Results 1 
4 of
4
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 ..."
Abstract

Cited by 60 (21 self)
 Add to MetaCart
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.
DBranes on generalized N = 1 backgrounds: superpotentials and Dterms
 JHEP 0606
"... We study the dynamics governing spacetime filling Dbranes on Type II flux backgrounds preserving fourdimensional N = 1 supersymmetry. The fourdimensional superpotentials and Dterms are derived. The analysis is kept on completely general grounds thanks to the use of recently proposed generalized ..."
Abstract

Cited by 11 (1 self)
 Add to MetaCart
(Show Context)
We study the dynamics governing spacetime filling Dbranes on Type II flux backgrounds preserving fourdimensional N = 1 supersymmetry. The fourdimensional superpotentials and Dterms are derived. The analysis is kept on completely general grounds thanks to the use of recently proposed generalized calibrations, which also allow one to show the direct link of the superpotentials and Dterms with BPS domain walls and cosmic strings respectively. In particular, our Dbrane setting reproduces the tension of Dterm strings found from purely fourdimensional analysis. The holomorphicity of the superpotentials is also studied and a moment map associated to the Dterms is proposed. Among different examples, we discuss an application to the study of D7branes on SU(3)structure backgrounds, which reproduces and generalizes some previous results.
The Strand, London
"... Germany. Abstract: In this talk we will discuss the low energy dynamics of nonBPS branes constructed as stable brane/antibrane pairs at an orbifold. In particular we will determine the effective field theory and compare its predictions with those of the full open string theory. While the position ..."
Abstract

Cited by 1 (0 self)
 Add to MetaCart
(Show Context)
Germany. Abstract: In this talk we will discuss the low energy dynamics of nonBPS branes constructed as stable brane/antibrane pairs at an orbifold. In particular we will determine the effective field theory and compare its predictions with those of the full open string theory. While the position and vector degrees of freedom of the branes have the familar form found in supersymmetric gauge theories, the massless modes originating in the tachyonic sector display novel noncommuting flat directions. We will show that these flat directions persist to all orders in α ′. Finally we will briefly discuss the open string loop corrections.
Mile End London E1 4NS
, 2001
"... ABSTRACT We investigate the local geometry on the moduli space of G2 structures that arises in compactifications of Mtheory on holonomy G2 manifolds. In particular, we determine the homogeneity properties of couplings of the associated N = 1, D = 4 supergravity under the scaling of moduli space coo ..."
Abstract
 Add to MetaCart
ABSTRACT We investigate the local geometry on the moduli space of G2 structures that arises in compactifications of Mtheory on holonomy G2 manifolds. In particular, we determine the homogeneity properties of couplings of the associated N = 1, D = 4 supergravity under the scaling of moduli space coordinates. We then find some brane solitons of N = 1, D = 4 supergravity that are associated with wrapping Mbranes on cycles of the compact space. These include cosmic strings and domain walls that preserve 1/2 of supersymmetry of the fourdimensional theory, and nonsupersymmetric electrically and magnetically charged black holes. The geometry of some of the black holes is that of nonextreme Mbrane configurations reduced to fourdimensions on a seven torus. 2