebranes, Membranes And NonPerturbative String Theory
, 1995
"... Nonperturbative instanton corrections to the moduli space geometry of type IIA string theory compactified on a CalabiYau space are derived and found to contain order e \Gamma1=g s contributions, where g s is the string coupling. The computation reduces to a weighted sum of supersymmetric extrema ..."
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Cited by 395 (7 self)
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Nonperturbative instanton corrections to the moduli space geometry of type IIA string theory compactified on a CalabiYau space are derived and found to contain order e \Gamma1=g s contributions, where g s is the string coupling. The computation reduces to a weighted sum of supersymmetric extremal maps of strings, membranes and fivebranes into the CalabiYau space, all three of which enter on equal footing. It is shown that a supersymmetric 3cycle is one for which the pullback of the Kahler form vanishes and the pullback of the holomorphic threeform is a constant multiple of the volume element. Quantum mirror symmetry relates the sum in the IIA theory over supersymmetric, odddimensional cycles in the CalabiYau space to a sum in the IIB theory over supersymmetric, evendimensional cycles in the mirror.
The topological vertex
, 2003
"... We construct a cubic field theory which provides all genus amplitudes of the topological Amodel for all noncompact toric CalabiYau threefolds. The topology of a given Feynman diagram encodes the topology of a fixed CalabiYau, with Schwinger parameters playing the role of Kähler classes of the th ..."
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Cited by 175 (24 self)
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We construct a cubic field theory which provides all genus amplitudes of the topological Amodel for all noncompact toric CalabiYau threefolds. The topology of a given Feynman diagram encodes the topology of a fixed CalabiYau, with Schwinger parameters playing the role of Kähler classes of the threefold. We interpret this result as an operatorial computation of the amplitudes in the Bmodel mirror which is the quantum KodairaSpencer theory. The only degree of freedom of this theory is an unconventional chiral scalar on a Riemann surface. In this setup we identify the Bbranes on the mirror Riemann
Shopbot Economics
 JAAMAS
, 1999
"... . Shopbots are agents that search the Internet for information pertaining to the price and quality of goods or services. With the advent of shopbots, a dramatic reduction in search costs is imminent, which promises (or threatens) to radically alter market behavior. This research includes the proposa ..."
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Cited by 67 (7 self)
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. Shopbots are agents that search the Internet for information pertaining to the price and quality of goods or services. With the advent of shopbots, a dramatic reduction in search costs is imminent, which promises (or threatens) to radically alter market behavior. This research includes the proposal and theoretical analysis of a simple economic model which is intended to capture some of the essence of shopbots, and attempts to shed light on their potential impact on markets. Moreover, experimental simulations of an economy of software agents are described, which are designed to model the dynamic interaction of electronic buyers, sellers, and shopbots. This study forms part of a larger research program that aims to provide new insights on the impact of agent and information technology on the nascent information economy. 1 Introduction Shopbots, agents that automatically search the Internet for goods and services on behalf of consumers, herald a future in which autonomous agents become...
Cosmological implications of dynamical supersymmetry breaking,” Phys
 Rev. D
, 1994
"... We provide a taxonomy of dynamical supersymmetry breaking theories, and discuss the cosmological implications of the various types of models. Models in which supersymmetry breaking is produced by chiral superfields which only have interactions of gravitational strength (e.g. string theory moduli) ar ..."
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Cited by 43 (0 self)
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We provide a taxonomy of dynamical supersymmetry breaking theories, and discuss the cosmological implications of the various types of models. Models in which supersymmetry breaking is produced by chiral superfields which only have interactions of gravitational strength (e.g. string theory moduli) are inconsistent with standard big bang nucleosynthesis unless the gravitino mass is greater than O(3) × 104 GeV. This problem cannot be solved by inflation. Models in which supersymmetry is dynamically broken by renormalizable interactions in flat space have no such cosmological problems. Supersymmetry can be broken either in a hidden or the visible sector. However hidden sector models suffer from several naturalness problems and have difficulties in producing an acceptably large gluino mass.
Determinant formulae and unitarity for the N = 2 superconformal algebras in two dimensions or exact results on string compacti
, 1986
"... Determinant formulae are presented for the periodic, antiperiodic and twisted N = 2 superconformal gebras in two dimensions, and a classification is derived of the unitary highest weight representations. Physical realisations of several of these representations are discussed. In particular, it is no ..."
