Chiral Brst Cohomology of N=2 Strings at Arbitrary Ghost and Picture Number *
نویسنده
چکیده
We compute the BRST cohomology of the holomorphic part of the N=2 string at arbitrary ghost and picture number. We confirm the expectation that the relative cohomology at non-zero momentum consists of a single massless state in each picture. The absolute cohomology is obtained by an independent method based on homological algebra. For vanishing momentum, the relative and absolute cohomologies both display a picture dependence — a phenomenon discovered recently also in the relative Ramond sector of N=1 strings by Berkovits and Zwiebach [1]. ∗ supported in part by the ‘Deutsche Forschungsgemeinschaft’; grant LE-838/5-1
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