Solving $T(n)=4T(n/4) +(n/\log n)^2$.
When I looked at the question I thought that this can be solved by the 3rd case of the master theorem since $f(n)$ is polynomially larger than $n^{\log_ba }=n.$ But someone said that this is not polynomially larger since it has $(\log n)^2$ in the denominator.
Then I tried the substitution method. I have found an upper bound of $n^2$ and a lower bound of $n\log n$ but I am unable to proceed any further.
I want a theta bound.