Additive uniform structure
of a topological skew-field
The uniform structure of its additive group. A base of neighbourhoods for the uniform structure of the commutative topological group of is formed by the sets of all pairs such that , where is an arbitrary neighbourhood of zero. A covering of a topological skew-field is uniform for the additive uniform structure if a covering of the type refining it can be found, where is an arbitrary neighbourhood of zero and . In particular, a base of the additive uniform structure of the real line is formed by all coverings by intervals of given fixed length. The real line is the completion of the field of rational numbers with respect to its additive uniform structure.
The uniform structure of the group , which is known as its additive uniform structure, is the product of the uniform structures of its factors . A base is constituted by all coverings by (open) spheres of a given fixed radius.
A uniform structure is also called a uniform topology. A base for a uniform structure is also called a uniformity. See also Uniform space.
|[a1]||J.R. Isbell, "Uniform spaces" , Amer. Math. Soc. (1964)|
Additive uniform structure. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Additive_uniform_structure&oldid=12073