Violent Buckling is Good for Bars

Bars are unstable to a buckling instability which vertically heats the disk and in some cases forms a boxy/peanut shaped bulge. The buckling instability can be analyzed as an application of classical Euler buckling followed by the nonlinear gravitational Landau damping in the system. The energy of the buckling instability is dictated by the kinematic properties and geometry of the bar. High energy buckling happens quickly and encourages bar growth, while low energy buckling is a slower process that results in bar dissolution. Disks that undergo weak buckling remain stable to a second bar instability which contributes to an explanation of the observed bar fraction in the local Universe.