Lecture on Gauge Gravitation Theory. Gravity as a Higgs Field
  Gravitation theory is formulated as gauge theory on natural bundles with spontaneous symmetry breaking where gauge symmetries are general covariant transformations, gauge fields are general linear connections, and Higgs fields are pseudo-Riemannian metrics. 
G. Sardanashvily
math-ph gr-qc hep-th math.MP