A note on the compactness theorem for 4d Ricci shrinkers

Haslhofer, Robert; Müller, Reto

doi:10.1090/proc/12648

A note on the compactness theorem for 4d Ricci shrinkers
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by Robert Haslhofer and Reto Müller PDF

Proc. Amer. Math. Soc. 143 (2015), 4433-4437 Request permission

Abstract:

In a previous work published in 2011, we proved an orbifold Cheeger-Gromov compactness theorem for complete 4d Ricci shrinkers with a lower bound for the entropy, an upper bound for the Euler characteristic, and a lower bound for the gradient of the potential at large distances. In this note, we show that the last two assumptions in fact can be removed. The key ingredient is a recent estimate of Cheeger-Naber (2014).

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