Geons of Galileons
  We suggest that galileon theories should have an additional self-coupling of the fields to the trace of their own energy-momentum tensor. We explore the classical features of one such model, in flat 4D spacetime, with emphasis on solutions that are scalar analogues of gravitational geons. We discuss the stability of these scalar geons, and some of their possible signatures, including shock fronts. 
Thomas L. Curtright and David B. Fairlie
hep-th astro-ph.CO astro-ph.GA