The mean-value of a product of shifted multiplicative functions and the average number of points of elliptic curves

In this paper, we consider the mean value of the product of two real valued multiplicative functions with shifted arguments. The functions F and G under consideration are close to two nicely behaved functions A and B  , such that the average value of A(n−h)B(n)A(n−h)B(n) over any arithmetic progression is only dependent on the common difference of the progression. We use this method on the problem of finding mean value of NK(N)/ϕ(N)NK(N)/ϕ(N), where NK(N)/ϕ(N)log⁡NNK(N)/ϕ(N)log⁡N is the expected number of primes such that a random elliptic curve over rationals has N points when reduced over those primes.