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121
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
Towards inflation in string theory
 JCAP
, 2003
"... We investigate the embedding of brane inflation into stable compactifications of string theory. At first sight a warped compactification geometry seems to produce a naturally flat inflaton potential, evading one wellknown difficulty of braneantibrane scenarios. Careful consideration of the closed ..."
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Cited by 82 (9 self)
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We investigate the embedding of brane inflation into stable compactifications of string theory. At first sight a warped compactification geometry seems to produce a naturally flat inflaton potential, evading one wellknown difficulty of braneantibrane scenarios. Careful consideration of the closed string moduli reveals a further obstacle: superpotential stabilization of the compactification volume typically modifies the inflaton potential and renders it too steep for inflation. We discuss the nongeneric conditions under which this problem does not arise. We conclude that brane inflation models can only work if restrictive assumptions about the method of volume stabilization, the warping of the internal space, and the source of inflationary energy are satisfied. We argue that this may not be a real problem, given the large range of available fluxes and background geometries in string theory.
Boundary states of Dbranes and Dystrings
"... Polchinski’s recent construction of Dirichletbranes of RR charges, together with Witten’s mechanism for forming bound states of both NSNS charges and RR charges, provides a rigorous method to treat these dybranes. We construct the massless sector of boundary states of Dbranes, as well as of dy ..."
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Cited by 44 (1 self)
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Polchinski’s recent construction of Dirichletbranes of RR charges, together with Witten’s mechanism for forming bound states of both NSNS charges and RR charges, provides a rigorous method to treat these dybranes. We construct the massless sector of boundary states of Dbranes, as well as of dystrings of charge (p, 1). As a consequence, the string tension formula predicted by duality in the type IIB theory is obtained. October
Vallilo, “Superstrings in 2D backgrounds with RR flux and new extremal black holes,” Nucl
 Phys. B
, 2001
"... The hybrid formalism is used to quantize the superstring compactified to twodimensional targetspace in a manifestly spacetime supersymmetric manner. A quantizable sigma model action is then constructed for the Type II superstring in curved twodimensional supergravity backgrounds which can include R ..."
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Cited by 36 (2 self)
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The hybrid formalism is used to quantize the superstring compactified to twodimensional targetspace in a manifestly spacetime supersymmetric manner. A quantizable sigma model action is then constructed for the Type II superstring in curved twodimensional supergravity backgrounds which can include RamondRamond flux. Such curved backgrounds include CalabiYau fourfold compactifications with RamondRamond flux, and new extremal black hole solutions in twodimensional dilaton supergravity theory. These black hole solutions are a natural generalization of the CGHS model and might be possible to describe using a supergroup version of the SL(2,R)/U(1) WZW model. We also study some dynamical aspects of the new black holes, such as formation and evaporation.
Mapping class group action on quantum doubles
 Commun. Math. Phys
, 1995
"... Abstract: We study representations of the mapping class group of the punctured torus on the double of a finite dimensional possibly nonsemisimple Hopf algebra that arise in the construction of universal, extended topological field theories. We discuss how for doubles the degeneracy problem of TQFT’ ..."
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Cited by 35 (3 self)
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Abstract: We study representations of the mapping class group of the punctured torus on the double of a finite dimensional possibly nonsemisimple Hopf algebra that arise in the construction of universal, extended topological field theories. We discuss how for doubles the degeneracy problem of TQFT’s is circumvented. We find compact formulae for the S ±1matrices using the canonical, non degenerate forms of Hopf algebras and the bicrossed structure of doubles rather than monodromy matrices. A rigorous proof of the modular relations and the computation of the projective phases is supplied using Radford’s relations between the canonical forms and the moduli of integrals. We analyze the projective SL(2,Z)action on the center of Uq(sl2) for q an l = 2m + 1st root of unity. It appears that the 3m + 1dimensional representation decomposes into an m + 1dimensional finite representation and a 2mdimensional, irreducible representation. The latter is the tensor product of the two dimensional, standard representation of SL(2,Z) and the finite, mdimensional representation, obtained from the truncated TQFT Since the seminal paper of Atiyah [A] on the abstract definition of a topological quantum field theory (TQFT) much progress has been made in finding non trivial examples and
Charged Black Holes In TwoDimensional String Theory
, 1991
"... We discuss two dimensional string theories containing gauge fields, introduced either via coupling to open strings, in which case we get a BornInfeld type action, or via heterotic compactification. The solutions of the modified background field equations are charged black holes which exhibit intere ..."
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Cited by 31 (2 self)
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We discuss two dimensional string theories containing gauge fields, introduced either via coupling to open strings, in which case we get a BornInfeld type action, or via heterotic compactification. The solutions of the modified background field equations are charged black holes which exhibit interesting space time geometries. We also compute their masses and charges.
A Study of Black Brane Solutions in DDimensional Coupled Gravity System, preprint hepth/9903118
"... In this paper, we use only the equation of motion for an interacting system of gravity, dilaton and antisymmetric tensor to study the black brane solutions. By making use of the property of Schwarzian derivative, we obtain the complete solution of this system of equations. For some special values we ..."
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Cited by 23 (3 self)
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In this paper, we use only the equation of motion for an interacting system of gravity, dilaton and antisymmetric tensor to study the black brane solutions. By making use of the property of Schwarzian derivative, we obtain the complete solution of this system of equations. For some special values we obtain the wellknown BPS brane and black brane solutions.
An equivalence between momentum and charge in string theory
, 1992
"... ABSTRACT: It is shown that for a translationally invariant solution to string theory, spacetime duality interchanges the momentum in the symmetry direction and the axion charge per unit length. As one application, we show explicitly that charged black strings are equivalent to boosted (uncharged) bl ..."
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Cited by 18 (1 self)
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ABSTRACT: It is shown that for a translationally invariant solution to string theory, spacetime duality interchanges the momentum in the symmetry direction and the axion charge per unit length. As one application, we show explicitly that charged black strings are equivalent to boosted (uncharged) black strings. The extremal black strings (which correspond to the field outside of a fundamental macroscopic string) are equivalent to plane fronted waves describing strings moving at the speed of light. Despite extensive work over the past several years, we still lack a fundamental description of string theory, including a complete understanding of the basic objects that are involved and the principles which guide its construction. However there are several hints and suggestive clues which have been uncovered. Perhaps the most important is spacetime duality [1,2,3]. This is the fact that different spacetime backgrounds correspond to equivalent solutions in string theory. Spacetime duality is usually thought of in terms of relating small distances to large distances since in the simplest example of flat space with one direction identified, the duality relates radius R to radius α ′ /R. * Although this is certainly an important aspect of duality, there are many other consequences as well. For