I am looking for results on the equation $$ax^n-by^m=1 \tag 1 $$ where $\gcd(m,n)=1$ and $a,b,n,m$ are constants.
I found literature for $ax^n-by^n=1$ (R. A. Mollin, D. T. Walker) but couldn't find anything on equation $(1)$.
The closest I got is Pillai's conjecture which is a generalization of Catalan's conjecture.
Does $ax^n-by^m=1$ has infinite solution? If it does how do we find them?
Please provide related literature/reference if possible.