# Inflation inside non-topological defects and scalar black holes

**Authors:** Y. Brihaye, F. Cônsole, B. Hartmann  
**arXiv:** [2010.15625](https://arxiv.org/abs/2010.15625)  
**Date:** 2020-10-29  
**Summary page:** https://www.summarizepaper.com/en/arxiv-id/2010.15625v1/

## Key points

- Authors investigate "topological inflation" and its non-topological counterpart
- Simple setup includes Einstein gravity, electromagnetic field, and self-interacting scalar field
- Topological inflation has a non-topological equivalent
- Implications for cosmology and extreme conditions
- Model maintains unbroken U(1) symmetry, leading to boson stars with interesting properties
- Boson stars develop horizon under strong gravitational coupling
- Same phenomenon of inflation inside non-topological defects observed in black holes with scalar hair
- Discovery expands knowledge of black hole physics and interconnectedness between different areas of theoretical physics
- Provides insights into behavior of topological defects, inflationary processes, boson stars, and black holes with scalar hair
- Findings contribute to understanding of fundamental physics and have implications for future research in cosmology and astrophysics.

## Summary

In this paper titled "Inflation inside non-topological defects and scalar black holes," authors Y. Brihaye, F. Cônsole, and B. Hartmann investigate a phenomenon known as "topological inflation" and its non-topological counterpart. They explore a simple setup that includes Einstein gravity coupled minimally to an electromagnetic field and a self-interacting, complex valued scalar field. The authors demonstrate that topological inflation, which refers to the occurrence of inflation within the core of topological defects, also has a non-topological equivalent. This finding has significant implications for our understanding of cosmology and the behavior of physical systems in extreme conditions. The model used in this study maintains an unbroken U(1) symmetry, leading to the existence of globally regular solutions called boson stars. These boson stars exhibit interesting properties such as the development of a horizon under strong gravitational coupling. Furthermore, the authors extend their investigation to black holes with scalar hair and find that the same phenomenon of inflation inside non-topological defects occurs in these systems as well. This discovery expands our knowledge of black hole physics and highlights the interconnectedness between different areas of theoretical physics. Overall, this paper provides valuable insights into the behavior of topological defects, inflationary processes, and their counterparts in both boson stars and black holes with scalar hair. The findings contribute significantly to our understanding of fundamental physics and may have implications for future research in cosmology and astrophysics.