New vacua for type II string theory

Abstract

Lorentz-invariant expectation values for antisymmetric tensor field strengths in Calabi-Yau compactification of IIA string theory are considered. These are found to impart magnetic and/or electric charges to the dilaton hypermultiplet. This results in a potential which can have supersymmetric minima at zero coupling or at conifold points in the moduli space. The latter occurs whenever the dilaton charge is aligned with that of the light black hole at the conifold. It is shown that there is a flat direction extending from the conifold along which there is a black hole condensate whose strength is of order the string coupling g s . It is speculated that these new vacua correspond to string compactification on generalized Calabi-Yau spaces which have c 1 = 0 but are not Kahler.

D-brane monodromies from a matrix-factorization perspective

“…At the conifold point of Calabi-Yau hypersurfaces the (quantum) volume of the compactification space shrinks to zero size, while the (quantum) volume of lower-dimensional even cycles remains finite [40]. As a consequence a brane that wraps the compactification space without any lower-dimensional brane charges is massless at the conifold point [43,40]. Such a brane, X, potentially binds to the transported brane probe, P , as follows [30].…”

A stringy test of flux-induced isometry gauging

“…Since these components of B, in the absence of sources and non-trivial spacetime topology, are pure gauge and can hence be set to zero in the brane action, neither a contribution to S inst,class depending on a nor a vertex operator coupling a to degrees of freedom on the brane arise. 1 We hence do not worry about brane instanton corrections lifting k F , and in the case of k H , we can focus on the shift symmetry part of the isometry in ξ i . 2 For E2 branes (the instantonic version of D2 branes), the classical contribution already appears to generically break any isometry involving a shift symmetry in the fields ξ i .…”

“…Dimensionally reducing 10d supergravity on a Calabi-Yau manifold in a background of fluxes gives rise to gauged supergravity in four dimensions [1]. The 'gauged' refers to the fact that the hypermultiplets are charged under some of the vector multiplets.…”

General type IIB fluxes with SU(3) structures

“…If one neglects the back reaction of the fluxes on the geometry, one can simply perform a KK-reduction on a Calabi-Yau space yielding the explicit form of the potential. This is especially reliable as long as one has only RR or only NS fluxes, see [1,2,3]. The other approach discusses background fluxes as specific torsion components of the internal geometry and classifies the vacua with respect to the corresponding G-structures [4,5,6,7,8,9,10,11].…”