Preheating in Bubble Collisions
  In a landscape with metastable minima, the bubbles will inevitably nucleate.
We show that during the bubbles collide, due to the dramatically oscillating of
the field at the collision region, the energy deposited in the bubble walls can
be efficiently released by the explosive production of the particles. In this
sense, the collision of bubbles is actually highly inelastic. The cosmological
implications of this result are discussed.
