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Incoming links: Charles L. Bennett
Charles L. Bennett Created 2026-10-18 Updated 2026-11-05
Charles L. Bennett led the final nine-year WMAP analysis of cosmic microwave background maps. The work combined sky temperature and polarization measurements while modeling Galactic foreground emission and the response of the observing beams.
The angular patterns constrain cosmological parameters through a physical model of the early Universe. The paper compared the resulting Lambda-CDM model with independent observations, including baryon acoustic oscillations. Its quoted cosmic age and expansion rate are fitted consequences of those combined data and assumptions, rather than direct readings from a single sky image.[ref]
Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Final Maps and Results by C. L. Bennett and others. Abstract: beam treatment, foreground separation, nine-year maps and combined cosmological constraints
Portrait of Charles L. Bennett
. Johns Hopkins University (JHU); individual photographer not separately named in the File. File dated 2015. Creative Commons Attribution-Share Alike 4.0 International., via Wikimedia Commons. Source.
COBE DMR sky anisotropy experiment 2026-10-18
In 1992 the COBE DMR team, including George F. Smoot and Charles L. Bennett, used radiometer antennas to compare antenna temperatures between sky directions apart at , and , with two nearly independent channels per frequency. Repeated sky coverage supported least-squares solution map reconstruction.[ref]
The analysis fitted magnetic response and removed the assumed kinematic angular dipole and its second-order Doppler effect contribution. Channel sums retained sky structure; channel differences estimated noise. Cross-channel correlations, different frequency maps and Milky Way latitude cuts tested the interpretation. Residual large-angle structure supported Cosmic microwave background anisotropy; Galactic contamination particularly limited the cosmic microwave background quadrupole. Brightness fluctuations alone were not sufficient evidence of primordial structure.[ref]
Structure in the COBE Differential Microwave Radiometer First-Year Maps by George F. Smoot and others. §§2–3.1, p.L2: controls, motion subtraction, Table1
The two differences serve different purposes. Comparing two sky directions measures angular variation. Comparing two independently calibrated receiver maps observing the same sky tests noise and consistency. A common sky signal cancels in the latter comparison if their antenna beam patterns and response scales match; a systematic error shared by both channels need not cancel. Separating observer motion, local emission and intrinsic Cosmic microwave background anisotropy requires these additional tests.