# Spacetime and Universal Soft Modes --- Black Holes and Beyond

## TL;DR

This paper explores how chaotic string dynamics generate spacetime and soft modes in black holes and other spacetimes, proposing a UV/IR relation that explains horizon smoothness and symmetry breaking.

## Contribution

It extends the quantum black hole framework to include chaotic UV dynamics influencing IR spacetime and generalizes the approach to Rindler, de Sitter, and flat spacetimes.

## Key findings

- Chaotic string dynamics underpin black hole thermalization.
- UV/IR relation leads to symmetry breaking and horizon smoothness.
- Framework applies consistently across various spacetime geometries.

## Abstract

Recently, a coherent picture of the quantum mechanics of an evaporating black hole has been presented which reconciles unitarity with the predictions of the equivalence principle. The thermal nature of a black hole as viewed in a distant reference frame arises from entanglement between the hard and soft modes, generated by the chaotic dynamics at the string scale. In this paper, we elaborate on this picture, particularly emphasizing the importance of the chaotic nature of the string (UV) dynamics across all low energy species in generating large (IR) spacetime behind the horizon. Implications of this UV/IR relation include O(1) breaking of global symmetries at the string scale and a self-repair mechanism of black holes restoring the smoothness of their horizons. We also generalize the framework to other systems, including Rindler, de Sitter, and asymptotically flat spacetimes, and find a consistent picture in each case. Finally, we discuss the origin of the particular construction adopted in describing the black hole interior as well as the outside of a de Sitter horizon. We argue that the construction is selected by the quantum-to-classical transition, in particular the applicability of the Born rule in a quantum mechanical world.