Published online by Cambridge University Press: 01 July 2009
The combined conjecture of Lang-Bogomolov for tori gives an accurate description of the set of those points x of a given subvariety  of
 of  , that with respect to the height are “very close” to a given subgroup Γ of finite rank of
, that with respect to the height are “very close” to a given subgroup Γ of finite rank of  . Thanks to work of Laurent, Poonen and Bogomolov, this conjecture has been proved in a more precise form.
. Thanks to work of Laurent, Poonen and Bogomolov, this conjecture has been proved in a more precise form.
In this paper we prove, for certain special classes of varieties  , effective versions of the Lang-Bogomolov conjecture, giving explicit upper bounds for the heights and degrees of the points x under consideration. The main feature of our results is that the points we consider do not have to lie in a prescribed number field. Our main tools are Baker-type logarithmic forms estimates and Bogomolov-type estimates for the number of points on the variety
, effective versions of the Lang-Bogomolov conjecture, giving explicit upper bounds for the heights and degrees of the points x under consideration. The main feature of our results is that the points we consider do not have to lie in a prescribed number field. Our main tools are Baker-type logarithmic forms estimates and Bogomolov-type estimates for the number of points on the variety  with very small height.
 with very small height.
 , Internat. Math. Res. Notices  7 (1995), 333–347.CrossRefGoogle Scholar
, Internat. Math. Res. Notices  7 (1995), 333–347.CrossRefGoogle Scholar . Monatsh. Math. to appear.Google Scholar
. Monatsh. Math. to appear.Google Scholar . In Number Theory (Paris, 1993–1994), London Math. Soc. Lecture Note Ser. 235 (Cambridge University Press, 1996), 157–187.CrossRefGoogle Scholar
. In Number Theory (Paris, 1993–1994), London Math. Soc. Lecture Note Ser. 235 (Cambridge University Press, 1996), 157–187.CrossRefGoogle Scholar