The hunt for the equation of state of the universe

Monday 29  September, 2:30 pm, Curia II
Henk Hoekstra (CITA)
hoekstra@cita.utoronto.ca

The recent discovery that the dynamics of the universe are dominated
by some "dark energy" has created much excitement and puzzled
physicists. Although many different mechanisms have been proposed to
explain the results, current observational constraints to distinguish
between various models are limited. The key parameter to be determined
over the next decade is the equation of state w=P/rho, which relates
the pressure and the energy density of the dark energy.

I will discuss several techniques that can be used to constrain this
parameter. The type Ia supernovae and weak lensing measurements will
use data from the upcoming CFHT Legacy Survey, whereas the RCS2
cluster survey uses the abundance of massive clusters to constrain
cosmological parameters. To support the feasibility of these
techniques I will discuss some recent results obtained using data from
the RCS1 cluster survey.