BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Dark Energy -- where are the natural explanations? - Ed Copeland (
 Nottingham)
DTSTART:20080220T141500Z
DTEND:20080220T153000Z
UID:TALK9968@talks.cam.ac.uk
CONTACT:Daniel Wesley
DESCRIPTION:Evidence from a number of astronomical observations appear to 
 indicate that over 95% of the energy density making up our Universe is dar
 k\, we can not see it but can only infer its existence from observations o
 f things we can see\, namely the remaining 5% or so that make up the baryo
 ns. The 95% is split up into 25% dark matter which behaves like ordinary m
 atter in that it acts like a pressureless dust\, and 70% dark energy\, an 
 unusual form of matter which has a negative pressure. This dark energy is 
 causing the Universe to accelerate today. In the talk we will discuss the 
 evidence for dark energy\, the theoretical proposals there are to explain 
 what it is and the possible ways we may in the future be able to discrimin
 ate between the various proposals. Along the way\, we will come across the
  cosmological constant\, dynamical models of dark energy and modifications
  of Einstein's gravity -- all in all we will see there really is currently
  no natural explanation for this fantastic observation.\n\n
LOCATION:MR2\, Centre for Mathematical Sciences
END:VEVENT
END:VCALENDAR