# Ultrarelativistic Gas with Zero Chemical Potential

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## Abstract

**:**

## 1. Introduction

## 2. Photon Gas

## 3. Ultrarelativistic Ideal Gas

## 4. From Classical to Quantum

## 5. The Connection of an Evaporating Gas with the Cavity Radiation

## 6. Physical Considerations

## 7. Concluding Remarks

## Author Contributions

## Funding

## Acknowledgments

## Conflicts of Interest

## Appendix A

## References

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**Figure 1.**Spectral energy density for a Planck gas (red); a Wien gas (blue), and the resulting extrapolation of boson-like gas made of classical neutrinos with spin degeneracy $\omega =2$ (blue), and the resulting boson-like gas made of classical neutrino pairs with spin degeneracy $\omega =1$ (green) and $\omega =3$ (orange).

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**MDPI and ACS Style**

Mata-Pacheco, D.; Ares de Parga, G.; Angulo-Brown, F.
Ultrarelativistic Gas with Zero Chemical Potential. *Symmetry* **2019**, *11*, 249.
https://doi.org/10.3390/sym11020249

**AMA Style**

Mata-Pacheco D, Ares de Parga G, Angulo-Brown F.
Ultrarelativistic Gas with Zero Chemical Potential. *Symmetry*. 2019; 11(2):249.
https://doi.org/10.3390/sym11020249

**Chicago/Turabian Style**

Mata-Pacheco, Daniel, Gonzalo Ares de Parga, and Fernando Angulo-Brown.
2019. "Ultrarelativistic Gas with Zero Chemical Potential" *Symmetry* 11, no. 2: 249.
https://doi.org/10.3390/sym11020249