Thursday, March 06, 2008

WMAP: five-year data released

It's been two years since the publication of the WMAP three-year data. As some of the readers know, 3+2=5 so the only sensible thing that the WMAP team can publish right now are the five-year data.
WMAP 5: main page
WMAP 5: papers
WMAP 5: Phil Plait
WMAP 5: Sean Carroll
Theoretical physicists and non-experimenters will primarily care about the cosmological interpretation.

Don't expect a revolution here. Some numbers got a little bit more accurate, following Lord Kelvin's prescription for the completion of science. For example,
  • the Hubble constant is 70.1 +- 1.3 km/s per Mpc
  • the relative density of dark energy is 72.1 +- 1.5 percent
  • the relative density of dark matter is 23.3 +- 1.3 percent
  • the relative density of baryonic matter is 4.6 +- 0.2 percent
  • the age of the Universe is 13.73 +- 0.12 billion years
  • the global mean temperature dropped to 2.725 K by now (outside the urban heat islands such as stars, plus minus the fractions of the degree from the image above), confirming worries about global cooling ;-)
  • the recombination occurred on 375,900th (+- 3,100) birthday

Interestingly enough, the team can exclude the existence of very massive neutrino species: the total sum of the neutrino masses is below 0.61 eV, at the 95% confidence level. Entertainingly enough, they have a non-particle-physics measurement of the number of neutrino species: it is 4.4 +- 1.5 which makes the value 3 tolerable. ;-)

Tensor-to-scalar ratio is below 20% at 95% confidence level, making theories with gravity waves and with the spectral index above one disfavored.

1 comment:

  1. see for better understanding: the big bang symmetrical splitting black hole in fractal shape and the small copy of splitting black holes inside Carina and Eagle nebulae.