arXiv subjects

M. Oyarzo

Publications and source records attributed to M. Oyarzo.

3 recordsLinked to original sources

arXiv2025

Warped-AdS$_3$ Near-Horizon Geometries From TsT Transformations

We provide a string theory realisation of a two-parameter family of Type IIB supergravity solutions of the form ${\rm WAdS}_3 \times {\rm WS}^3 \times M_4$, as near-horizon geometries of supersymmetric backgrounds involving D1-D5 branes, D3-branes and NS5-branes. We show that the full solutions, as well as their near-horizon limits, preserve four supercharges. We end by presenting a new doubly-deformed warped black hole solution and study its thermodynamical properties.

hep-th↗

arXiv2025

Supersymmetric Warped Solutions from Type IIB Orientifold Reduction

We construct a family of supersymmetric solutions in Type IIB supergravity of the form ${\rm WAdS}_3\times {\rm WS}^3\times T^4$, where ${\rm WAdS}_3$ and ${\rm WS^3}$ denote a warped anti-de Sitter spacetime and a warped 3-sphere, respectively, while $T^4$ denotes an internal 4-torus. These backgrounds are constructed by uplifting corresponding solutions in the $D=6$, $\mathcal{N}=(1,1)$ ungauged supergravity resulting from the compactification of Type IIB supergravity on a $T^4/\mathbb{Z}_2$-orientifold. More specifically, the supersymmetric solutions are ${\rm WAdS}_3\times {\rm WS}^3\times T^4$ with lightlike warped AdS$_3$ and ${\rm WAdS}_3\times {\rm S}^3\times T^4$ in which the warping of AdS$_3$ is generic. Moreover, we also construct solutions in the form of a warped product $\mathrm{LM}^3_{ζ,ω}\times_{\rm w} \mathrm{S}^3\times T^4$ of a 2-parameter deformation $\mathrm{LM}^3_{ζ,ω}$ of ${\rm AdS}_3$ and a three-sphere. We discuss the relation of these backgrounds to known solutions.

hep-th↗

arXiv2024

Black Hole shadows of $α'$-corrected black holes

In this paper we study the qualitative features induces by corrections to GR coming from String Theory, on the shadows of rotating black holes. We deal with the slowly rotating black hole solutions up to order $\mathcal{O}(a^3)$, to first order in $α'$, including also the dilaton. We provide a detailed characterization of the geometry, as well as the innermost stable circular orbit (ISCO) and photon ring, and then we proceed to obtain the black hole images within the relativistic thin-disk model. We characterize the images by computing the diameter, displacement and asymmetry. A comparison with the Kerr case, indicates that all these quantities grow due to the $α'$ correction, and that the departure from GR for different observable is enhanced depending on the angle of view, namely for the diameter the maximum departure is obtained when the system is face-on, while for the displacement and asymmetry the departure from GR is maximized for edge-on point of view.

gr-qc↗