A framework to a mass dimension one fermionic sigma model
  In this paper a mass dimension one fermionic sigma model, realized by the eigenspinors of the charge conjugation operator with dual helicity (Elko spinors), is developed. Such spinors are chosen as a specific realization of mass dimension one spinors, wherein the non-commutative fermionic feature is ruled by torsion. Moreover, we analyse Elko spinors as a source of matter in a background in expansion. Moreover, we analyse Elko spinors as a source of matter in a background in expansion and we have found that such kind of mass dimension one fermions can serve not only as dark matter but they also induce an effective cosmological constant. 
R. J. Bueno Rogerio, J. M. Hoff da Silva, S. H. Pereira, Roldao da   Rocha
hep-th gr-qc