Deuterium, a heavy isotope of hydrogen, was forged in the first minutes after the Big Bang. Its measured primordial abundance matches theoretical predictions with remarkable precision, providing powerful confirmation of the hot Big Bang model and constraining the baryon density of the universe.
The integrated Sachs–Wolfe (ISW) effect is a secondary anisotropy in the cosmic microwave background caused by the time variation of gravitational potentials along the line of sight. It arises when the universe’s expansion accelerates—most notably due to dark energy—and provides a unique probe of dark energy and the growth of cosmic structure.
Acoustic peaks are periodic ripples in the cosmic microwave background power spectrum, imprinted by sound waves in the early universe’s photon-baryon plasma. Their positions and heights reveal the geometry, composition, and evolution of the cosmos, making them a cornerstone of modern cosmology.
The quark–gluon plasma is the hottest, densest state of matter ever created, existing just after the Big Bang. This article explores its role in the universe’s evolution, from the Planck epoch to the formation of stars and galaxies, and how experiments like those at CERN recreate it.
CMB foregrounds are astrophysical emissions that contaminate measurements of the cosmic microwave background. Learn how scientists identify and subtract them to reveal the universe’s earliest light.
The density of the universe determines its geometry and fate. Current measurements show it is composed of 5% normal matter, 27% dark matter, and 68% dark energy, with a total density very close to the critical value. This article explores the cosmic density budget, the epochs that shaped the universe, and the evidence from missions like Planck and WMAP.
The tensor-to-scalar ratio (r) measures the relative strength of primordial gravitational waves versus density fluctuations in the early universe. It is a key observable for testing cosmic inflation and is probed through the B-mode polarization of the cosmic microwave background.
Quantum gravity is the theoretical bridge between general relativity and quantum mechanics, essential for understanding the Planck epoch — the earliest phase of the universe. This interactive guide explores the full cosmic timeline from the initial singularity to the present day, covering inflation, nucleosynthesis, recombination, and structure formation.
The first galaxies formed a few hundred million years after the Big Bang, ending the cosmic dark ages. Their observational signatures include ultraviolet continuum, Lyman-alpha emission, and nebular lines like H-alpha, which JWST is now detecting.
Explore the electroweak epoch, the Higgs mechanism, and the full cosmic timeline from the Planck epoch to structure formation. This definitive guide explains how the universe evolved, how particles gained mass, and what evidence supports our current model.
