matrix, vector and tensor operators

1. matrix multiplication

AB=C$$AB=C$$

ref:
Matrix multiplication - Wikipedia
https://en.wikipedia.org/wiki/Matrix_multiplication

2. inner product (dot product)

Algebraic definition

a⋅b=∑i=1naibi$$\mathit{a}\mathbf{\cdot }\mathit{b}=\sum _{i=1}^n{a}_i{b}_i$$

ref:
Dot product - Wikipedia
https://en.wikipedia.org/wiki/Dot_product

3. outer product

u⊗v=uvT$$\mathit{u}\mathbf{\otimes }\mathit{v}\mathbf{=}\mathit{u}{\mathit{v}}^{\mathit{T}}$$

ref:
Outer product - Wikipedia
https://en.wikipedia.org/wiki/Outer_product

4. Hadamard product (matrices)

ref:
Hadamard product (matrices) - Wikipedia
https://en.wikipedia.org/wiki/Hadamard_product_(matrices)

00000

ref:
List of mathematical symbols by subject - Wikipedia
https://en.wikipedia.org/wiki/List_of_mathematical_symbols_by_subject
Multilinear algebra - Wikipedia
https://en.wikipedia.org/wiki/Multilinear_algebra