Left over from the big bang beginning of the universe
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Left Over from the Big Bang: Tracing the Universe's Origins
Cosmic Microwave Background Radiation (CMBR)
The Cosmic Microwave Background Radiation (CMBR) is the most significant remnant from the Big Bang, providing a snapshot of the universe when it was just 300,000 years old. This radiation, now observed as a nearly isotropic 2.73 K blackbody spectrum, carries imprints of the early universe's conditions and has been pivotal in shaping our understanding of cosmology5 6. The CMBR's small anisotropies reveal information about the universe's basic cosmological parameters, such as its total energy density and curvature, supporting the cold dark matter models in a flat universe5.
Hydrogen Ionization and the Early Universe
The fraction of ionized hydrogen left over from the Big Bang is crucial for understanding the formation of the first stars and quasar black holes. Observations of distant quasars indicate that the intergalactic medium (IGM) had not been completely ionized about one billion years after the Big Bang, with a significant fraction of neutral hydrogen still present1. This suggests a complex ionization history with a second peak in the mean ionization, influenced by the emergence of high-energy photons from early cosmic objects1.
Cold Dark Matter and Structure Formation
Cold dark matter (CDM) is another critical component left over from the Big Bang. It consists of slowly moving elementary particles that originated from quantum fluctuations shortly after the Big Bang. These particles played a fundamental role in the development of the universe's structure, seeding the formation of galaxies, clusters, and superclusters3. The CDM paradigm is supported by various observations, including the anisotropy of the CMBR and measurements of the Hubble constant3.
Cosmic Background Radiation and Polarization
Recent advancements, such as the Wilkinson Microwave Anisotropy Probe (WMAP), have provided detailed maps of the CMBR's polarization. These maps offer insights into the universe's state when it was just 10^-35 seconds old, testing the standard cosmological model's robustness4. The polarization data helps refine our understanding of the early universe's conditions and the processes that led to the current cosmic structure4.
Conclusion
The remnants of the Big Bang, particularly the CMBR and cold dark matter, are fundamental to our understanding of the universe's origins and evolution. These elements provide critical evidence for the conditions and processes that shaped the cosmos, from the formation of the first stars and galaxies to the large-scale structure we observe today. Through ongoing observations and advancements in technology, we continue to unravel the mysteries left over from the Big Bang, deepening our comprehension of the universe's beginnings.
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Most relevant research papers on this topic
A large neutral fraction of cosmic hydrogen a billion years after the Big Bang
A billion years after the Big Bang, the intergalactic medium had a neutral hydrogen fraction of tens of percent, suggesting a second peak in the mean ionization history of the Universe.
Highly CitedCold Dark Matter
The cold dark matter paradigm, based on slow-moving elementary particles left over from the Big Bang, is being tested by a flood of observations, including the Hubble constant and cosmic background radiation anisotropy.
Highly CitedA flat Universe from high-resolution maps of the cosmic microwave background radiation
High-resolution maps of the cosmic microwave background radiation reveal a flat, euclidean Universe, supporting cold dark matter models in standard inflationary models.
Highly CitedThe CMBR and the Seeds of Galaxies
The Cosmic Microwave Background Radiation (CMBR) provides clues about the origin and early evolution of the Universe, and its spectrum rules out non-gravitational models of structure formation.
Limits on Small Scale Variations in the Cosmic Background Radiation
The cosmic background radiation may exhibit small angular size variations due to density inhomogeneities, impacting our understanding of galaxy origins and their magnetic fields.
Dark matter and gravitational waves from a dark big bang
The Dark Big Bang scenario, which creates dark matter and potentially dark radiation, is consistent with structure formation and the CMB constraints, and may lead to striking gravity wave signatures.
The Ekpyrotic universe: Colliding branes and the origin of the hot big bang
The hot big bang universe is produced by the collision of a brane with a bounding orbifold plane, addressing cosmological horizon, flatness, and monopole problems without invoking superluminal expansion.
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