639 research outputs found
Flux and Freund-Rubin Superpotentials in M-theory
We discuss the effective action for weak G_2 compactifications of M-theory.
The presence of fluxes acts as a source for the the axions and drives the
Freund-Rubin parameter to zero. The result is a stable non-supersymmetric
vacuum with a negative cosmological constant. We also give the superpotential
which generates the effective potential and discuss a simple model which aims
to incorporate the effects of supersymmetry breaking by the gauge sector.Comment: Discussion of KK-scale and cosmological scales revise
VOA[_4]
We take a peek at a general program that associates vertex (or, chiral) algebras to smooth 4-manifolds in such a way that operations on algebras mirror gluing operations on 4-manifolds and, furthermore, equivalent constructions of 4-manifolds give rise to equivalences (dualities) of the corresponding algebras
Remark on integrating out heavy moduli in flux compactification
We study two steps of moduli stabilization in type IIB flux compactification
with gaugino condensations. We consider the condition that one can integrate
out heavy moduli first with light moduli remaining. We give appendix, where
detail study is carried out for potential minima of the model with a six
dimensional compact space with , including the model, whose
respective moduli with are identified.Comment: 16 pages, late
Rigid surface operators and S-duality: some proposals
We study surface operators in the N=4 supersymmetric Yang-Mills theories with
gauge groups SO(n) and Sp(2n). As recently shown by Gukov and Witten these
theories have a class of rigid surface operators which are expected to be
related by S-duality. The rigid surface operators are of two types, unipotent
and semisimple. We make explicit proposals for how the S-duality map should act
on unipotent surface operators. We also discuss semisimple surface operators
and make some proposals for certain subclasses of such operators.Comment: 27 pages. v2: minor changes, added referenc
IIA String Theory on Calabi-Yau Fourfolds with Background Fluxes
Looking for string vacua with fixed moduli, we study compactifications of type IIA string theory on Calabi-Yau fourfolds in the presence of generic Ramond-Ramond fields. We explicitly derive the (super)potential induced by Ramond-Ramond fluxes performing a Kaluza-Klein reduction of the ten-dimensional effective action. This can be conveniently achieved in a formulation of the massive type IIA supergravity where all Ramond-Ramond fields appear in a democratic way. The result agrees with the general formula for the superpotential written in terms of calibrations. We further notice that for generic Ramond-Ramond fluxes all geometric moduli are stabilized and one finds non-supersymmetric vacua at positive values of the scalar potential
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