In this thesis we first show, at the level of formal expansions, that

any compact manifold can be the sphere at infinity of an asymptot-

ically conical gradient expanding Ricci soliton. We then prove the

existence of a smooth blowdown limit for any Ricci-DeTurck flow on

R n , starting from possibly non-smooth data which is asymptotically

conical and sufficiently L ∞ -close to an expanding soliton on R n . Fur-

thermore, this blowdown flow is an expanding Ricci-DeTurck soliton

coming out of the asymptotic cone of the initial data.