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Eisenstein-Kronecker classes, integrality of critical values of Hecke $L$-functions and $p$-adic interpolation

Guido Kings, Johannes Sprang

TL;DR

The paper develops a geometric framework for critical values of Hecke $L$-functions over arbitrary totally complex fields by constructing equivariant coherent Eisenstein-Kronecker classes on CM abelian schemes using the completed Poincaré bundle. It then provides explicit computations of these classes in terms of generalized Eisenstein-Kronecker series and currents, connecting them to the de Rham polylogarithm and CM-type decompositions. The results yield integrality statements for regularized values $L(\chi,0)$ after division by explicit periods, and enable a $p$-adic interpolation measure in the ordinary case, generalizing prior CM-field constructions (Damerell, Shimura, Katz) to the broader CM setting. The work also introduces refined classes to manage integrality and develops a robust link between CM types, periods, and special $L$-values, with potential implications for Deligne-type conjectures and CM motives of rank one.

Abstract

We show that for an arbitrary totally complex number field $L$ the (regularized) critical $L$-values of algebraic Hecke characters of $L$ divided by certain periods are algebraic integers. This relies on a new construction of an equivariant coherent cohomology class with values in the completion of the Poincaré bundle on an abelian scheme $\cal{A}$. From this we obtain a cohomology class for the automorphism group of a CM abelian scheme $\cal{A}$ with values in some canonical bundles, which can be explicitly calculated in terms of Eisenstein-Kronecker series. As a further consequence, using an infinitesimal trivialization of the Poincaré bundle, we construct a $p$-adic measure interpolating the critical $L$-values in the ordinary case. This generalizes previous results for CM fields by Damerell, Shimura and Katz and settles the algebraicity and $p$-adic interpolation in the remaining open cases of critical values of Hecke $L$-functions.

Eisenstein-Kronecker classes, integrality of critical values of Hecke $L$-functions and $p$-adic interpolation

TL;DR

The paper develops a geometric framework for critical values of Hecke -functions over arbitrary totally complex fields by constructing equivariant coherent Eisenstein-Kronecker classes on CM abelian schemes using the completed Poincaré bundle. It then provides explicit computations of these classes in terms of generalized Eisenstein-Kronecker series and currents, connecting them to the de Rham polylogarithm and CM-type decompositions. The results yield integrality statements for regularized values after division by explicit periods, and enable a -adic interpolation measure in the ordinary case, generalizing prior CM-field constructions (Damerell, Shimura, Katz) to the broader CM setting. The work also introduces refined classes to manage integrality and develops a robust link between CM types, periods, and special -values, with potential implications for Deligne-type conjectures and CM motives of rank one.

Abstract

We show that for an arbitrary totally complex number field the (regularized) critical -values of algebraic Hecke characters of divided by certain periods are algebraic integers. This relies on a new construction of an equivariant coherent cohomology class with values in the completion of the Poincaré bundle on an abelian scheme . From this we obtain a cohomology class for the automorphism group of a CM abelian scheme with values in some canonical bundles, which can be explicitly calculated in terms of Eisenstein-Kronecker series. As a further consequence, using an infinitesimal trivialization of the Poincaré bundle, we construct a -adic measure interpolating the critical -values in the ordinary case. This generalizes previous results for CM fields by Damerell, Shimura and Katz and settles the algebraicity and -adic interpolation in the remaining open cases of critical values of Hecke -functions.

Paper Structure

This paper contains 38 sections, 68 theorems, 614 equations.

Key Result

Theorem 1

Let $\chi$ be a critical algebraic Hecke character of $L$ (see Section section:cm-types). Let $L(\chi,0)$ be the value of its $L$-function at $0$ and $\mathfrak{c}$ be an integral ideal in $L$ coprime to $\mathfrak{f}$. Then there is a number field $k$ with ring of integers $\mathscr{O}_k$ such that where $\Omega^{\chi}$ is an explicit product of powers of $2\pi i$ and certain periods of abelian v

Theorems & Definitions (187)

  • Theorem : Integrality of critical values, see Theorem \ref{['thm:special-values']}
  • Corollary : Weak Deligne conjecture, see Corollary \ref{['cor:deligne-conjecture']}
  • Theorem : $p$-adic interpolation, see Theorem \ref{['thm_p-adic-interpolation']}
  • Theorem : Eisenstein-Kronecker class, see Section \ref{['subsection:Eisenstein-Kronecker-class']}
  • Theorem 1.1: Decomposition SGA3
  • Definition 1.2
  • Remark 1.4
  • Proposition 1.5
  • proof
  • Definition 1.6
  • ...and 177 more