The Young Modulus of Black Strings and the Fine Structure of Blackfolds

TL;DR

This paper extends the blackfold approach by calculating the elastic response (Young modulus) of black branes, revealing their fine structure and applying these results to predict properties of higher-dimensional black rings and multi-spinning black holes.

Contribution

It introduces a relativistic generalization of the Young modulus for black branes and demonstrates its application to black ring and multi-spinning black hole configurations.

Findings

Calculated the Young modulus of black branes analytically.

Predicted properties of black rings in higher dimensions.

Confirmed blackfold predictions with known solutions.

Abstract

We explore corrections in the blackfold approach, which is a worldvolume theory capturing the dynamics of thin black branes. The corrections probe the fine structure of the branes, going beyond the approximation in which they are infinitely thin, and account for the dipole moment of worldvolume stress-energy as well as the internal spin degrees of freedom. We show that the dipole correction is induced elastically by bending a black brane. We argue that the long-wavelength linear response coefficient capturing this effect is a relativistic generalization of the Young modulus of elastic materials and we compute it analytically. Using this we draw predictions for black rings in dimensions greater than six. Furthermore, we employ our corrected blackfold equations to various multi-spinning black hole configurations in the blackfold limit, finding perfect agreement with known analytic solutions.