For a likelihood $p(y | \theta)$ and pdf $f(y)$:
Suppose that a likelihood is location invariant i.e.
$p(y | \theta) = f(y - \theta)$
Show that Jeffrey'sthe Jeffreys prior is of the form $p(θ) ∝ 1$.
I understand that we have to use the fisherFisher information to solve this, but am confused about the idea of location invariance.
Fisher = $\sqrt{(-E[d^2/(d\theta)^2 log (f(y - \theta))]}$$\sqrt{-E[d^2/(d\theta)^2 \log (f(y - \theta))]}$
which has to be proportional to $1$, but how do I use $f(y - \theta)$ in this equation for Fishers information?