[Triumf-seminars] TRIUMF Theory Seminar today at 13:00

[TRIUMF Seminars]

Date/Time: Tue 2012-05-08 at 13:00

Location:  Theory Room         

Speaker:   Kenneth Nollett (ANL)

Title:     Light nuclei, the Universe, and everything:  New insights from primordial nucleosynthesis

Abstract: The earliest time in the history of the universe that is clearly
probed by observations is the period from about one second to about
ten minutes after the big bang, when the initial chemical composition
of the universe was determined in the process known as big-bang
nucleosynthesis (BBN).  This was a much simpler time than today, so
the physical processes that produced measurable amounts of only
hydrogen, helium, and lithium can be easily modeled. By studying the
isotopic compositions of the light elements and comparing against the
model, we learn about both the overall structure of the universe and
the fundamental particles that populate it.  I will review the theory
and observational evidence regarding BBN, emphasising the role of
nuclear physics.  I will discuss limits from BBN and the cosmic
microwave background on the early expansion history of the universe
and the corresponding constraints on neutrino-like particles.  If time
permits, I will also discuss the surprisingly loose observational
constraints on large-scale inhomogeneities in the primordial matter
distribution.  Throughout the discussion I will emphasize the
important role of the physics of light nuclei in formulating BBN as a
high-precision theory.




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