%0 Journal Article %T Cyclotomic Units and Class Groups in Z_p extensions of real abelian fields %A Filippo A. E. Nuccio %J Mathematics %D 2008 %I arXiv %X For a real abelian field and for an odd prime p splitting in the field, we study a map between the p-parts of the class group and of the quotient of units modulo Cyclotomic Units, respectively, along the cyclotomic Z_p-extension of the field. We determine the kernel and the cokernel of this map assuming Greenberg's conjecture on the vanishing of the lambda-invariant of the extension. %U http://arxiv.org/abs/0812.0784v1