One-loop unitarity of string theories in a constant external background and their Seiberg-Witten limit
Bassetto, A, Torrielli, A and Valandro, R (2004) One-loop unitarity of string theories in a constant external background and their Seiberg-Witten limit Journal of High Energy Physics (01).
Perturbative spectra and related factorization properties of one-loop open string amplitudes in the presence of a constant external background B are analysed in detail. While the pattern of the closed string spectrum, obtained after a careful study of the properly symmetrized amplitudes, turns out to be unaffected by the presence of B, a series of double open-string poles, which would be absent when B is turned off, can couple owing to a partial symmetry loss. These features are studied first in a bosonic setting and then generalized in the more satisfactory superstring context. When the background is of an ``electric'' type, a classical perturbative instability is produced beyond a critical value of the electric field. In the Seiberg-Witten limit this instability is the origin of the unphysical tachyonic cut occurring in the non-planar amplitudes of the corresponding noncommutative field theories.
|Divisions :||Faculty of Engineering and Physical Sciences > Mathematics|
|Date :||1 January 2004|
|Identification Number :||https://doi.org/10.1088/1126-6708/2004/01/040|
|Related URLs :|
|Additional Information :||Copyright 2004 Institute of Physics. This is the author's accepted manuscript.|
|Depositing User :||Symplectic Elements|
|Date Deposited :||21 Feb 2012 14:50|
|Last Modified :||23 Sep 2013 18:57|
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