# Large time limit and local L^2-index theorems for families

#### Autoren: Sara Azzali, Sebastian Goette, Thomas Schick (2015)

We compute explicitly, and without any extra regularity assumptions, the large time limit of the fibrewise heat operator for Bismut-Lott type superconnections in the $L^2$-setting. This is motivated by index theory on certain non-compact spaces (families of manifolds with cocompact group action) where the convergence of the heat operator at large time implies refined $L^2$-index formulas. As applications, we prove a local $L^2$-index theorem for families of signature operators and an $L^2$-Bismut-Lott theorem, expressing the Becker-Gottlieb transfer of flat bundles in terms of Kamber-Tandeur classes. With slightly stronger regularity we obtain the respective refined versions: we construct $L^2$-eta forms and $L^2$-torsion forms as transgression forms.

Zeitschrift:
J. Noncommut. Geom.
Verlag:
EMS
Seiten:
621–664
Band:
9, Issue 2

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