Invariants of tensors

In mathematics, in the fields of multilinear algebra and representation theory, invariants of tensors are coefficients of the characteristic polynomial of the tensor A:

where ${\displaystyle \mathbf {E} }$ is the identity tensor and ${\displaystyle \lambda \in \mathbb {C} }$ is the polynomial's indeterminate (it is important to bear in mind that a polynomial's indeterminate ${\displaystyle \lambda }$ may also be a non-scalar as long as power, scaling and adding make sense for it, e.g., ${\displaystyle p(\mathbf {A} )}$ is legitimate, and in fact, quite useful).

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