3,658 research outputs found
SQCD Vacua and Geometrical Engineering
We consider the geometrical engineering constructions for the N = 1 SQCD
vacua recently proposed by Giveon and Kutasov. After one T-duality, the
geometries with wrapped D5 branes become N = 1 brane configurations with NS
branes and D4 branes. The field theories encoded by the geometries contain
extra massive adjoint fields for the flavor group. After performing a flop, the
geometries contain branes, antibranes and branes wrapped on non-holomorphic
cycles. The various tachyon condensations between pairs of wrapped D5 branes
and anti D5 branes together with deformations of the cycles give rise to a
variety of supersymmetric and metastable non-supersymmetric vacua.Comment: 21 Pages, Latex, 8 Figure
Puzzles for Matrix Models of Chiral Field Theories
We summarize the field-theory/matrix model correspondence for a chiral N=1
model with matter in the adjoint, antisymmetric and conjugate symmetric
representations as well as eight fundamentals to cancel the chiral anomaly. The
associated holomorphic matrix model is consistent only for two fundamental
fields, which requires a modification of the original Dijkgraaf-Vafa
conjecture. The modified correspondence holds in spite of this mismatch.Comment: Contribution to the proceedings of the 36th International Symposium
Ahrenshoop, Berlin, August 26-30, 2003; 6 Page
Toward the Gravity Dual of Heterotic Small Instantons
The question of what happens when the heterotic SO(32) instanton becomes
small was answered sometime back by Witten. The heterotic theory develops an
enhanced Sp(2k) gauge symmetry for k small instantons, besides the allowed
SO(32) gauge symmetry. An interesting question now is to ask what happens when
we take the large k limit. In this paper we argue that in some special cases,
where Gauss' law allows the large k limit, the dynamics of the large k small
instantons can be captured by a dual gravitational description. For the cases
that we elaborate in this paper, the gravity duals are non-Kahler manifolds
although in general they could be non-geometric. These small instantons are
heterotic five-branes and the duality allows us to study the strongly coupled
field theories on these five-branes. We review and elaborate on some of the
recent observations pointing towards this duality, and argue that in certain
cases the gauge/gravity duality may be understood as small instanton
transitions under which the instantons smoothen out and consequently lose the
Sp(2k) gauge symmetry. This may explain how branes disappear on the dual side
and are replaced by fluxes. We analyse the torsion classes before and after the
transitions, and discuss briefly how the ADHM sigma model and related vector
bundles could be studied for these scenarios.Comment: 47 pages, 3 eps figures, LaTex, JHEP3 file; v2: Another consistency
check added, typos corrected and a reference added; v3: Text expanded a bit,
minor typos corrected and a few references updated. Final version to appear
in Phys. Rev.
Introducing Latent Timbre Synthesis
We present the Latent Timbre Synthesis (LTS), a new audio synthesis method
using Deep Learning. The synthesis method allows composers and sound designers
to interpolate and extrapolate between the timbre of multiple sounds using the
latent space of audio frames. We provide the details of two Variational
Autoencoder architectures for LTS, and compare their advantages and drawbacks.
The implementation includes a fully working application with graphical user
interface, called \textit{interpolate\_two}, which enables practitioners to
explore the timbre between two audio excerpts of their selection using
interpolation and extrapolation in the latent space of audio frames. Our
implementation is open-source, and we aim to improve the accessibility of this
technology by providing a guide for users with any technical background
de Sitter Vacua in Type IIB String Theory: Classical Solutions and Quantum Corrections
We revisit the classical theory of ten-dimensional two-derivative gravity coupled to fluxes, scalar fields, D-branes, anti D-branes and Orientifold-planes. We show that such set-ups do not give rise to a four-dimensional positive curvature spacetime with the isometries of de Sitter spacetime. We further argue that a de Sitter solution in type IIB theory may still be achieved if the higher-order curvature corrections are carefully controlled. Our analysis relies on the derivation of the de Sitter condition from an explicit background solution by going beyond the supergravity limit of type IIB theory. As such this also tells us how the background supersymmetry should be broken and under what conditions D-term uplifting can be realized with non self-dual fluxes
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