Normal Vector Fields on Manifolds1
نویسنده
چکیده
2. Statement of results. We will be concerned with cohomology groups having as coefficients the integers, Z, or the integers mod 2, Z2. If Mn is an w-dimensional differentiable manifold, then WíElH'ÍM", Z2) denotes the îth Stiefel-Whitney class of the tangent bundle, and WiGH^M", Z2) denotes the ith dual Stiefel-Whitney class. Our first theorem gives a necessary condition for the existence of a normal vector field.
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تاریخ انتشار 2010