Comparing the Selmer group of a -adic representation and the Selmer group of the Tate dual of the representation
arXiv:1405.5289
Abstract
The main conjecture of Iwasawa theory is a conjecture on the relation between a Selmer group and a conjectural -adic -function. This conjectural -adic -function is expected to satisfy a conjectural functional equation in a certain sense. In view of the main conjecture and this conjectural functional equation, one would expect to have certain algebraic relationship between the Selmer group attached to a Galois representation and the Selmer group attached to the Tate twist of the dual of the Galois representation. It is precisely a component of this algebraic relationship that this paper aims to investigate. Namely, for a given "ordinary" -adic representation, we compare its Selmer group with the Selmer group of its Tate dual over an admissible -adic Lie extension, and show that the generalized Iwasawa -invariants associated to the Pontryagin dual of the two said Selmer groups are the same. We should mention that in proving the said equality of the -invariants, we do not assume the main conjecture nor the conjectural functional equation.
23 pages; will not be considered for formal publication. The main result of this article has been superceded by another writeup of the author: arXiv:1409.0942