GENERAL SPHERICAL SYMMETRY SOLUTION TO EINSTEIN EQUATIONS AND NEWTONIAN GRAVITY MODIFICATION AT SMALL LENGTH SCALE.

In this paper, we first we present a general spherical symmetry solution, independent of any coordinate condition, to the Einstein equations. By using this solution, we obtain different cases in different coordinate conditions, such as Schwarzschild solution, Fock solution, which have different forms of f(r). Then, we obtain a modified formula with respect to f(r) of the Newtonian gravity. This formula may describe the gravity at small length scale. [ABSTRACT FROM AUTHOR]