%0 Journal Article %T On some modular representations of the Borel subgroup of GL_2(Q_p) %A Laurent Berger %J Mathematics %D 2008 %I arXiv %R 10.1112/S0010437X09004345 %X Colmez has given a recipe to associate a smooth modular representation Omega(W) of the Borel subgroup of GL_2(Q_p) to a F_p^bar-representation W of Gal(Qp^bar/Qp) by using Fontaine's theory of (phi,Gamma)-modules. We compute Omega(W) explicitly and we prove that if W is irreducible and dim(W)=2, then Omega(W) is the restriction to the Borel subgroup of GL_2(Q_p) of the supersingular representation associated to W in Breuil's correspondence. %U http://arxiv.org/abs/0810.5083v5