BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:How isotropic is the Universe? - Daniela Saadeh (UCL)
DTSTART:20170123T130000Z
DTEND:20170123T140000Z
UID:TALK70092@talks.cam.ac.uk
CONTACT:47984
DESCRIPTION:A fundamental assumption of the standard model of cosmology is
  that the large-scale Universe is isotropic. Because of its centrality\, i
 t is essential to test this assumption. Breaking isotropy leads to Bianchi
  cosmologies\, a set of solutions to the Einstein field equations of which
  only the subset describing rotating universes was previously tested again
 st data. In this talk\, I present a general test of isotropy considering\,
  for the first time\, all the degrees of freedom of anisotropic expansion.
  We analyse cosmic microwave background data from Planck\, carrying out th
 e first joint analysis of temperature and polarization data for this purpo
 se. We also show that improved constraints on anisotropy may be obtained b
 y extending the likelihood to high ell. For the vector mode (associated wi
 th rotating universes)\, we obtain a limit on the anisotropic expansion th
 at is an order of magnitude tighter than previous Planck results using the
  CMB temperature only. We recover upper limits for all the other modes\, w
 ith the weakest one arising from the regular tensor modes. We disfavour an
 isotropic expansion of the Universe with odds of 121\,000:1 against.
LOCATION:CMS\, Pav. B\, CTC Common Room (B1.19) [Potter Room]
END:VEVENT
END:VCALENDAR