cohomology

complex geometry

# Contents

## Overview

Hodge theory is centered around fine structure seen at the level of (complex, rational and integer) cohomologies (and motives) of Kähler manifolds, based on the study of harmonic forms on them, and the Hodge theorem: Hodge decomposition, Hard Lefschetz theorem, pure Hodge structures, mixed Hodge structures, variations of Hodge structure, Hodge to de Rham spectral sequence, periods… This basic setup is however by now vastly generalized.

The nomenclature “nonabelian”/”noncommutative” Hodge theory may be confusing - to clarify:

Nonabelian Hodge theory refers to the generalization of classical Hodge theory for commutative spaces from abelian coefficients to nonabelian coefficients.

Noncommutative Hodge theory refers to the generalization of classical Hodge theory from commutative geometry (e.g. algebraic varieties) to noncommutative geometry (e.g. dg-categories – see also the page on noncommutative algebraic geometry). The coefficients in noncommutative Hodge theory are abelian.

Ultimately, the goal is to develop a Hodge theory for noncommutative spaces with nonabelian coefficients.

## References

### Contributors

The main historical contributors to Hodge theory include William Hodge, P. Griffiths, Alexander Grothendieck, Pierre Deligne. More recently a noncommutative generalization and refinement of Hodge theory is emerging in the work of M. Kontsevich and collaborators (D. Kaledin, L. Katzarkov, Tony Pantev…) with precursors in the works of Carlos Simpson, Mikio Sato, C. Hertling and others. Another very interesting and complex picture is developing for a number of years in works of Goncharov.

### General

• Bertin, Demailly, Illusie, Chris Peters, Introduction to Hodge theory AMS (1996)

• Claire Voisin, Hodge theory and the topology of complex Kähler and complex projective manifolds (survey, pdf)

• Claire Voisin, Hodge theory and complex algebraic geometry I,II, Cambridge Stud. in Adv. Math. 76, 77

• Mark Green, Claire Voisin, Jacob Murre, Algebraic cycles and Hodge theory Lecture Notes in Mathematics, 1594 (1993)

• P. Griffiths, Periods of integrals on algebraic manifolds I,II,III, Amer. J. Math. 90, 568–626, 808–865 (1968) ; Publ. Math. de l’IHÉS 38, 228–296 (1970) numdam

• M. Saito, Mixed Hodge modules, Publ. R.I.M.S. Kyoto Univ. 26 (1990) pp. 221–333.

• L. Katzarkov, M. Kontsevich, Tony Pantev, Hodge theoretic aspects of mirror symmetry, arxiv/0806.0107 Proc. of Symposia in Pure Math. 78 (2008), “From Hodge theory to integrability and TQFT: $tt^*$-geometry”, eds. Ron Y. Donagi and Katrin Wendland, 87-174

• D. Kaledin, Cartier isomorphism and Hodge theory in the non-commutative case, Arithmetic geometry, 537–562, Clay Math. Proc. 8, Amer. Math. Soc. 2009, arxiv/0708.1574

• D. Kaledin, Tokyo lectures “Homological methods in non-commutative geometry”, pdf, TeX

• Claus Hertling, Christian Sevenheck, Twistor structures, $tt^*$-geometry and singularity theory, arxiv/0807.2199

• C. Hertling, C. Sabbah, Examples of non-commutative Hodge structure (v1 title: Fourier-Laplace transform of flat unitary connections and TERP structures), arxiv/0912.2754

• A. B. Goncharov, Hodge correlators, arxiv/0803.0297, Hodge correlators II, arxiv/0807.4855

• C. T. C. Wall, Periods of integrals and topology of algebraic varieties, jstor

### Relation to motives

Discussion of Hodge theory in relation to motives is in

Revised on June 9, 2013 16:08:42 by Zoran Škoda (109.227.43.65)