Is the Universe Homogeneous and Isotropic?
A pretty interesting article about the structure of the Universe - whether it is actually homogeneous and isotropic. These assumptions were at one point held as probably true, but the more we learn, the less likely they become.
The most interesting part says that the inhomogeneity might arise from “gargantuan ripples in the density of matter across the universe, known as baryon acoustic oscillations.”
A paper submitted to arxiv.org at the end of last month by Juan Garcıa-Bellido and Troels Haugbolle, The Radial BAO scale and Cosmic Shear, a new observable for Inhomogeneous Cosmologies, goes into detail about these things. They have the idea that the dimming of distant supernova, as described in the above article, is caused by spatial gradients. They then describe an observable that can be used by future surveys in the determination of the structure of the Universe.
Is the Universe homogeneous and isotropic? I think not!
This entry was posted on Wednesday, November 26th, 2008 at 1:06 am and is filed under Astrophysics. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
