The Ostmann conjecture asserts that the set 
of prime numbers is asymptotically additively indecomposable.
In the positive-integer
formulation, if 
each contain at least two elements, then
 |
where 
is the sumset and 
denotes symmetric
difference. Thus no finite modification of the primes is a nontrivial sumset
of two such sets. The problem is also called the inverse Goldbach problem. The assertion
requires eventual equality of sets, rather than agreement of their densities.
