Tests of Big Bang Cosmology (Review)
http://map.gsfc.nasa.gov/universe/bb_tests.html
The Big Bang Model is supported by a number of important
observations, each of which are described in more detail
on separate pages:
1. The expansion of the universe
http://map.gsfc.nasa.gov/universe/bb_tests_exp.html
Edwin Hubble's 1929 observation that galaxies were generally
receding from us provided the first clue that the Big Bang
theory might be right.
2. The abundance of the light elements H, He, Li
http://map.gsfc.nasa.gov/universe/bb_tests_ele.html
The Big Bang theory predicts that these light elements should
have been fused from protons and neutrons in the first few
minutes after the Big Bang.
3. The cosmic microwave background (CMB) radiation
http://map.gsfc.nasa.gov/universe/bb_tests_cmb.html
The early universe should have been very hot. The cosmic
microwave background radiation is the remnant heat leftover
from the Big Bang.
These three measurable signatures strongly support the notion
that the universe evolved from a dense, nearly featureless
hot gas, just as the Big Bang model predicts.
WMAP's Top Ten
1. NASA's Wilkinson Microwave Anisotropy Probe (WMAP) has
mapped the Cosmic Microwave Background (CMB) radiation (the
oldest light in the universe) and produced the first
fine-resolution (0.2 degree) full-sky map of the microwave sky
2. WMAP definitively determined the age of the universe to be
13.73 billion years old to within 1% (0.12 billion years) -as
recognized in the Guinness Book of World Records!
3. WMAP nailed down the curvature of space to within 1% of
"flat" Euclidean, improving on the precision of previous
award-winning measurements by over an order of magnitude
4. The CMB became the "premier baryometer" of the universe with
WMAP's precision determination that ordinary atoms (also called
baryons) make up only 4.6% of the universe (to within 0.1%)
5. WMAP's complete census of the universe finds that dark
matter (not made up of atoms) make up 23.3% (to within 1.3%)
6. WMAP's accuracy and precision determined that dark energy
makes up 72.1% of the universe (to within 1.5%), causing the
expansion rate of the universe to speed up. - "Lingering doubts
about the existence of dark energy and the composition of the
universe dissolved when the WMAP satellite took the most
detailed picture ever of the cosmic microwave background
(CMB)." - Science Magazine 2003, "Breakthrough of the Year"
article
7. WMAP has mapped the polarization of the microwave radiation
over the full sky and discovered that the universe was
reionized earlier than previously believed. - "WMAP scores on
large-scale structure. By measuring the polarization in the CMB
it is possible to look at the amplitude of the fluctuations of
density in the universe that produced the first galaxies. That
is a real breakthrough in our understanding of the origin of
structure." - ScienceWatch: "What's Hot in Physics", Simon
Mitton, Mar./Apr. 2008
8. WMAP has started to sort through the possibilities of what
transpired in the first trillionth of a trillionth of a second,
ruling out well-known textbook models for the first time.
9. The statistical properties of the CMB fluctuations measured
by WMAP appear "random"; however, there are several hints of
possible deviations from simple randomness that are still being
assessed. Significant deviations would be a very important
signature of new physics in the early universe.
10. WMAP has put the "precision" in "precision cosmology" by
reducing the allowed volume of cosmological parameters by a
factor of 30,000. The three most highly cited physics and
astronomy papers published in the new millennium are WMAP
scientific papers--- reflecting WMAP's enormous impact.
Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results
http://arxiv.org/abs/1212.5226
http://arxiv.org/pdf/1212.5226v3
We present cosmological parameter constraints based on the
final nine-year WMAP data, in conjunction with additional
cosmological data sets. The WMAP data alone, and in
combination, continue to be remarkably well fit by a
six-parameter LCDM model. When WMAP data are combined with
measurements of the high-l CMB anisotropy, the BAO scale, and
the Hubble constant, the densities, Omegabh2, Omegach2, and
Omega_L, are each determined to a precision of ~1.5%. The
amplitude of the primordial spectrum is measured to within
3%, and there is now evidence for a tilt in the primordial
spectrum at the 5sigma level, confirming the first detection
of tilt based on the five-year WMAP data. At the end of the
WMAP mission, the nine-year data decrease the allowable
volume of the six-dimensional LCDM parameter space by a
factor of 68,000 relative to pre-WMAP measurements. We
investigate a number of data combinations and show that their
LCDM parameter fits are consistent. New limits on deviations
from the six-parameter model are presented, for example: the
fractional contribution of tensor modes is limited to r<0.13
(95% CL); the spatial curvature parameter is limited to
-0.0027 (+0.0039/-0.0038); the summed mass of neutrinos is
<0.44 eV (95% CL); and the number of relativistic species is
found to be 3.84+/-0.40 when the full data are analyzed. The
joint constraint on Neff and the primordial helium abundance
agrees with the prediction of standard Big Bang
nucleosynthesis. We compare recent PLANCK measurements of the
Sunyaev-Zel'dovich effect with our seven-year measurements,
and show their mutual agreement. Our analysis of the
polarization pattern around temperature extrema is updated.
