The cosmic microwave background is a window on the early universe
that is rich in information on the origin of structure in the universe
and the values of the fundamental cosmic parameters. Observational
cosmology as a precision science dates only from 1992, when the Cosmic
Background Explorer (COBE) detected fluctuations in the background.
George Smoot and John Mather shared the 2006 Nobel Prize for this
work. Although the fluctuations in the temperature of the background
amount to only 1 part in 105, they nevertheless have imprinted within
them information on the distribution of matter in the early universe.
The most-cited papers in the past decade are based on results from
the Wilkinson Microwave Anisotropy Probe (WMAP), the successor to COBE.
WMAP provided data of sufficient accuracy to discriminate between
cosmological models. This group of papers gives a value of 13.7
billion years for the age of the universe, and establishes that the
geometry is flat. The matter content of the universe is given as 4.4%
baryons (i.e., visible matter such as stars and galaxies), 22% dark
matter, and 73% dark energy. One paper draws attention to evidence
that the expansion of the universe is accelerating, thus reviving
Einstein’s concept of a cosmological constant, a speculation that
had been dismissed for decades.
The accelerating universe is the focus of attention for several of
the most-cited papers in the past two years. Three of the most-cited
papers showcase evidence for acceleration from the new sub-discipline,
supernova cosmology. One paper combines results from the Sloan Digital
Sky Survey and WMAP to refine even further the values of the
cosmological parameters. Papers in this two-year group chart the
emergence of a "consensus cosmology" in which the values of
the parameters are no longer a matter for debate because they are now
so tightly constrained. Other topics touched on are neutrino mass
(which is extremely small and could be zero), the linear growth of
structure in the universe from a redshift of 1000 to the present, and
the results from galaxy redshift surveys.
Methodology
To construct this database,
papers were extracted based on topic-supplied keywords for Cosmic Microwave Background Radiation. The keywords used were as follows:
cosmic microwave background
OR
CMB
The baseline time span for this database
is 1996-August 31, 2006. The resulting database contained 3,811 (10 years)
and 1,316 (2 years) papers; 5,027 authors; 58 countries; 313 journals; and
1,311 institutions.
Rankings
Once the database was in place,
it was used to generate the lists of top 20 papers (two- and ten-year
periods), authors, journals,
institutions, and nations, covering a time span of 1996-August 31,
2006 (fourth bimonthly, ten-year plus eight-month period).
The top 20 papers are ranked
according to total cites. Rankings for author, journal, institution,
and country are listed in three ways: according to total cites, total
papers, and total cites/paper. The paper thresholds and corresponding
percentages used to determine
scientist, institution, country, and journal rankings according to
total cites/paper, and total papers respectively are as follows:
| Entity: |
Scientists |
Institutions |
Countries |
Journals |
| Thresholds: |
29 |
15 |
24 |
18 |
| Percentage: |
1% |
10% |
50% |
10% |
Return to Menu
