Degeneration of the l-adic Eisenstein symbol and of the elliptic polylog
Abstract
Description
The main new result is the computation of the degeneration of l-adic Eisenstein classes at the cusps. This is done by relating it to the degeneration of the elliptic polylog.
These classes come from K-theory and their Hodge regulator can also be computed (see: Dirichlet motives via modula curves, on the K-theory server). This gives a new proof of a comparison conjecture of Bloch and Kato which was used in the proof of their Tamagawa number conjecture for the Riemann zeta-function.
The paper contains appendices on the definition of the classical and elliptic polylog, its degeneration and the comparison to Eisenstein classes.