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Whitehead products and vector-fields on spheres

Published online by Cambridge University Press:  24 October 2008

I. M. James
Affiliation:
The Mathematical Institute10 Parks RoadOxford

Extract

In the theory of vector-spaces an ordered, ortho-normal set of r vectors is called an r-frame. Let Sn denote the unit sphere in euclidean (n+ 1)-space, where n ≥ 1. By an r-field on Sn is meant a continuous function which assigns to each point of Sn an r-frame in the tangent space at that point. If q < r we obtain a q-field from an r-field by suppressing the first rq vectors of each r-frame. Certainly Sn admits a 0-field, and does not admit an (n+ 1)-field, since the tangent space is n-dimensional. An n-field on Sn is called a parallelism. Notice that an (n − 1)-field on Sn can always be extended to an n-field, since spheres are orientable. The problem is to determine the greatest value of r such that Sn admits an r-field.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1957

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References

REFERENCES

(1)Eckmann, B.Stetige Lösungen linearer Gleichungssysteme. Comment, math. helvet. 15 (1942), 318–39.CrossRefGoogle Scholar
(2)Eckmann, B.Beweis des Satzes von Hurwitz–Radon. Comment, math. helvet. 15 (1942), 358–66.CrossRefGoogle Scholar
(3)Hilton, P. J. and Whitehead, J. H. C.Note on the Whitehead product. Ann. Math., Princeton, 58 (1953), 429–42.CrossRefGoogle Scholar
(4)Hopf, H.Ein topologischer Beitrag zur reellen Algebra. Comment. math. helvet. 13 (1940), 219–39.CrossRefGoogle Scholar
(5)James, I. M.On the iterated suspension. Quart. J. Math. (2), 5 (1954), 110.CrossRefGoogle Scholar
(6)James, I. M.On the suspension sequence. Ann. Math., Princeton, 65 (1957), 74107.CrossRefGoogle Scholar
(7)James, I. M.Cross-section of Stiefel manifolds. Proc. Lond. Math. Soc. (3) (in the Press).Google Scholar
(8)James, I. M. and Whitehead, J. H. C.The homotopy theory of sphere-bundles over spheres (I). Proc. Lond. Math. Soc. (3) 4 (1954), 196218.CrossRefGoogle Scholar
(9)Serre, J.-P.Homologie singulière des espaces fibrés. Ann. Math., Princeton, 54 (1951), 425505.CrossRefGoogle Scholar
(10)Serre, J.-P.Cohomologie modulo 2 des complexes d'Eilenberg-MacLane. Comment. math. helvet. 27 (1953), 198232.CrossRefGoogle Scholar
(11)Steenrod, N. E.The topology of fibre bundles (Princeton, 1951).CrossRefGoogle Scholar
(12)Steenrod, N. E. and Whitehead, J. H. C.Vector fields on the n-sphere. Proc. Nat. Acad. Sci., Wash., 37 (1951), 5863.CrossRefGoogle ScholarPubMed
(13)Toda, H.Calcul de groupes d'homotopie des sphères. C.R. Acad. Sci., Paris, 240 (1955), 147–9.Google Scholar
(14)Toda, H.Le produit de Whitehead et l'invariant de Hopf. C.R. Acad. Sci., Paris, 241 (1955), 849–50.Google Scholar
(15)Whitehead, G. W.A generalization of the Hopf invariant. Ann. Math., Princeton, 51 (1950), 192237.CrossRefGoogle Scholar