The conference will focus on the formation and evolution of galaxy disks starting with a session dedicated to the Milky Way and Local Group galaxies which are critical objects for our understanding of the disk galaxy picture. This session will present a review of the properties of the disks of the Milky Way, M31, M33, and other nearby galaxies, their correlations with the bulge and halo components, and the effects of the interaction with the galaxy satellites.

Star formation in disks is a subject on which we can expect dramatic new results from multi-wavelength observations from space-based observatories (e.g. HST, GALEX, Spitzer, Chandra, XMM). By 2007 the Schmidt-Kennicutt laws should have been explored on local (and not just disk-averaged) spatial scales throughout disks of a large sample of nearby galaxies. We should have constraints on disk growth timescales and radial dependence from measured star formation rates. To complement this topic we will include some talks on chemical evolution.

Studying the structure of galaxy disks is the starting point to address the formation of lenticular and spiral galaxies. Most of nearby stellar disks are radially truncated in their outskirts. These outer edges could either trace the maximum angular momentum during the galaxy formation epoch or be associated with global star formation thresholds. New insights in the fields are expected from the analysis of structural properties of disk at high redshift from on-going surveys (e.g. GEMS, DEEP, and COSMOS) which will unveil how disks evolve over time.

Accretion and merging events are keys in the formation of disks. Many authors have emphasized that quiescent accretion dominates the evolution of small galaxies, while more violent events like major mergers are more important for big galaxies. This issue has been emphasized repeatedly by the galaxy formation simulators that drive the state of the art, and many progresses have been made by improved resolution and inclusion of more realistic physics in simulations of disks.

Secular evolution is a subject that is making rapid progress in the observational and theoretical aspects. On the observational side new results on the systematic properties of pseudobulges such as stellar populations and star formation timescales are expected in a few years. On the theoretical side, we plan to cover different topics of this active research area such as the pseudobulges formation out of disk bars, evolution of bars, and mechanisms responsible for the disk heating process.

In connection with the evolution of structural disk properties, there are a number of observables which that will be mature by 2007 (stellar mass, rotation velocity, size, star formation rates, color gradients). Other important subtopics are bars at intermediate redshift, disks and environment (i.e. what happens to their star formation rates, sizes, colors when we throw them into groups/clusters). There is ample observational evidence for these processes at z < 1, and some limited insights up to z=3. This session complements the “archeological picture” we are getting from disks in the Local Group.

One of the results that was crystallized since of our last Vatican meeting, Galaxy Disks and Disk Galaxies, was the realization that we do not understand how to make pure disk galaxies in a cold dark matter, hierarchically clustering Universe. This issue is related to other two hot topics of the investigation of the disk formation via numerical simulations, namely the angular momentum crisis and dark halo concentration crisis. Since then, these problems have grown still sharper. They are some of the most interested and pressing problems that we could address at the proposed symposium.