Successive minima of projective toric varieties.

We compute the successive minima of the projective toric variety X-A associated to a finite set A subset of Z(.)(n) As a consequence of this computation and of the results of S.-W. Zhang on the distribution of small points, we derive estimates for the height of the subvariety X-A and of the A-resultant. These estimates allow us to obtain an arithmetic analogue of the Bezout-Kushnirenko's theorem concerning the number of solutions of a system of polynomial equations.