Nondegenerate 2-forms exist on even-dimensional manifolds
94261
why is there no non-degenerate 2-forms on 4-sphere?
139922
Is it known what the necessary and sufficient conditions are for the existence of a "3+1 split" (by means of a foliation) of a (Lorentzian) manifold?
82230
Proof of equivalence of conformal and complex structures on a Riemann surface.
38950
On the uniqueness of the Riemann-Christoffel tensor
151637
How do we prove that this set is not manifold?
11319
Is $M=\{(x,|x|): x \in (-1, 1)\}$ not a differentiable manifold?
132586
Solvability of Poisson's equation for $p$-forms directly from Hodge decomposition
154009
Closed, simply connected manifolds which are not spheres
21198
Proving that the general linear group is a differentiable manifold
71791
Smooth structure of embedded submanifolds
55089
Basis of the space of vector fields on smooth manifolds
119579
$S^2 \times S^2$ is diffeomophic to $G_2(\mathbb{R}^4)$
80418
The "Easiest" non-smoothable manifold
109027
example of a non differentiable manifold
19453
Invariance of domain for manifold
74024
Higher dimensional equivalent of complex numbers
78624
CW complexes and manifolds