Title:
Radial Mixing in the Milky Way Disk: Constraints on Spiral Structure.

Abstract:
We have recently identified a previously unknown radial migration mechanism
resulting from the resonance overlap of multiple patterns in galactic disks
(Minchev & Famaey 2010, Minchev, Famaey et al. 2010). This new mechanism
is much more efficient than mixing by transient spirals and must exist in all
barred galaxies, such as our own Milky Way. The consequences of this
are a strong
flattening in the metallicity gradient in the disk, an extended disk profile,
and the formation of a thick disk component, taking place in only a couple of
Gyr. This timescale is drastically shorter than previously expected
and thus puts strong constraints on the longevity, strength and pattern speeds
of the Galactic bar and Spiral Structure. I will discuss the implications
resonance overlap induced migration can have on observations of Spiral
Structure in the Galaxy.