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The relative Riemann-Roch theorem from Hochschild homology

Ajay C. Ramadoss
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Abstract

This write up attempts to clarify a preprint by Markarian [2] which proves This paper attempts to clarify a preprint of Markarian [2]. The preprint by Markarian [2] proves the relative Riemann-Roch theorem using a result describing how the HKR map fails to respect comultiplication. This paper elaborates on the core computations in [2]. These computations show that the HKR map twisted by the square root of the Todd genus "almost preserves" the Mukai pairing. This settles a part of a conjecture of Caldararu[3]. The relative Riemann-Roch theorem follows from this and a result of Caldararu[4].

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Ajay C. Ramadoss. 2007-04-06. The relative Riemann-Roch theorem from Hochschild homology. https://arxiv.org/abs/math/0603127

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