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A Note on a Proposal for the Tachyon State in Vacuum String Field Theory

Leonardo Rastelli·Ashoke Sen·Barton Zwiebach
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Abstract

We discuss the proposal of Hata and Kawano for the tachyon fluctuation around a solution of vacuum string field theory representing a D25 brane. We give a conformal field theory construction of their state -- a local insertion of a tachyon vertex operator on the sliver surface state, and explain why the on-shell momentum condition emerges correctly. We also show that a naive computation of the D25-brane tension using data for the three point coupling of this state gives an answer that is $(π^2/3)(16/27\ln 2)^3 \simeq 2.0558$ times the expected answer. We demonstrate that this problem arises because the HK state does not satisfy the equations of motion in a strong sense required for the computation of D-brane tension from the on-shell 3-tachyon coupling.

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Leonardo Rastelli, Ashoke Sen, Barton Zwiebach. 2001-11-16. A Note on a Proposal for the Tachyon State in Vacuum String Field Theory. https://doi.org/10.1088/1126-6708%2F2002%2F02%2F034

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