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On Vanishing Two Loop Cosmological Constants in Nonsupersymmetric Strings

Shamit Kachru·Eva Silverstein
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Abstract

It has recently been suggested that in certain special nonsupersymmetric type II string compactifications, at least the first two perturbative contributions to the cosmological constant $Λ$ vanish. Support for perturbative vanishing beyond 1-loop (as well as evidence for the absence of some nonperturbative contributions) has come from duality arguments. There was also a direct 2-loop computation which was incomplete; in this note we explain the deficiency of the previous 2-loop calculation and discuss the complete 2-loop computation in two different models. The corrected analysis yields a vanishing 2-loop contribution to $Λ$ in these models.

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Shamit Kachru, Eva Silverstein. 1998-10-16. On Vanishing Two Loop Cosmological Constants in Nonsupersymmetric Strings. https://doi.org/10.1088/1126-6708%2F1999%2F01%2F004

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