This confirms a fundamental prediction of the standard
cosmological model and provides a striking illustration of
acoustic oscillations and adiabatic initial conditions in the
early universe.
Planck 2013 results. I. Overview of products and scientific results
http://arxiv.org/abs/1303.5062
http://arxiv.org/pdf/1303.5062v1.pdf
The ESA's Planck satellite, dedicated to studying the early
universe, was launched on May 2009 and has been surveying the
microwave and submillimetre sky since August 2009. In March
2013, ESA and the Planck Collaboration publicly released the
initial cosmology products based on the first 15.5 months of
Planck operations, along with a set of scientific and
technical papers and a web-based explanatory supplement. This
paper describes the mission and its performance, and gives an
overview of the processing and analysis of the data, the
characteristics of the data, the main scientific results, and
the science data products and papers in the release.
Scientific results include robust support for the standard,
six parameter LCDM model of cosmology and improved
measurements for the parameters that define this model,
including a highly significant deviation from scale
invariance of the primordial power spectrum. The Planck
values for some of these parameters and others derived from
them are significantly different from those previously
determined. Several large scale anomalies in the CMB
temperature distribution detected earlier by WMAP are
confirmed with higher confidence. Planck sets new limits on
the number and mass of neutrinos, and has measured
gravitational lensing of CMB anisotropies at 25 sigma. Planck
finds no evidence for non-Gaussian statistics of the CMB
anisotropies. There is some tension between Planck and WMAP
results; this is evident in the power spectrum and results
for some of the cosmology parameters. In general, Planck
results agree well with results from the measurements of
baryon acoustic oscillations. Because the analysis of Planck
polarization data is not yet as mature as the analysis of
temperature data, polarization results are not released. We
do, however, illustrate the robust detection of the E-mode
polarization signal around CMB hot- and cold-spots.
Big Bang Acoustics: Movie and Sound Files
http://www.astro.virginia.edu/~dmw8f/sounds/cdromfiles/index.php
Frequently Asked Questions in Cosmology
http://www.astro.ucla.edu/~wright/cosmology_faq.html
sam.wormley@gmail.com
Tests of Big Bang Cosmology (Review)
http://map.gsfc.nasa.gov/universe/bb_tests.html
The Big Bang Model is supported by a number of important
observations, each of which are described in more detail
on separate pages:
1. The expansion of the universe
http://map.gsfc.nasa.gov/universe/bb_tests_exp.html
Edwin Hubble's 1929 observation that galaxies were generally
receding from us provided the first clue that the Big Bang
theory might be right.
2. The abundance of the light elements H, He, Li
http://map.gsfc.nasa.gov/universe/bb_tests_ele.html
The Big Bang theory predicts that these light elements should
have been fused from protons and neutrons in the first few
minutes after the Big Bang.
3. The cosmic microwave background (CMB) radiation
http://map.gsfc.nasa.gov/universe/bb_tests_cmb.html
The early universe should have been very hot. The cosmic
microwave background radiation is the remnant heat leftover
from the Big Bang.
These three measurable signatures strongly support the notion
that the universe evolved from a dense, nearly featureless
hot gas, just as the Big Bang model predicts.
WMAP's Top Ten
1. NASA's Wilkinson Microwave Anisotropy Probe (WMAP) has
mapped the Cosmic Microwave Background (CMB) radiation (the
oldest light in the universe) and produced the first
fine-resolution (0.2 degree) full-sky map of the microwave sky
2. WMAP definitively determined the age of the universe to be
13.73 billion years old to within 1% (0.12 billion years) -as
recognized in the Guinness Book of World Records!
3. WMAP nailed down the curvature of space to within 1% of
"flat" Euclidean, improving on the precision of previous
award-winning measurements by over an order of magnitude
4. The CMB became the "premier baryometer" of the universe with
WMAP's precision determination that ordinary atoms (also called
baryons) make up only 4.6% of the universe (to within 0.1%)
5. WMAP's complete census of the universe finds that dark
matter (not made up of atoms) make up 23.3% (to within 1.3%)
6. WMAP's accuracy and precision determined that dark energy
makes up 72.1% of the universe (to within 1.5%), causing the
expansion rate of the universe to speed up. - "Lingering doubts
about the existence of dark energy and the composition of the
universe dissolved when the WMAP satellite took the most
detailed picture ever of the cosmic microwave background
(CMB)." - Science Magazine 2003, "Breakthrough of the Year"
article
7. WMAP has mapped the polarization of the microwave radiation
over the full sky and discovered that the universe was
reionized earlier than previously believed. - "WMAP scores on
large-scale structure. By measuring the polarization in the CMB
it is possible to look at the amplitude of the fluctuations of
density in the universe that produced the first galaxies. That
is a real breakthrough in our understanding of the origin of
structure." - ScienceWatch: "What's Hot in Physics", Simon
Mitton, Mar./Apr. 2008
8. WMAP has started to sort through the possibilities of what
transpired in the first trillionth of a trillionth of a second,
ruling out well-known textbook models for the first time.
