# Bulk QCD Thermodynamics and Sterile Neutrino Dark Matter

**Authors:** Kevork N. Abazajian, George M. Fuller  
**arXiv:** [astro-ph/0204293](https://arxiv.org/abs/astro-ph/0204293)  
**Date:** 2002-04-17  
**Summary page:** https://www.summarizepaper.com/en/arxiv-id/astro-ph--0204293v2/

## Key points

- Study focuses on relic densities of singlet (sterile) neutrinos in warm and cold dark matter scenarios
- Production of singlet neutrinos occurs at or near the QCD transition in most promising dark matter scenarios
- Accurate prediction of relic sterile neutrino mass density requires consideration of various processes simultaneously
- Processes include production, dilution, and disappearance of weak scatterers
- Calculating these processes contemporaneously leads to more precise predictions
- Determining mass and superweak mixing of singlet neutrinos through methods like radiative decay can provide insights into finite-temperature QCD transition
- Understanding their contribution to critical density enhances understanding of the transition
- Singlet neutrinos can serve as potential candidates for dark matter and are connected to fundamental aspects of particle physics such as QCD transition in early universe

## Summary

This study focuses on the relic densities of singlet (sterile) neutrinos in warm and cold dark matter scenarios, with a particular emphasis on their dependence on the characteristics of the QCD transition in the early universe. The researchers highlight that in the most promising dark matter scenarios, production of singlet neutrinos occurs at or near the QCD transition. To accurately predict the relic sterile neutrino mass density, it is essential to consider various processes simultaneously. These include production of singlets, their dilution and disappearance of weak scatterers. By calculating these processes contemporaneously more precise predictions can be obtained. The authors propose that determining the mass and superweak mixing of singlet neutrinos through methods such as radiative decay can provide valuable insights into finite-temperature QCD transition. Additionally, understanding their contribution to critical density further enhances our understanding of this transition. Overall, this study sheds light on how singlet neutrinos can serve as potential candidates for dark matter and highlights their connection to fundamental aspects of particle physics such as QCD transition in early universe.