© 2013

Hypoelliptic Laplacian and Bott–Chern Cohomology

A Theorem of Riemann–Roch–Grothendieck in Complex Geometry


Part of the Progress in Mathematics book series (PM, volume 305)

Table of contents

  1. Front Matter
    Pages i-xv
  2. Jean-Michel Bismut
    Pages 1-13
  3. Jean-Michel Bismut
    Pages 15-20
  4. Jean-Michel Bismut
    Pages 21-39
  5. Jean-Michel Bismut
    Pages 41-61
  6. Jean-Michel Bismut
    Pages 63-81
  7. Jean-Michel Bismut
    Pages 91-112
  8. Jean-Michel Bismut
    Pages 113-121
  9. Jean-Michel Bismut
    Pages 159-164
  10. Back Matter
    Pages 191-203

About this book


The book provides the proof of a complex geometric version of a well-known result in algebraic geometry: the theorem of Riemann–Roch–Grothendieck for proper submersions. It gives an equality of cohomology classes in Bott–Chern cohomology, which is a refinement for complex manifolds of de Rham cohomology. When the manifolds are Kähler, our main result is known. A proof can be given using the elliptic Hodge theory of the fibres, its deformation via Quillen's superconnections, and a version in families of the 'fantastic cancellations' of McKean–Singer in local index theory. In the general case, this approach breaks down because the cancellations do not occur any more. One tool used in the book is a deformation of the Hodge theory of the fibres to a hypoelliptic Hodge theory, in such a way that the relevant cohomological information is preserved, and 'fantastic cancellations' do occur for the deformation. The deformed hypoelliptic Laplacian acts on the total space of the relative  tangent bundle of the fibres. While the original hypoelliptic Laplacian discovered by the author can be described in terms of the harmonic oscillator along the tangent bundle and of the geodesic flow, here, the harmonic oscillator has to be replaced by a quartic oscillator. Another idea developed in the book is that while classical elliptic Hodge theory is based on the Hermitian product on forms, the hypoelliptic theory involves a Hermitian pairing which is a mild modification of intersection pairing. Probabilistic considerations play an important role, either as a motivation of some constructions, or in the proofs themselves.


Riemann-Roch theorems and Chern characters analytic torsion determinants and determinant bundles heat and other parabolic equation methods hypoelliptic equations index theory and related fixed point theorems

Authors and affiliations

  1. 1., Département de MathématiqueUniversité Paris-SudOrsayFrance

About the authors

Jean-Michel Bismut is Professor of Mathematics at Université Paris-Sud (Orsay) and a member of the Académie des Sciences. Starting with a background in probability, he has worked extensively on index theory. With Gillet, Soulé, and Lebeau, he contributed to the proof of a theorem of Riemann–Roch–Grothendieck in Arakelov geometry. More recently, he has developed a theory of the hypoelliptic Laplacian, a family of operators that deforms the classical Laplacian, and provides a link between spectral theory and dynamical systems.

Bibliographic information