Results 1  10
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162
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 387 (6 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.
CFT’s from CalabiYau Fourfolds
 NUCL. PHYS. B584
, 1999
"... We consider F/M/Type IIA theory compactified to four, three, or two dimensions on a CalabiYau fourfold, and study the behavior near an isolated singularity in the presence of appropriate fluxes and branes. We analyze the vacuum and soliton structure of these models, and show that near an isolated ..."
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Cited by 274 (15 self)
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We consider F/M/Type IIA theory compactified to four, three, or two dimensions on a CalabiYau fourfold, and study the behavior near an isolated singularity in the presence of appropriate fluxes and branes. We analyze the vacuum and soliton structure of these models, and show that near an isolated singularity, one often generates massless chiral superfields and a superpotential, and in many instances in two or three dimensions one obtains nontrivial superconformal field theories. In the case of two dimensions, we identify some of these theories with certain KazamaSuzuki coset models, such as the N = 2 minimal models.
Superstrings and topological strings at large
 N”, J. Math. Phys
"... We embed the large N ChernSimons/topological string duality in ordinary superstrings. This corresponds to a large N duality between generalized gauge systems with N = 1 supersymmetry in 4 dimensions and superstrings propagating on noncompact CalabiYau manifolds with certain fluxes turned on. We a ..."
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Cited by 254 (27 self)
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We embed the large N ChernSimons/topological string duality in ordinary superstrings. This corresponds to a large N duality between generalized gauge systems with N = 1 supersymmetry in 4 dimensions and superstrings propagating on noncompact CalabiYau manifolds with certain fluxes turned on. We also show that in a particular limit of the N = 1 gauge theory system, certain superpotential terms in the N = 1 system (including deformations if spacetime is noncommutative) are captured to all orders in 1/N by the amplitudes of noncritical bosonic strings propagating on a circle with selfdual radius. We also consider Dbrane/antiDbrane system wrapped over vanishing cycles of compact CalabiYau manifolds and argue that at large N they induce a shift in the background to a topologically distinct CalabiYau, which we identify as the ground state system of the Brane/antiBrane system. August
Spacetime noncommutative field theories and unitarity
"... We study the perturbative unitarity of noncommutative scalar field theories. Field theories with spacetime noncommutativity do not have a unitary Smatrix. Field theories with only space noncommutativity are perturbatively unitary. This can be understood from string theory, since space noncommutati ..."
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Cited by 183 (4 self)
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We study the perturbative unitarity of noncommutative scalar field theories. Field theories with spacetime noncommutativity do not have a unitary Smatrix. Field theories with only space noncommutativity are perturbatively unitary. This can be understood from string theory, since space noncommutative field theories describe a low energy limit of string theory in a background magnetic field. On the other hand, there is no regime in which spacetime noncommutative field theory is an appropriate description of string theory. Whenever spacetime noncommutative field theory becomes relevant massive open string states cannot be neglected. May
Mtheory Dynamics on a Manifold of G2 Holonomy
"... We analyze the dynamics of Mtheory on a manifold of G2 holonomy that is developing a conical singularity. The known cases involve a cone on CP 3, where we argue that the dynamics involves restoration of a global symmetry, SU(3)/U(1) 2, where we argue that there are phase transitions among three pos ..."
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Cited by 175 (2 self)
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We analyze the dynamics of Mtheory on a manifold of G2 holonomy that is developing a conical singularity. The known cases involve a cone on CP 3, where we argue that the dynamics involves restoration of a global symmetry, SU(3)/U(1) 2, where we argue that there are phase transitions among three possible branches corresponding to three classical spacetimes, and S3 × S3 and its quotients, where we recover and extend previous results about smooth continuations between different spacetimes and relations to fourdimensional gauge theory. June
Compactifications of Type IIB Strings to Four Dimensions with Nontrivial Classical Potential
, 1996
"... Type IIB strings are compactified on a CalabiYau threefold. When CalabiYauvalued expectation values are given to the NSNS and RR threeform field strengths, the dilaton hypermultiplet becomes both electrically and magnetically charged. The resultant classical potential is calculated, and minima ..."
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Cited by 115 (0 self)
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Type IIB strings are compactified on a CalabiYau threefold. When CalabiYauvalued expectation values are given to the NSNS and RR threeform field strengths, the dilaton hypermultiplet becomes both electrically and magnetically charged. The resultant classical potential is calculated, and minima are found. At singular points in the moduli space, such as ArgyresDouglas points, supersymmetric minima are found. A formula for the classical potential in N = 2 supergravity is given which holds in the presence of both electric and magnetic charges.
