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