Hamiltonian vortices and reconnection in magnetized plasmas are
investigated
analytically and numerically using a two-fluid model. The equations are
written in
the Lagrangian form of three fields that are advected with different velocities.
This
system can be considered as a generalization and extension of the two-dimensional
Euler equation for an ordinary fluid. It is pointed out that these equations
allow
solutions in the form of singular current-vortex filaments, drift-Alfvén
vortices and
magnetic islands, and admit collisionless magnetic reconnection where magnetic
flux is converted into electron momentum and ion vorticity.