On Consistence of Material Coupling in a GL(3,R) Gauge Formulation of   Gravity
  A covariant scheme for material coupling with $GL(N,R)$ gauge formulation of gravity is studied. We revisit a known idea of a Yang-Mills type construction, where quadratical power of cosmological constant have to be considered in consistence with vacuum Einstein's gravity. Then, matter coupling with gravity is introduced and some constraints on fields and background appear. Finally, exploring the N=3 case we elucidate that introduction of auxiliary fields decreases the number of these constraints. 
Rolando Gaitan (Theoretical Physics Group of Physics Departament of   Carabobo's University, Valencia, Venezuela)