Particle physics in cosmology
early universe, when the average energy density was very high. The processes of particle pair production, scattering and decay
influence the cosmology.
As a rough approximation, a particle scattering or decay process is important at a particular
cosmological epoch if its time scale is shorter than or similar to the time scale of the universe's expansion
. The latter quantity is where is the time-dependent 
Hubble parameter. This is roughly equal to the age of the universe
at that time.
For example, the
mean lifetime to decay of about 26 nanoseconds. This means that particle physics processes involving pion decay can be neglected until roughly that much time has passed since the Big Bang
.
Cosmological observations of phenomena such as the
beyond the Standard Model
.
Further reading
- Allday, Jonathan (2002). Quarks, Leptons and the Big Bang (Second ed.). ISBN 978-0-7503-0806-9.
- ISBN 3-540-43128-4.
- Branco, G. C., Shafi, Q., & Silva-Marcos, J. I. (2001). Recent developments in particle physics and cosmology. Dordrecht: ISBN 0-7923-7181-X
- Collins, P. D. B. (2007). Particle physics and cosmology. New York: ISBN 0-471-12071-5
- Kazakov, D. I., & Smadja, G. (2005). Particle physics and cosmology the interface. NATO science series, v. 188. Dordecht: ISBN 1-4020-3161-0
- "Science and technology - Cosmology and particle physics - What can the matter B?". OCLC 102695447.
External links
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