The Dark Side Project: a quick science justification
Jim Annis, Oct 2003

A 5000 sq-degree survey of the Southern Galactic Cap
that overlaps a arcminte resolution map of the cosmic
microwave background allows us to probe dark energy
in several ways.

1) The growth function via clusters:
	 There will be cluster catalogs built three ways
		a) from the Sunyaev-Zeldovich map, deepest in z, shallowest in mass
		b) from the weak lensing shear map, shallowest in z
		c) from the galaxy magnitudes, deepest in mass
	   The first 2 catalogs will have their redshifts measured using
	   photometric redshifts of the 3rd catalog.
 
	These catalogs will allow a study of the evolution of the
	mass function via cluster number evolution along with mass
	calibrations derived from SZ, shear, and galaxy number
	estimates and cross checked from the cluster angular power spectrum.

	The mass function is sensitive primarily to power spectrum,
	secondarily to the growth and volume functions. Fortunately,
	the power spectrum is well constrained from CMB and galaxy distribution
	large scale structure power spectra. The growth function and volume
	element are both sensitive to the dark energy equation of state, w,
	and its time derivitive, w'.

2) The growth function via matter power spectrum
	Both the galaxy distribution and the weak lensing shear
	distribution measure the matter power spectrum (though
	the former is biased by the amount that galaxies don't
	trace mass). We should be able to pursue:
		a) weak lensing shear power spectra in photo-z bins
		b) galaxy power spectra in photo-z bins
		c) weak lensing shear cross correlations across photo-z bins
		  (the Jain and Taylor method), which has much promise.

3) The growth function via galaxy/cluster correlations with the
	Cosmic Microwave Background. The CMB data may be either SPT,
	the South Pole Telescope with it's 4000 sq-degree survey with
	1' resolution, or WMAP (in process) or Plank (2007? launch)
	data. The effects of large scale structure on the photons
	of the CMB are numerous, and there is a rich physics largely
	untouched by observation on the topic. The SZ is well measured,
	but only the first detections of ISW are coming out (led in part
	by Albert Stebbins of Fermilab); one can measure w in this way.
	It is probably true that the ISW effect is more sensitive to
	w' than it is to w; it shows the effect of dark energy from
	from tim 0 to the redshift observed, whereas angular diameter 
	and luminosity distance measures show the effect of dark energy
	from the redshift observed to now.