Suppose I have $m$ samples drawn from a Gaussian in $\mathbb{R}^n$, and need the inverse of the sample covariance $\Sigma_m^{-1}$ to be $\epsilon$$\varepsilon$-close to true inverse covariance $\Sigma^{-1}$ (in expectation or (preferably) with high probability):
$$||\Sigma^{-1}_m-\Sigma^{-1}|| \le \epsilon ||\Sigma^{-1}||$$$$\|\Sigma^{-1}_m-\Sigma^{-1}\| \le \varepsilon \|\Sigma^{-1}\|$$
For the sample covariance it is known that $$||\Sigma_m-\Sigma|| \le \epsilon ||\Sigma||$$$$\|\Sigma_m-\Sigma\| \le \varepsilon \|\Sigma\|$$ can be achieved with $r=\text{tr}\ \Sigma/||\Sigma||$$r=\operatorname{tr} \Sigma/\|\Sigma\|$ (the intrinsic dimension) $$m \approx \epsilon^{-2} r$$$$m \approx \varepsilon^{-2} r$$
I wonder if there is anything similar for the inverse covariance?