Vector spaces

1 minute read

Published:

Ring

아래와 같은 2개의 연산을 만족하는 집합

(R,+) is a commutative group, i.e.,
associative addition
commutative addition
additive zero and inverse

(R,*) is a semi-group, i.e., a*(b*c) = (a*b)*c

Vector space

Linear vector space X consist of

  • a set of elements, called vectors
  • a set of scalars in a field F
  • two operators, called vector addition and scalar multiplication

Normed Vector space

Normed vector spaces with a real-valued function, || ||, such as
Nonnegativity
Strict positivity
Homogeneity
Triangle inequality

Banach space

A complete normed vector space
어떤 space 내부 혹은 경계에 빠진 점이 없는 거리 공간

A normed vector space X is complete if every Cauchy sequence from X has a limit in X

A sequence {xn} in a normed space is said to be a Cauchy sequence if xn - nm -> 0 as n,m -> infty; i.e., given epsilon>0, there is an integer N such that xn - xm <epsilon for n,m >N

Hilbert space

A Banach space with an inner product < , >
Symmetry
Additivity
Homogeneity
Strict positivity

각 space 의 중요성 및 쓰임에 대해…