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Cited by 22 (0 self)
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Determinant formulae are presented for the periodic, antiperiodic and twisted N = 2 superconformal gebras in two dimensions, and a classification is derived of the unitary highest weight representations. Physical realisations of several of these representations are discussed. In particular, it is noted that the unitarity constraints apply to string compactification, giving results which are nonperturbative in the compactification radius. The inFinitedimensional conformal algebra of the twodimensional cylinder, the Virasoro algebra, is the gauge algebra of the world surface of the covariantly quantized bosonic string [ 1]. The Virasoro algebra also acts in the operator representation f twodimensional critical phenomena [2], where its unitary representation theory gives constraints on the possible values of critical indices [3]. In the investigation ofunitarity, the basic technical tool is the determinant formula conjectured by Kac [4] and proved by Feigin and Fuchs [5]. The gauge algebras of the supersymmetric string, the Ramond [6] and NeveuSchwarz [7] algebras, are the N = 1 superconformal algebras on the cylinder. The N = 1 algebras are realized in supersymmetric critical phenomena, nd unitarity again restricts the possible values of critical indices, permitting the identification of physical systems with supersymmetric critical behavior [3,8]. The NeveuSchwarz determinant formula [4] and the Ramond formula [8,9] were proved by Meurman and RochaCaridi [10] and by
Irrational axions as a solution of the strong CP problem in an eternal universe,” Phys
 Lett. B
, 1991
"... We exhibit a novel solution of the strong CP problem, which does not involve any massless particles. The low energy effective Lagrangian of our model involves a discrete spacetime independent axion field which can be thought of as a parameter labeling a dense set of θ vacua. In the full theory this ..."
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Cited by 12 (3 self)
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We exhibit a novel solution of the strong CP problem, which does not involve any massless particles. The low energy effective Lagrangian of our model involves a discrete spacetime independent axion field which can be thought of as a parameter labeling a dense set of θ vacua. In the full theory this parameter is seen to be dynamical, and the model seeks the state of lowest energy, which has θeff = 0. The processes which mediate transitions between θ vacua involve heavy degrees of freedom and are very slow. Consequently, we do not know whether our model can solve the strong CP problem in a universe which has been cool for only a finite time. We present several speculations about the cosmological evolution of our model. Sep. 19911. Introduction and a 1+1 Dimensional Example There have been a number of mechanisms proposed for resolving the strong CP problem of Quantum Chromodynamics (QCD). Most of them are either ruled out by experiment or only marginally consistent with the combination of experimental data and conventional cosmology1. In the present note we would like to present a new solution of the strong
Matrix models of 2D gravity
, 1991
"... These are introductory lectures for a general audience that give an overview of the subject of matrix models and their application to random surfaces, 2d gravity, and string theory. They are intentionally 1.5 years out of date. Lectures given July 22–25, 1991 at Trieste summer school 12/91 0. Canned ..."
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Cited by 9 (0 self)
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These are introductory lectures for a general audience that give an overview of the subject of matrix models and their application to random surfaces, 2d gravity, and string theory. They are intentionally 1.5 years out of date. Lectures given July 22–25, 1991 at Trieste summer school 12/91 0. Canned Diatribe, Introduction, and Apologies................... 1 1. Discretized surfaces, matrix models, and the continuum limit............ 3 1.1. Discretized surfaces............................. 3 1.2. Matrix models............................... 5 1.3. The continuum limit............................ 9
The Master equation of 2D string theory
 Nucl. Phys. B
, 1992
"... A general method is presented for deriving onshell Wardidentities in (2D) string theory. It is shown that all treelevel Ward identities can be summarized in a single quadratic differential equation for the generating function of all amplitudes. This result is extended to loop amplitudes and leads ..."
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Cited by 5 (0 self)
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A general method is presented for deriving onshell Wardidentities in (2D) string theory. It is shown that all treelevel Ward identities can be summarized in a single quadratic differential equation for the generating function of all amplitudes. This result is extended to loop amplitudes and leads to a master equation à la BatalinVilkovisky for the complete partition function. supported by the W.M. Keck Foundation.
SUITP 01/56 hepth/0112204 The Trouble with De Sitter Space
, 2003
"... In this paper we assume the de Sitter space version of black hole Complementarity which states that a single causal patch of de Sitter space is described as an isolated finite temperature cavity bounded by a horizon which allows no loss of information. We discuss the how the symmetries of de Sitter ..."
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In this paper we assume the de Sitter space version of black hole Complementarity which states that a single causal patch of de Sitter space is described as an isolated finite temperature cavity bounded by a horizon which allows no loss of information. We discuss the how the symmetries of de Sitter space should be implemented. Then we prove a no go theorem for implementing the symmetries if the entropy is finite. Thus we must either give up the finiteness of de Sitter space entropy or the exact symmetry of the classical space. Each has interesting implications for the very long time behavior. We argue that the lifetime of a de Sitter phase can not exceed the Poincare recurrence time. This is supported by recent results of Kachru, Kallosh, Linde and Trivedi. 1 Thermofield Dynamics and Horizons An exact formulation of the quantum theory of an accelerating universe appears to be very elusive [1]. Thus far the holographic principle [2, 3, 4] has not produced a dual description of de Sitter space analogous to the holographic duality between anti–de Sitter space and Super Yang Mills theory [5, 6, 7]