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D-branes as Tachyon Lumps in String Field Theory

Nicolas Moeller·Ashoke Sen·Barton Zwiebach
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Abstract

It has been conjectured that the tachyonic lump solution of the open bosonic string field theory describing a D-brane represents a D-brane of one lower dimension. We place the lump on a circle of finite radius and develop a variant of the level expansion scheme that allows systematic account of all higher derivative terms in the string field theory action, and gives a calculational scheme that can be carried to arbitrary accuracy. Using this approach we obtain lump masses that agree with expected D-brane masses to an accuracy of about 1%. We find convincing evidence that in string field theory the lump representing a D-brane is an extended object with a definite profile. A gaussian fit to the lump gives a 6-sigma size of 9.3 \sqrt{α'}. The level truncation scheme developed here naturally gives rise to an infrared and ultraviolet cut-off, and may be useful in the study of quantum string field theory.

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Nicolas Moeller, Ashoke Sen, Barton Zwiebach. 2000-05-03. D-branes as Tachyon Lumps in String Field Theory. https://doi.org/10.1088/1126-6708%2F2000%2F08%2F039

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