Borsuk-Ulam theorem

Call a continuous map $f:S^{m}\\to S^{n}$ antipode preserving if $f(-x)=-f(x)$ for all $x\\in S^{m}$ .

Theorem: There exists no continuous map $f:S^{n}\\to S^{n-1}$ which is antipode preserving for $n>0$ .

Some interesting consequences of this theorem have real-world applications. For example, this theorem implies that at any time there exists antipodal points on the surface of the earth which have exactly the same barometric pressure and temperature.

It is also interesting to note a corollary to this theorem which states that no subset of $\\mathbb{R}^{n}$ is homeomorphic to $S^{n}$ .

单词	BorsukUlamTheorem
释义	Borsuk-Ulam theorem Call a continuous map $f:S^{m}\\to S^{n}$ antipode preserving if $f(-x)=-f(x)$ for all $x\\in S^{m}$ . Theorem: There exists no continuous map $f:S^{n}\\to S^{n-1}$ which is antipode preserving for $n>0$ . Some interesting consequences of this theorem have real-world applications. For example, this theorem implies that at any time there exists antipodal points on the surface of the earth which have exactly the same barometric pressure and temperature. It is also interesting to note a corollary to this theorem which states that no subset of $\\mathbb{R}^{n}$ is homeomorphic to $S^{n}$ .
随便看	EisensteinCriterion Eisenstein criterion EisensteinCriterionInTermsOfDivisorTheory Eisenstein criterion in terms of divisor theory EisensteinIntegers Eisenstein integers EisensteinPrime Eisenstein prime EIsIrrational e is irrational e is irrational EIsIrrational1 EIsNotAQuadraticIrrational e is not a quadratic irrational EIsTranscendental e is transcendental EkelandsVariationalPrinciple Ekeland’s variational principle ElementarilyEquivalent elementarily equivalent ElementaryAbelianGroup elementary abelian group ElementaryEmbedding elementary embedding ElementaryFunction