In this paper we show that,
for each n ≧ 2, there is a unique, closed, compact, connected, simply connected
(n + 2)-manifold, Mn+2, admitting an action of Tn satisfying the following condition:
there are exactly n T1-stability groups T1,⋯,Tn with each F(Ti,Mn+2)
connected. In this case we have Tn≅T1 ×⋯ × Tn. Any other action (Tn,Mn+2),
Mn+2 simply connected, can be obtained from an action (Tn,Mn+2) by
equivariantly replacing copies of D4 × Tn−2 with copies of S3 × D2 × Tn−3. As an
application, we classify all actions of Tn on simply connected (n + 2)-manifolds for
n = 3,4.
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