Remarks on the uniqueness of weak solutions of the incompressible Navier-Stokes equations

This article studies the uniqueness of the weak solution of the incompressible Navier-Stokes Equations in the 3-dimensional case. Here, the investigation is provided using two different approaches. The first (the main) result is obtained for given functions possessing a certain smoothness using the new approach. The second result is without the complementary conditions but is, in some sense, the "local" result investigated by another approach. In addition, here the solvability and uniqueness of the weak solutions to auxiliary problems lead out from the main problem are investigated.