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Section 23.2 Terminology and notation

n-dimensional complex vector

a vector with n complex components; i.e. a vector v=(v1,v2,…,vn) where each component vj is a complex number

complex scalar multiplication

a rule for associating to a complex number k and an object v another object kv

complex vector space

a collection of mathematical objects, along with appropriate conceptions of vector addition and complex scalar multiplication, that satisfies the Vector space axioms (where we interpret scalar to mean complex number instead of just real number)

Here follows the notation we will use for some common complex vector space examples.

Cn

the collection of all n-dimensional complex vectors

Mm×n(C)

the vector space of all m×n matrices with entries that are complex numbers; as in the real case before, when m=n we sometimes just write Mn(C) to mean the vector space of all square n×n complex matrices

P(C)

the vector space of all polynomials with complex coefficients in a single complex variable

Pn(C)

the vector space of all polynomials with complex coefficients in a single complex variable that have degree n or less

Finally, we will see in Subsection 23.3.4 that every complex vector space can also be considered as a real vector space. So in some of our notation we will occasionally need to make it clear which point of view is being used.

SpanRS

the collection of all possible linear combinations of the vectors in set S, where only real scalars are allowed as the coefficients

SpanCS

the collection of all possible linear combinations of the vectors in set S, where complex scalars are allowed as the coefficients

dimRV

the dimension of the real vector space V

dimCV

the dimension of the complex vector space V