description Baryon acoustic oscillations Overview
Baryon acoustic oscillations are density fluctuations in the early universe, imprinted as characteristic patterns in the distribution of matter now observable across vast cosmic distances.
help Baryon acoustic oscillations FAQ
Why are baryon acoustic oscillations called a standard ruler?
BAO leave a preferred separation scale in the distribution of galaxies, often described as about 150 megaparsecs in comoving distance. Cosmologists use that scale to compare distances at different redshifts and measure cosmic expansion.
What caused baryon acoustic oscillations in the early universe?
Before recombination, photons and ordinary matter behaved like a coupled hot plasma where pressure waves could travel. When the cosmic microwave background was released around 380,000 years after the Big Bang, those waves left an imprint in matter clustering.
Which surveys use BAO measurements?
BAO has been measured with galaxy surveys such as SDSS, BOSS, eBOSS, and DESI. DESI uses millions of galaxy and quasar redshifts to refine distance measurements across cosmic time.
How are BAO different from the cosmic microwave background?
The CMB is a direct map of early-universe temperature fluctuations, while BAO is measured later through the positions of galaxies and other tracers. They are related because both come from early density waves in the same young universe.
explore Explore More
Similar to Baryon acoustic oscillations
See all arrow_forward
Reviews & Comments
Write a Review
Be the first to review
Share your thoughts with the community and help others make better decisions.
