Results 1  10
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17
Flux–induced Soft Supersymmetry Breaking in Chiral Type IIB Orientifolds with D3/D7–Branes
, 2004
"... We discuss supersymmetry breaking via 3–form fluxes in chiral supersymmetric type IIB orientifold vacua with D3 – and D7–branes. After a general discussion of possible choices of fluxes allowing for stabilizing of a part of the moduli, we determine the resulting effective action including all soft s ..."
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Cited by 78 (8 self)
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We discuss supersymmetry breaking via 3–form fluxes in chiral supersymmetric type IIB orientifold vacua with D3 – and D7–branes. After a general discussion of possible choices of fluxes allowing for stabilizing of a part of the moduli, we determine the resulting effective action including all soft supersymmetry breaking terms. We also extend the computation of our previous work [1] concerning the matter field metrics arising from various open string sectors, in particular focusing on the 1/2 BPS D3/D7–brane configuration. Afterwards, the F–theory lift of our constructions is investigated
A nogo theorem for string warped compactifications
, 2000
"... We give necessary conditions for the existence of perturbative heterotic and type II string warped compactifications preserving eight and four supersymmetries to four spacetime dimensions, respectively. In particular, we find that the only compactifications of heterotic string with the spin connecti ..."
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Cited by 60 (21 self)
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We give necessary conditions for the existence of perturbative heterotic and type II string warped compactifications preserving eight and four supersymmetries to four spacetime dimensions, respectively. In particular, we find that the only compactifications of heterotic string with the spin connection embedded in the gauge connection and type II strings are those on CalabiYau manifolds with constant dilaton. We obtain similar results for compactifications to six and to two dimensions.
A new handle on de Sitter compactifications
 JHEP
, 1998
"... We construct a large new class of de Sitter (and anti de Sitter) vacua of critical string theory from flux compactifications on products of Riemann surfaces. In the construction, the leading effects stabilizing the moduli are perturbative. We show that these effects selfconsistently dominate over s ..."
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Cited by 24 (11 self)
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We construct a large new class of de Sitter (and anti de Sitter) vacua of critical string theory from flux compactifications on products of Riemann surfaces. In the construction, the leading effects stabilizing the moduli are perturbative. We show that these effects selfconsistently dominate over standard estimates for further α ′ and quantum corrections, via tuning available from large flux and brane quantum numbers.
A tutorial on links between cosmic string theory and superstring theory
"... Cosmic superstrings are introduced to nonexperts. First Dbranes and (p,q) strings are discussed. Then we explain how tachyon condensation in the early universe may have produced F, D and (p,q) strings. Warped geometries which can render horizon sized superstrings relatively light are discussed. Va ..."
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Cited by 3 (0 self)
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Cosmic superstrings are introduced to nonexperts. First Dbranes and (p,q) strings are discussed. Then we explain how tachyon condensation in the early universe may have produced F, D and (p,q) strings. Warped geometries which can render horizon sized superstrings relatively light are discussed. Various warped geometries including the deformed conifold in the KlebanovStrassler geometry are reviewed and their warp factors are calculated. The decay rates for strings in the KS geometry are calculated and reasons for the necessity of orientifolds are reviewed. We then outline calculations of the intercommuting probability of F, D and (p,q) strings and explain in detail why cosmic superstring intercommuting probabilities can be small. We explore cosmic superstring networks. Their scaling properties are examined using the Velocity One Scale model and its extra dimensional extensions. Two different approaches and two sets of simulations are reviewed. Finally, we review in detail the gravitational wave amplitude calculations for strings with intercommuting probability
A note on fluxes in sixdimensional string theory backgrounds,” arXiv:hepth/0410283
"... We study the structure of warped compactifications of type IIB string theory to six spacetime dimensions. We find that the most general fourmanifold describing the internal dimensions is conformal to a Kähler manifold, in contrast with the heterotic case where the fourmanifold must be conformally ..."
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Cited by 3 (1 self)
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We study the structure of warped compactifications of type IIB string theory to six spacetime dimensions. We find that the most general fourmanifold describing the internal dimensions is conformal to a Kähler manifold, in contrast with the heterotic case where the fourmanifold must be conformally CalabiYau.
hepth/0412239 Volume Stabilization via α ′ Corrections in Type IIB Theory
, 2004
"... We consider the Type IIB string theory in the presence of various extra 7/7brane pairs compactified on a warped CalabiYau threefold that admits a conifold singularity. We demonstrate that the volume modulus can be stabilized perturbatively at a nonsupersymmetric AdS4/dS4 vacuum by the effective po ..."
