Hypershadows of higher dimensional black objects: a case study of cohomogeneity-one d=5 Myers-Perry

TL;DR

This paper explores the concept of higher-dimensional black hole shadows, introducing the idea of hypershadows as a 3D structure seen by higher-dimensional observers, using the cohomogeneity-one Myers-Perry black hole in 5D as a case study.

Contribution

It proposes the notion of hypershadows as a higher-dimensional analogue to black hole shadows and computes a tridimensional hypershadow for a specific 5D black hole model.

Findings

Hypershadows are higher-dimensional structures beyond bidimensional shadows.

The study provides a method to compute tridimensional hypershadows for 5D black holes.

Results suggest observational features of higher-dimensional black objects differ from 4D cases.

Abstract

What does a black hole look like? In 1+3 spacetime dimensions, the optical appearance of a black hole is a bidimensional region in the observer's sky often called the black hole shadow, as supported by the EHT observations. In higher dimensions this question is more subtle and observational setup dependent. Previous studies considered the shadows of higher dimensional black holes to remain bidimensional. We argue that the latter should be regarded as a tomography of a higher dimensional structure, the hypershadow, which would be the structure "seen" by higher dimensional observers. As a case study we consider the cohomogeneity-one Myers-Perry black hole in 1+4 dimensions, and compute its tridimensional hypershadow.