Extremal Transitions and FiveDimensional supersymmetric field theories
, 1996
"... We study fivedimensional supersymmetric field theories with onedimensional Coulomb branch. We extend a previous analysis which led to nontrivial fixed points with En symmetry (E8, E7, E6, E5 = Spin(10), E4 = SU(5), E3 = SU(3) × SU(2), E2 = SU(2) × U(1) and E1 = SU(2)) by finding two new theories ..."
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Cited by 113 (11 self)
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We study fivedimensional supersymmetric field theories with onedimensional Coulomb branch. We extend a previous analysis which led to nontrivial fixed points with En symmetry (E8, E7, E6, E5 = Spin(10), E4 = SU(5), E3 = SU(3) × SU(2), E2 = SU(2) × U(1) and E1 = SU(2)) by finding two new theories: ˜ E1 with U(1) symmetry and E0 with no symmetry. The latter is a nontrivial theory with no relevant operators preserving the superPoincaré symmetry. In terms of string theory these new field theories enable us to describe compactifications of the type I ′ theory on S 1 /Z2 with 16, 17 or 18 background D8branes. These theories also play a crucial role in compactifications of Mtheory on Calabi– Yau spaces, providing physical models for the contractions of del Pezzo surfaces to points (thereby completing the classification of singularities which can occur at codimension one in Kähler moduli). The structure of the Higgs branch yields a prediction which unifies the known mathematical facts about del Pezzo transitions in a quite remarkable way.
GKZGeneralized Hypergeometric Systems in Mirror Symmetry of CalabiYau Hypersurfaces
, 1996
"... We present a detailed study of the generalized hypergeometric system introduced by Gel’fand, Kapranov and Zelevinski (GKZhypergeometric system) in the context of toric geometry. GKZ systems arise naturally in the moduli theory of CalabiYau toric varieties, and play an important role in application ..."
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Cited by 57 (16 self)
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We present a detailed study of the generalized hypergeometric system introduced by Gel’fand, Kapranov and Zelevinski (GKZhypergeometric system) in the context of toric geometry. GKZ systems arise naturally in the moduli theory of CalabiYau toric varieties, and play an important role in applications of the mirror symmetry. We find that the Gröbner basis for the socalled toric ideal determines a finite set of differential operators for the local solutions of the GKZ system. At the special point called the large radius limit, we find a close relationship between the principal parts of the operators in the GKZ system and the intersection ring of a toric variety. As applications, we analyze general three dimensional hypersurfaces of Fermat and nonFermat types with Hodge numbers up to h1,1 = 3. We also find and analyze several non LandauGinzburg models which are related to singular models.
Things fall apart: Topology change from winding tachyons,” arXiv:hepth/0502021
"... We argue that closed string tachyons drive two spacetime topology changing transitions – loss of genus in a Riemann surface and separation of a Riemann surface into two components. The tachyons of interest are localized versions of ScherkSchwarz winding string tachyons arising on Riemann surfaces i ..."
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Cited by 56 (6 self)
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We argue that closed string tachyons drive two spacetime topology changing transitions – loss of genus in a Riemann surface and separation of a Riemann surface into two components. The tachyons of interest are localized versions of ScherkSchwarz winding string tachyons arising on Riemann surfaces in regions of moduli space where stringscale tubes develop. Spacetime and worldsheet renormalization group analyses provide strong evidence that the decay of these tachyons removes a portion of the spacetime, splitting the tube into two pieces. We address the fate of the gauge fields and charges lost in the process, generalize it to situations with weak flux backgrounds, and use this process to study the type 0 tachyon, providing further evidence that its decay drives the theory subcritical. Finally, we discuss the timedependent dynamics of this topologychanging transition and find that it can occur more efficiently than analogous transitions on extended supersymmetric moduli spaces, which are limited by moduli trapping. January
Conifold transitions and mirror symmetry for complete intersections in Grassmannians
 IN GRASSMANNIANS, PREPRINT
, 1997
"... In this paper we show that conifold transitions between CalabiYau 3folds can be used for the construction of mirror manifolds and for the computation of the instanton numbers of rational curves on complete intersection CalabiYau 3folds in Grassmannians. Using a natural degeneration of Grassmanni ..."
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Cited by 54 (7 self)
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In this paper we show that conifold transitions between CalabiYau 3folds can be used for the construction of mirror manifolds and for the computation of the instanton numbers of rational curves on complete intersection CalabiYau 3folds in Grassmannians. Using a natural degeneration of Grassmannians G(k,n) to some Gorenstein toric Fano varieties P(k,n) with conifolds singularities which was recently described by Sturmfels, we suggest an explicit mirror construction for CalabiYau complete intersections X ⊂ G(k,n) of arbitrary dimension. Our mirror construction is consistent with the formula for the Lax operator conjectured by Eguchi, Hori and Xiong for gravitational