field of algebraic topology, the homotopy groups of spheres describe how spheres of various dimensions can wrap around each other. They are examples of topological...
83 KB (8,124 words) - 04:10, 28 March 2025
map (see homotopy groups of spheres for this and more complicated examples of homotopy groups). Hence the torus is not homeomorphic to the sphere. In the...
20 KB (3,432 words) - 14:48, 25 May 2025
for n {\displaystyle n} sufficiently large. In particular, the homotopy groups of spheres π n + k ( S n ) {\displaystyle \pi _{n+k}(S^{n})} stabilize for...
4 KB (669 words) - 23:26, 17 August 2023
a branch of mathematics, a homotopy sphere is an n-manifold that is homotopy equivalent to the n-sphere. It thus has the same homotopy groups and the same...
2 KB (203 words) - 21:42, 4 February 2025
exotic spheres to singularities of complex manifolds. Kervaire, Michel A.; Milnor, John W. (1963). "Groups of homotopy spheres: I" (PDF). Annals of Mathematics...
29 KB (3,875 words) - 06:55, 9 May 2025
Steenrod algebra (section Connection to the Adams spectral sequence and the homotopy groups of spheres)
applications of the Steenrod algebra were calculations by Jean-Pierre Serre of some homotopy groups of spheres, using the compatibility of transgressive...
30 KB (5,577 words) - 03:49, 29 May 2025
Bott periodicity theorem (category Theorems in homotopy theory)
research, in particular in K-theory of stable complex vector bundles, as well as the stable homotopy groups of spheres. Bott periodicity can be formulated...
13 KB (1,836 words) - 07:04, 8 April 2025
{\displaystyle p} -local sphere spectrum. This is a key observation for studying stable homotopy groups of spheres using chromatic homotopy theory. Elliptic cohomology...
3 KB (405 words) - 21:48, 9 January 2024
Toda bracket (category Homotopy theory)
homotopy classes of maps, in particular on homotopy groups of spheres, named after Hiroshi Toda, who defined them and used them to compute homotopy groups...
7 KB (1,148 words) - 00:32, 20 June 2025
J-homomorphism (redirect from Stable fibre homotopy type)
J-homomorphism is a mapping from the homotopy groups of the special orthogonal groups to the homotopy groups of spheres. It was defined by George W. Whitehead (1942)...
8 KB (923 words) - 01:54, 4 April 2025
Generalized Poincaré conjecture (category Homotopy theory)
mathematical area of topology, the generalized Poincaré conjecture is a statement that a manifold that is a homotopy sphere is a sphere. More precisely...
11 KB (1,360 words) - 04:16, 14 July 2025
Zhouli Xu (category Fellows of the American Mathematical Society)
topology as a Professor of Mathematics at the University of California, Los Angeles, known for computations of homotopy groups of spheres. Xu earned both his...
8 KB (727 words) - 07:43, 28 May 2025
perfect field is isomorphic to the motivic stable homotopy group of spheres π0,0(S0,0) (see "A¹ homotopy theory"). Two fields are said to be Witt equivalent...
21 KB (3,163 words) - 18:06, 2 May 2025
Postnikov system (category Homotopy theory)
group. Adams spectral sequence Eilenberg–MacLane space CW complex Obstruction theory Stable homotopy theory Homotopy groups of spheres Higher group Hopf–Whitney...
20 KB (3,834 words) - 20:43, 19 June 2025
Eilenberg–MacLane space (category Homotopy theory)
contexts in algebraic topology, including computations of homotopy groups of spheres, definition of cohomology operations, and for having a strong connection...
20 KB (3,357 words) - 21:19, 19 June 2025
Frederick R. Cohen (category Fellows of the American Mathematical Society)
class groups. This was followed by a series of influential papers on unstable homotopy groups of spheres with John Moore and Joseph Neisendorfer. Late...
6 KB (488 words) - 04:41, 19 October 2024
Associated bundle Fibration Hopf bundle Classifying space Cofibration Homotopy groups of spheres Plus construction Whitehead theorem Weak equivalence Hurewicz...
4 KB (311 words) - 18:20, 28 June 2025
Spectrum (topology) (redirect from Stable homotopy category)
spectrum are its homotopy groups. These groups mirror the definition of the stable homotopy groups of spaces since the structure of the suspension maps...
22 KB (3,449 words) - 17:37, 16 May 2025
Homology (mathematics) (redirect from Homology groups)
{\displaystyle \pi _{1}(X)} . Higher homotopy groups are sometimes difficult to compute. For instance, the homotopy groups of spheres are poorly understood and are...
54 KB (8,218 words) - 16:31, 22 June 2025
Mark Mahowald (category University of Minnesota alumni)
is known for constructing one of the first known infinite families of elements in the stable homotopy groups of spheres by showing that the classes h...
6 KB (618 words) - 04:03, 28 March 2025
George W. Whitehead (category Members of the United States National Academy of Sciences)
first to systematically calculate the homotopy groups of spheres. He is also central to the study of Stable homotopy theory, in particular making concrete...
3 KB (252 words) - 02:36, 20 June 2024
(unstable) homotopy groups of spheres. In a 1957 paper he showed the first non-existence result for the Hopf invariant 1 problem. This period of his work...
3 KB (296 words) - 19:48, 15 November 2023
stack of (generalized) elliptic curves. This theory has relations to the theory of modular forms in number theory, the homotopy groups of spheres, and...
7 KB (996 words) - 15:30, 17 June 2025
Noetherian ring (section Noetherian group rings)
The sequence of ideals I0, I1, I2, etc., is an ascending chain that does not terminate. The ring of stable homotopy groups of spheres is not Noetherian...
20 KB (2,774 words) - 04:31, 7 July 2025
sphere Homology sphere – Topological manifold whose homology coincides with that of a sphere Homotopy groups of spheres – How spheres of various dimensions...
38 KB (7,348 words) - 04:00, 6 July 2025
Fields Medal (redirect from List of Fields medalists)
is the mathematical result of which Archimedes was reportedly most proud: Given a sphere and a circumscribed cylinder of the same height and diameter...
90 KB (4,942 words) - 13:45, 26 June 2025
higher-homotopy groups (k ≥ 4) are all finite abelian but otherwise follow no discernible pattern. For more discussion see homotopy groups of spheres. The...
28 KB (4,048 words) - 04:16, 9 May 2025
Douglas Ravenel (category Massachusetts Institute of Technology School of Science faculty)
the first of these two papers, the authors explore the stable homotopy groups of spheres by analyzing the E 2 {\displaystyle E^{2}} -term of the Adams–Novikov...
9 KB (921 words) - 12:33, 18 June 2025
spaces that are homotopy equivalent (or the stronger case of homeomorphic) have isomorphic fundamental groups. The fundamental group of a topological space...
53 KB (8,179 words) - 10:52, 14 July 2025
original on 2016-11-08.[self-published source?] "A Survey of Computations of Homotopy Groups of Spheres and Cobordisms" (PDF). p. 16. Archived (PDF) from the...
10 KB (1,906 words) - 02:09, 12 April 2025