# Signals of Bursts from the Very Early Universe

## TL;DR

This paper explores potential observable signals from explosive events in the early universe, such as neutrino pulses and effects on the CMB, which could provide insights into primordial phenomena like black hole formation.

## Contribution

It analyzes how early universe bursts could produce detectable signals in the CMB, neutrino background, or x-ray emissions, linking primordial events to observable cosmological signatures.

## Key findings

- Possible signals include effects on small CMB regions
- Potential soft x-ray emissions from positron production
- Nonthermal relic neutrino background contributions

## Abstract

We consider possible observable signals from explosive events in the very early universe, ``bursts". These could be expected in connection with massive black hole or ``baby universe'' formation. We anticipate that such major disruptions of spacetime would be associated with neutrino and perhaps other pulses. While these seem to be not detectable directly, we discuss how they could lead to potentially observable signals. We analyze how the pulses from very early times may ``escape'', that is propagate to the last scattering epoch at the time $t_{cmb}$ and later, or alternatively be absorbed earlier, ``contained''. The possibly detectable signals include effects on small regions of the CMB, a soft x-ray resulting from positron production, or a nonthermal addition to the relic neutrino background.