25 research outputs found
Boundary Terms, Spinors and Kerr/CFT
Similarly as in AdS/CFT, the requirement that the action for spinors be
stationary for solutions to the Dirac equation with fixed boundary conditions
determines the form of the boundary term that needs to be added to the standard
Dirac action in Kerr/CFT. We determine this boundary term and make use of it to
calculate the two-point function for spinor fields in Kerr/CFT. This two-point
function agrees with the correlator of a two dimensional relativistic conformal
field theory.Comment: 15 page
Moduli Stabilization in Type IIB Orientifolds (I)
We discuss flux quantization and moduli stabilization in toroidal type IIB
Z_N - or Z_N x Z_M -orientifolds, focusing mainly on their orbifold limits.
After presenting a detailed discussion of their moduli spaces and effective
actions, we study the supersymmetric vacuum structure of these models and
derive criteria for the existence of stable minima. Furthermore, we briefly
investigate the models away from their orbifold points and comment on the
microscopic origin of their non-perturbative superpotentials.Comment: 97 pages + 2 figs, harvma
Lectures on Nongeometric Flux Compactifications
These notes present a pedagogical review of nongeometric flux
compactifications. We begin by reviewing well-known geometric flux
compactifications in Type II string theory, and argue that one must include
nongeometric "fluxes" in order to have a superpotential which is invariant
under T-duality. Additionally, we discuss some elementary aspects of the
worldsheet description of nongeometric backgrounds. This review is based on
lectures given at the 2007 RTN Winter School at CERN.Comment: 31 pages, JHEP
A ten-dimensional action for non-geometric fluxes
The NSNS Lagrangian of ten-dimensional supergravity is rewritten via a change
of field variables inspired by Generalized Complex Geometry. We obtain a new
metric and dilaton, together with an antisymmetric bivector field which leads
to a ten-dimensional version of the non-geometric Q-flux. Given the involved
global aspects of non-geometric situations, we prescribe to use this new
Lagrangian, whose associated action is well-defined in some examples
investigated here. This allows us to perform a standard dimensional reduction
and to recover the usual contribution of the Q-flux to the four-dimensional
scalar potential. An extension of this work to include the R-flux is discussed.
The paper also contains a brief review on non-geometry.Comment: 47 pages; v2: minor modifications, references added, version to be
published in JHE