15 research outputs found
Non-perturbative orientifold transitions at the conifold
After orientifold projection, the conifold singularity in hypermultiplet
moduli space of Calabi-Yau compactifications cannot be avoided by geometric
deformations. We study the non-perturbative fate of this singularity in a local
model involving O6-planes and D6-branes wrapping the deformed conifold in Type
IIA string theory. We classify possible A-type orientifolds of the deformed
conifold and find that they cannot all be continued to the small resolution.
When passing through the singularity on the deformed side, the O-plane charge
generally jumps by the class of the vanishing cycle. To decide which classical
configurations are dynamically connected, we construct the quantum moduli space
by lifting the orientifold to M-theory as well as by looking at the
superpotential. We find a rich pattern of smooth and phase transitions
depending on the total sixbrane charge. Non-BPS states from branes wrapped on
non-supersymmetric bolts are responsible for a phase transition. We also
clarify the nature of a Z_2 valued D0-brane charge in the 6-brane background.
Along the way, we obtain a new metric of G_2 holonomy corresponding to an
O6-plane on the three sphere of the deformed conifold.Comment: 76 pages, references adde
The Holographic Dual of 2+1 Dimensional QFTs with N=1 SUSY and Massive Fundamental Flavours
The Maldacena Nastase solution is generalised to include massive fundamental
matter through the addition of a flavour profile. This gives a holographic dual
to N=1 SYM-CS with massive fundamental matter with a singularity free IR. We
study this solution in some detail confirming confinement and asymptotic
freedom. A recently proposed solution generating technique is then applied
which results in a new type-IIA supergravity solution. In a certain limit the
geometry of this solution is asymptotically AdS_4X Y, where Y is the metric at
the base of the Bryant-Salamon G_2 cone, which has topology S^3XS^3.Comment: 31 pages plus appendices, 6 figures. v3: Typos corrected, version to
appear in JHE
Branes and fluxes in special holonomy manifolds and cascading field theories
We conduct a study of holographic RG flows whose UV is a theory in 2+1
dimensions decoupled from gravity, and the IR is the N=6,8 superconformal fixed
point of ABJM. The solutions we consider are constructed by warping the
M-theory background whose eight spatial dimensions are manifolds of special
holonomies sp(1) times sp(1) and spin(7). Our main example for the spin(7)
holonomy manifold is the A8 geometry originally constructed by Cvetic, Gibbons,
Lu, and Pope. On the gravity side, our constructions generalize the earlier
construction of RG flow where the UV was N=3 Yang-Mills-Chern-Simons matter
system and are simpler in a number of ways. Through careful consideration of
Page, Maxwell, and brane charges, we identify the discrete and continuous
parameters characterizing each system. We then determine the range of the
discrete data, corresponding to the flux/rank for which the supersymmetry is
unbroken, and estimate the dynamical supersymmetry breaking scale as a function
of these data. We then point out the similarity between the physics of
supersymmetry breaking between our system and the system considered by
Maldacena and Nastase. We also describe the condition for unbroken
supersymmetry on class of construction based on a different class of spin(7)
manifolds known as B8 spaces whose IR is different from that of ABJM and
exhibit some interesting features.Comment: 51 pages, 12 figures. Update in quantization of G4 on B8 in equations
(5.12) and (5.13