9. The statistical properties of the CMB fluctuations measured
by WMAP appear "random"; however, there are several hints of
possible deviations from simple randomness that are still being
assessed. Significant deviations would be a very important
signature of new physics in the early universe.
10. WMAP has put the "precision" in "precision cosmology" by
reducing the allowed volume of cosmological parameters by a
factor of 30,000. The three most highly cited physics and
astronomy papers published in the new millennium are WMAP
scientific papers--- reflecting WMAP's enormous impact.
Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results
http://arxiv.org/abs/1212.5226
http://arxiv.org/pdf/1212.5226v3
We present cosmological parameter constraints based on the
final nine-year WMAP data, in conjunction with additional
cosmological data sets. The WMAP data alone, and in
combination, continue to be remarkably well fit by a
six-parameter LCDM model. When WMAP data are combined with
measurements of the high-l CMB anisotropy, the BAO scale, and
the Hubble constant, the densities, Omegabh2, Omegach2, and
Omega_L, are each determined to a precision of ~1.5%. The
amplitude of the primordial spectrum is measured to within
3%, and there is now evidence for a tilt in the primordial
spectrum at the 5sigma level, confirming the first detection
of tilt based on the five-year WMAP data. At the end of the
WMAP mission, the nine-year data decrease the allowable
volume of the six-dimensional LCDM parameter space by a
factor of 68,000 relative to pre-WMAP measurements. We
investigate a number of data combinations and show that their
LCDM parameter fits are consistent. New limits on deviations
from the six-parameter model are presented, for example: the
fractional contribution of tensor modes is limited to r<0.13
(95% CL); the spatial curvature parameter is limited to
-0.0027 (+0.0039/-0.0038); the summed mass of neutrinos is
<0.44 eV (95% CL); and the number of relativistic species is
found to be 3.84+/-0.40 when the full data are analyzed. The
joint constraint on Neff and the primordial helium abundance
agrees with the prediction of standard Big Bang
nucleosynthesis. We compare recent PLANCK measurements of the
Sunyaev-Zel'dovich effect with our seven-year measurements,
and show their mutual agreement. Our analysis of the
polarization pattern around temperature extrema is updated.
This confirms a fundamental prediction of the standard
cosmological model and provides a striking illustration of
acoustic oscillations and adiabatic initial conditions in the
early universe.
Planck 2013 results. I. Overview of products and scientific results
http://arxiv.org/abs/1303.5062
http://arxiv.org/pdf/1303.5062v1.pdf
The ESA's Planck satellite, dedicated to studying the early
universe, was launched on May 2009 and has been surveying the
microwave and submillimetre sky since August 2009. In March
2013, ESA and the Planck Collaboration publicly released the
initial cosmology products based on the first 15.5 months of
Planck operations, along with a set of scientific and
technical papers and a web-based explanatory supplement. This
paper describes the mission and its performance, and gives an
overview of the processing and analysis of the data, the
characteristics of the data, the main scientific results, and
the science data products and papers in the release.
Scientific results include robust support for the standard,
six parameter LCDM model of cosmology and improved
measurements for the parameters that define this model,
including a highly significant deviation from scale
invariance of the primordial power spectrum. The Planck
values for some of these parameters and others derived from
them are significantly different from those previously
determined. Several large scale anomalies in the CMB
temperature distribution detected earlier by WMAP are
confirmed with higher confidence. Planck sets new limits on
the number and mass of neutrinos, and has measured
gravitational lensing of CMB anisotropies at 25 sigma. Planck
finds no evidence for non-Gaussian statistics of the CMB
anisotropies. There is some tension between Planck and WMAP
results; this is evident in the power spectrum and results
for some of the cosmology parameters. In general, Planck
results agree well with results from the measurements of
baryon acoustic oscillations. Because the analysis of Planck
polarization data is not yet as mature as the analysis of
temperature data, polarization results are not released. We
do, however, illustrate the robust detection of the E-mode
polarization signal around CMB hot- and cold-spots.
Big Bang Acoustics: Movie and Sound Files
http://www.astro.virginia.edu/~dmw8f/sounds/cdromfiles/index.php
Frequently Asked Questions in Cosmology
http://www.astro.ucla.edu/~wright/cosmology_faq.html
sam.wormley@gmail.com