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Jose J. Fernandez-Melgarejo

Publications and source records attributed to Jose J. Fernandez-Melgarejo.

21 records · Page 2Linked to original sources

$T$-folds from Yang-Baxter deformations

Yang-Baxter (YB) deformations of type IIB string theory have been well studied from the viewpoint of classical integrability. Most of the works, however, are focused upon the local structure of the deformed geometries and the global structure still remains unclear. In this work, we reveal a non-geometric aspect of YB-deformed backgrounds as $T$-fold by explicitly showing the associated $\mathrm{O}(D,D;\mathbb{Z})$ $T$-duality monodromy. In particular, the appearance of an extra vector field in the generalized supergravity equations (GSE) leads to the non-geometric $Q$-flux. In addition, we study a particular solution of GSE that is obtained by a non-Abelian $T$-duality but cannot be expressed as a homogeneous YB deformation, and show that it can also be regarded as a $T$-fold. This result indicates that solutions of GSE should be non-geometric quite in general beyond the YB deformation.

hep-th↗

The Odd story of $α'$-corrections

The $α'$-deformed frame-like Double Field Theory (DFT) is a T-duality and gauge invariant extension of DFT in which generalized Green-Schwarz transformations provide a gauge principle that fixes the higher-derivative corrections. It includes all the first order $α'$-corrections of the bosonic and heterotic string low energy effective actions and of the Hohm-Siegel-Zwiebach $α'$-geometry. Here we gauge this theory and parameterize it in terms of a frame, a two-form, a dilaton, gauge vectors and scalar fields. This leads to a unified framework that extends the previous construction by including all duality constrained interactions in generic (gauged/super)gravity effective field theories in arbitrary number of dimensions, to first order in $α'$.

hep-th↗

A New Approach to Non-Abelian Hydrodynamics

We present a new approach to describe hydrodynamics carrying non-Abelian macroscopic degrees of freedom. Based on the Kaluza-Klein compactification of a higher-dimensional neutral dissipative fluid on a group manifold, we obtain a d=4 colored dissipative fluid coupled to Yang-Mills gauge field. We calculate the transport coefficients of the new fluid, which show the non-Abelian character of the gauge group. In particular, we obtain group-valued terms in the gradient expansions and response quantities such as the conductivity matrix and the chemical potentials. While using SU(2) for simplicity, this approach is applicable to any gauge group. Resulting a robust description of non-Abelian hydrodynamics, we discuss some links between this system and quark-gluon plasma and fluid/gravity duality.

hep-th↗