Numerical Investigations of Oscillons in 2 Dimensions
  Oscillons, extremely long-living localized oscillations of a scalar field, are studied in theories with quartic and sine-Gordon potentials in two spatial dimensions. We present qualitative results concentrating largely on a study in frequency space via Fourier analysis of oscillations. Oscillations take place at a fundamental frequency just below the threshold for the production of radiation, with exponentially suppressed harmonics. The time evolution of the oscillation frequency points indirectly to a life time of at least 10 million oscillations. We study also elliptical perturbations of the oscillon, which are shown to decay. We finish by presenting results for boosted and collided oscillons, which point to a surprising persistence and soliton-like behaviour. 
Mark Hindmarsh and Petja Salmi