# Linear Algebra

Very useful in calculating the partition function

Diagnolizing a matrix is a transformation using its eigen space.

$$\mathbf{A} \ast \mathbf{B} = \left(\mathbf{A}_{ij} \otimes \mathbf{B}_{ij}\right)_{ij}$$

Given a matrix $\mathbf X \to X_{m}^{\phantom{m}n}$, we can decompose it into three matrices $$… Tucker decomposition of a generalization of SVD to higher ranks To find the eigenvectors \mathbf x of a matrix \mathbf A, we construct the eigen equation$$ …