Abstract
Let
ℳ
0
n
{\mathcal{M}_{0}^{n}}
be the class of closed, simply connected, non-negatively curved Riemannian n-manifolds admitting an isometric, effective, isotropy-maximal torus action. We prove that if
M
∈
ℳ
0
n
{M\in\mathcal{M}_{0}^{n}}
, then M is equivariantly diffeomorphic to the free, linear quotient by a torus of a product of spheres of dimensions greater than or equal to 3. As a special case, we then prove the Maximal Symmetry Rank Conjecture for all
M
∈
ℳ
0
n
{M\in\mathcal{M}_{0}^{n}}
. Finally, we show
the Maximal Symmetry Rank Conjecture for simply connected, non-negatively curved manifolds holds for dimensions less than or equal to 9 without additional assumptions on the torus action.