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Cited by 1 (0 self)
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We consider the Type IIB string theory in the presence of various extra 7/7brane pairs compactified on a warped CalabiYau threefold that admits a conifold singularity. We demonstrate that the volume modulus can be stabilized perturbatively at a nonsupersymmetric AdS4/dS4 vacuum by the effective potential that includes the stringy (α′) 3 correction obtained by Becker et al. together with a combination of positive tension and anomalous negative tension terms generated by the additional 7braneantibrane pairs.
A Selftuning Exact Solution and the Nonexistence of Horizons in 5d GravityScalar System
, 2000
"... We present an exact thick domain wall solution with naked singularities to five dimensional gravity coupled with a scalar field with exponential potential. In our solution we found exactly the special coefficient of the exponent as coming from compactification of string theory with cosmological cons ..."
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Cited by 1 (0 self)
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We present an exact thick domain wall solution with naked singularities to five dimensional gravity coupled with a scalar field with exponential potential. In our solution we found exactly the special coefficient of the exponent as coming from compactification of string theory with cosmological constant. We show that this solution is selftuning when a 3brane is included. In searching for solution with horizon we found a similar exact solution with finetuned exponent coefficient with an integration constant. Failed to find a solution with horizon we prove the nonexistence of horizons. These naked singularities actually can’t be resolved by horizon. We also comment on the physical relevance of this solution.
hepph/0410302 Hierarchical Quark Masses and Small Mixing Angles from Warped Intersecting Brane Models
, 2004
"... We propose a novel mechanism for reproducing the realistic hierarchical structure of the observed CKM mixing matrix and quark masses by means of introducing a warped metric. We illustrate the method on the basis of a specific Type IIA intersecting brane model proposed by Ibáñez et al. The model is c ..."
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We propose a novel mechanism for reproducing the realistic hierarchical structure of the observed CKM mixing matrix and quark masses by means of introducing a warped metric. We illustrate the method on the basis of a specific Type IIA intersecting brane model proposed by Ibáñez et al. The model is compactified on a direct product of three tori, on which four Dbrane stacks wrap, and the intersections between two stacks collectively provide three generations of quarks and leptons. The exponential of the area formed by the intersection points corresponding to three matter fields is interpreted as the Yukawa coupling among them. It is known, however, that the Yukawa matrices for quarks are generically singular, and that it does not give definite mixing angles nor hierarchically suppressed quark masses. We show that the newly introduced warp effect on the internal manifold modifies the Yukawa matrix elements and generate hierarchical quark masses and CKM mixing angles.
hepph/0410302 Hierarchical Quark Masses and Small Mixing Angles from Warped Intersecting Brane Models
, 2005
"... We propose a novel mechanism for reproducing the realistic hierarchical structure of the observed CKM mixing matrix and quark masses by means of introducing a warped metric. We illustrate the method on the basis of a specific Type IIA intersecting brane model proposed by Ibáñez et al. The model is c ..."
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We propose a novel mechanism for reproducing the realistic hierarchical structure of the observed CKM mixing matrix and quark masses by means of introducing a warped metric. We illustrate the method on the basis of a specific Type IIA intersecting brane model proposed by Ibáñez et al. The model is compactified on a direct product of three tori, on which four Dbrane stacks wrap, and the intersections between two stacks collectively provide three generations of quarks and leptons. The exponential of the area formed by the intersection points corresponding to three matter fields is interpreted as the Yukawa coupling among them. It is known, however, that the Yukawa matrices for quarks are generically singular, and that it does not give definite mixing angles nor hierarchically suppressed quark masses. We show that the newly introduced warp effect on the internal manifold modifies the Yukawa matrix elements and generate hierarchical quark masses and CKM mixing angles.
FourFlux and Warped Heterotic MTheory
, 2000
"... In the framework of heterotic Mtheory compactified on a CalabiYau threefold ’times ’ an interval, the relation between geometry and fourflux is derived beyond first order. Besides the case with general flux which cannot be described by a warped geometry one is naturally led to consider two specia ..."
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In the framework of heterotic Mtheory compactified on a CalabiYau threefold ’times ’ an interval, the relation between geometry and fourflux is derived beyond first order. Besides the case with general flux which cannot be described by a warped geometry one is naturally led to consider two special types of fourflux in detail. One choice shows how the Mtheory relation between warped geometry and flux reproduces the analogous one of the weakly coupled heterotic string with torsion. The other one leads to a quadratic dependence of the CalabiYau volume with respect to the orbifold direction which avoids the problem with negative volume of the first order approximation. As in the first order analysis we still find that Newton’s Constant is bounded from below at just the phenomenologically relevant value. However, the bound does not require an ad hoc truncation of the orbifoldsize any longer. Finally we demonstrate explicitly that to leading order in κ2/3 no Cosmological Constant is induced in the fourdimensional lowenergy action. This is in accord with what one can expect from supersymmetry.