We introduce the
-adjoined
Gauss map. We use it to express the Gaussian maximum likelihood degree as a
product of two invariants. As an application of our product formula, we classify all
projective curves of Gaussian maximum likelihood degree 1. We also provide a
formula for the
generic Gaussian maximum likelihood degree of a projective variety
in
terms of its polar classes. The renowned polar class formula for generic Euclidean
distance degree is a special case of our formula.
Keywords
algebraic statistics, rational MLE, maximum likelihood
degree