University of Wisconsin-Madison Skip navigationDepartment of Physics Search Site Map UW Home


UW Home Page


This Week at Physics

Physics Events this

Colloquia & Seminars

Physics Department

Astronomy Colloquia

Chaos & Complex
Systems Seminars

College of Engineering

High Energy Seminars

Medical Physics

NPAC Forums

Physics Department

"Physics Today"

Physics/ECE/NE 922

R. G. Herb Materials
Physics Seminars

String Theory Seminars

Theory/Phenomenology Seminars

Wonders of Physics

Department of Physics
Colloquia & Seminars

Physics Department Colloquium
Big Bang Nucleosynthesis as a Probe of Cosmology and Particle Physics
Time: 4:00 PM
Place: 2241 Chamberlin Hall (coffee at 330 pm)
Speaker: Gary Steigman, Ohio State
Abstract: Briefly, during its early evolution, the Universe was a cosmic nuclear reactor. The expansion and cooling of the Universe limited this epoch to the first few minutes, allowing time for the synthesis in astrophysically interesting abundances of only the lightest nuclides D, 3He, 4He, 7Li. For big bang nucleosynthesis (BBN) in the standard models of cosmology and particle physics (SBBN), the SBBN-predicted abundances only depend on the baryon density parameter, the ratio (by number) of baryons (nucleons) to photons. The predicted and observed abundances of the relic light elements are reviewed, testing the internal consistency of SBBN. The consistency of BBN is further explored by comparing the values of the cosmological parameters inferred from primordial nucleosynthesis for models with non-standard early Universe expansion rates with those derived from studies of the cosmic background radiation, which provides a snapshot of the Universe some 400 thousand years after BBN has ended.
Host: Ramsey-Musolf
Download this video

Do you have questions? Oh yes you do!
Contact (access restricted)

  $Id:,v 1.1 2011/10/25 17:40:19 rader Exp $