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Aspen Center for Physics 
Winter 2007 workshop

"Clusters of galaxies as cosmological probes" 

Feb 12-16, 2007
Aspen, Colorado


The workshop will focus on observational
and theoretical aspects of galaxy clusters with specific
focus on their use as cosmological probes. 

The workshop will be held from monday until friday (Feb 12-16) 
and will consist of 20-30 min talks in morning and afternoon
sessions with a break from 11am until 5pm. 
Participation will be limited to ~70 people. Practical
details and information about lodging and other arrangements
will follow in the subsequent mailings. 

If you are interested in attending, please fill out 
the attached form and send it to Andrey Kravtsov
andrey@oddjob.uchicago.edu (by Oct 15, 2006).

The fees and lodging costs at the Aspen Meadows hotel from last winter
are given below (the information about the cost for the winter of 2007
will be send in subsequent mailings). Please note that lodging fees
include full breakfast and dinner meals monday through friday.

Conference Fees: Registration - $300.00
                  Housing Per Night (incl. breakfast and dinner)
                    - $220.00 single occupancy
                    - $141.50 per person double occupancy



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Scientific Organizing Committee: 

Andrey Kravtsov (The University of Chicago)
Christine Jones (CfA/SAO, Harvard)
Tim McKay (University of Michigan)
Joe Mohr (University of Illinois)
John Carlstrom (The University of Chicago)
Alexey Vikhlinin (CfA/SAO, Harvard)

Contact information: 

The primary contact for the organizing committee is 
Andrey Kravtsov
Department of Astronomy, The University of Chicago
5640 S. Ellis Ave.
Chicago, IL 60637

email: andrey@oddjob.uchicago.edu
fax: 773-702-6645

Scientific Rationale and Focus
----------------------------------

Clusters of galaxies are powerful and in many ways
unique probes of cosmology. Their abundance and spatial 
distribution are very sensitive to key cosmological parameters: 
the normalization of the primordial power spectrum, the density of 
matter in the Universe, and properties of the vacuum. 
Evolution of the cluster abundance reveals the growth of structure, 
potentially distinguishing between different models
for the apparent acceleration of the Universe, such as dark energy
and modified gravity. 

Internal properties of clusters can constrain the mass fraction
of baryons in the Universe, the Hubble constant, and, via the 
angular size-redshift test, the contributions of matter and
dark energy to the total energy density budget of the Universe.  

A new generation of large X-ray, optical, and Sunyaev-Zel'dovich
Effect (SZ) cluster surveys (SDSS, SPT, ACT, DES) are producing
or will produce cluster samples of tens of thousands of objects. 
These datasets have the statistical power to 
constrain cosmological parameters with unprecedented precision.
To realize the promise of these surveys, it is critical 
to understand how cluster observables relate to mass, and to 
determine the evolution and scatter in these relations. In addition, 
theoretical and observational biases in cluster selection need to be
very well understood. 

In 2006, we expect several significant results from the first large
cluster surveys, such as the 400 square degree X-ray survey, the SDSS
(optical and weak lensing), and initial results from the first 
blind SZ surveys (SZA, AMI, and APEX-SZ). At
the same time, we have witnessed many theoretical advances in
understanding the properties of galaxy clusters and effects of galaxy
formation and AGN feedback are being actively explored using a new
generation of high-resolution cosmological simulations.

Winter 2007 would therefore be particularly timely for a cluster
workshop, which will focus on the current observational results and
theoretical advances. The goal is to define strategies for the use of
clusters as powerful cosmological probes in ways which take full
advantage of the statistical power of the observational samples.

The specific topics of the workshop will include: 

* Cosmology with cluster surveys: 
* Detection and selection of clusters
* Mass distribution in galaxy clusters: 
* Properties of the intracluster medium. X-ray view: 
* Properties of the intracluster medium. SZ view: 
* Baryon content of clusters: 
* Cluster scaling relations and their evolution. 
* Near future strategies and directions for using 
  clusters as cosmological probes