Oscillons in Higher-Derivative Effective Field Theories
  We investigate the existence and behavior of oscillons in theories in which
higher derivative terms are present in the Lagrangian, such as galileons. Such
theories have emerged in a broad range of settings, from higher-dimensional
models, to massive gravity, to models for late-time cosmological acceleration.
By focusing on the simplest example---massive galileon effective field
theories---we demonstrate that higher derivative terms can lead to the
existence of completely new oscillons (quasi-breathers). We illustrate our
techniques in the artificially simple case of 1 + 1 dimensions, and then
present the complete analysis valid in 2 + 1 and 3 + 1 dimensions, exploring
precisely how these new solutions are supported entirely by the non-linearities
of the quartic galileon. These objects have the novel peculiarity that they are
of the differentiability class $C^1$.
