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Fundamental strings and NS5-branes from unstable D-branes in supergravity

J. X. Lu·S. Roy
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Abstract

By using the non-supersymmetric $p$-brane solutions delocalized in arbitrary number of transverse directions in type II supergravities, we show how they can be regarded as interpolating solutions between unstable D$p$-branes (a non-BPS D-brane or a pair of coincident D-brane-antiD-brane) and fundamental strings and also between unstable D$p$-branes and NS5-branes. We also show that some of these solutions can be regarded as interpolating solutions between NS5/$\bar{\rm NS}$5 and D$p$-branes (for $p \leq 5$). This gives a closed string description of the tachyon condensation and lends support to the conjecture that the open string theory on unstable D-branes at the tachyonic vacuum has soliton solutions describing not only the lower dimensional BPS D-branes, but also the fundamental strings as well as the NS5-branes.

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J. X. Lu, S. Roy. 2006-04-12. Fundamental strings and NS5-branes from unstable D-branes in supergravity. https://doi.org/10.1016/j.physletb.2006.04.006

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