Description |
Abstract: Among other things, the cyclotomic units are remarkable in the sense that they induce (via the Kummer map) a compatible system of Galois cohomology classes that are crucial to the proof of the Main Iwasawa conjecture. The goal of this lecture is to present a way (suitable to generalizations) to approach the construction of these classes via the study of congruences between Eisenstein series and cusp forms of various levels and weights. |