# An Introductory Review on Cosmic Reionization

**Authors:** John H. Wise  
**arXiv:** [1907.06653](https://arxiv.org/abs/1907.06653)  
**Date:** 2019-07-15  
**Summary page:** https://www.summarizepaper.com/en/arxiv-id/1907.06653v1/

## Key points

- Cosmic reionization is the final phase transition in the early universe
- Ultraviolet and X-ray radiation from first galaxies heated and ionized surroundings
- Entire intergalactic medium was affected
- Evidence suggests cosmic reionization ended about one billion years after Big Bang
- Uncertainties remain, but will be clarified with upcoming optical, infrared, and radio facilities
- John H. Wise's article provides an introduction to theoretical and observational aspects of cosmic reionization
- Cosmic reionization is important in understanding early galaxy formation and cosmology

## Summary

Cosmic reionization is the final phase transition that occurred during the formative stages of the universe. It involved ultraviolet and X-ray radiation escaping from the first generations of galaxies, which then heated and ionized their surroundings. This led to the entire intergalactic medium being affected. Evidence suggests cosmic reionization ended approximately one billion years after the Big Bang. However, uncertainties remain that will be clarified with upcoming optical, infrared, and radio facilities in the next decade. John H. Wise's article "An Introductory Review on Cosmic Reionization" provides an introduction to both theoretical and observational aspects of cosmic reionization and how they contribute to our understanding of early galaxy formation and cosmology. The review offers a comprehensive overview of cosmic reionization and its importance in shaping our knowledge of the universe's evolution.