Xiaohua Ye | Searcharxiv

arXiv2024

A new energy inequality in AdS

We study time symmetric initial data for asymptotically AdS spacetimes with conformal boundary containing a spatial circle. Such $d$-dimensional initial data sets can contain $(d-2)$-dimensional minimal surfaces if the circle is contractible. We compute the minimum energy of a large class of such initial data as a function of the area $A$ of this minimal surface. The statement $E \ge E_{min}(A)$ is analogous to the Penrose inequality which bounds the energy from below by a function of the area of a $(d-1)$-dimensional minimal surface.

gr-qc↗

arXiv2022

An infinity of black holes

In general relativity (without matter), there is typically a one parameter family of static, maximally symmetric black hole solutions labelled by their mass. We show that there are situations with many more black holes. We study asymptotically anti-de Sitter solutions in six and seven dimensions having a conformal boundary which is a product of spheres cross time. We show that the number of families of static, maximally symmetric black holes depends on the ratio, $λ$, of the radii of the boundary spheres. As $λ$ approaches a critical value, $λ_{c}$, the number of such families becomes infinite. In each family, we can take the size of the black hole to zero, obtaining an infinite number of static, maximally symmetric non-black hole solutions. We discuss several applications of these results, including Hawking-Page phase transitions and the phase diagram of dual field theories on a product of spheres, new positive energy conjectures, and more.

hep-th↗