Organized by:

Delphine Charbonneau (IAP, Paris, France),
Karim Benabed (IAP, Paris, France),
Yannick Mellier (IAP and Obs. de Paris, Paris, France),
Francis Bernardeau (CEA/SPhT Saclay  
and IAP associate, Paris, France),
Liping Fu (IAP, Paris, France),
Martin Kilbinger (IAP, Paris, France),
Jean Coupon (IAP, Paris, France)

Scientific Organizing Committee:

 M. Bartelmann (ITA, Heidelberg, Germany)
 F. Bernardeau (CEA/SPhT Saclay, France)
 R. Blandford (KIPAC , Standford, USA)
 F. Combes (Obs. Paris/LERMA, Paris, France)
 R. Ellis  (Caltech, Pasadena, USA)
 T. Hamana (NAOJ, Tokyo, Japan)
 B. Jain (U. Penn, Philadelphia, USA)
 A. Lewis (IoA, Cambridge, UK)
 A. Refregier (CEA/SAp, Saclay, France)
 G. Soucail (OMP, Toulouse, France)
 A. Taylor (ROE, Edinburgh, UK)
 J.-P. Uzan (IAP, Paris, France)
 L. Vigroux (IAP, France)
 L. Van Waerbeke (UBC, Vancouver, Canada)
 R. Webster (U. Melbourne, Victoria, Australia)

 Monday 2nd to Friday 6th July  2007

Dear colleagues, We are please to announce the XXIIIrd IAP colloquium that will held at IAP between July 2 and 6. Each year, The Institut d'Astrophysique de Paris organizes a colloquium on a different topic in cosmology and astrophysics 2007 will be the 65th anniversary of Prof. Bernard Fort and the 20th anniversary of the first papers on the discovery of giant arcs. To celebrate ths event, the XXIIIrd IAP colloquium will focus on gravitational distortion: rings, giant arcs, weak lensing and cosmic shear, distortion of CMB anisotropy maps.

Review speakers:
R. Blandford (introductory), S. White (Conference summary),
P. Schneider,  A. Taylor, H. Hoekstra, M. Bartelmann,
D. Spergel, J.-P. Kneib, A. Lewis, J.-P. Uzan, R. Ellis

Invited speakers:
A. Challinor, M. Takada, K. Kuijken, B. Sanders, O. Cappe , R. Teyssier

The conference fees are 250 euros.

A colored image of the first giant arc discovered with the Canada-France-Hawaii Telescope (CFHT) in the distant cluster of galaxies Abell 370. This image is composed of a B and a R exposures obtained at CFHT using the RCA CCD mounted at the prime focus of the telescope. Copyright: CFHT.