nLab exotic brane

Idea

Exotic branes are non-perturbative branes in non-perturbative string theory, describing non-geometric backgrounds.

According to deBoer & Shigemori 2012, p. 12 these may be identified as codimension-2 defect branes with U-duality-group monodromy.

Figure 1 from (BMO19). «A comparison of the objects covered by the geometric solutions (backed by orange hashing) and non-geometric solutions (backed by green hashing) out of all the branes down to codimension-$2$ and¹ $0\leq\alpha\leq -2$, as well as their M-theory lifts. Red lines denote T-duality, blue lines denote lifts/reductions and black lines denote S-dualities.»

Related concepts

• non-geometry, T-fold

• double field theory

• defect brane

References

• Jan de Boer, Masaki Shigemori, Exotic Branes in String Theory, Physics Reports 532 (2013) 65-118 (arXiv:1209.6056, doi:j.physrep.2013.07.003)

  (discussion as defect branes with U-duality-group monodromy)

• David Berman, Felix J. Rudolph, Branes are Waves and Monopoles (arXiv:1409.6314)

• David Berman, Edvard Musaev, Ray Otsuki, Exotic Branes in M-Theory, contribution to: Dualities and Generalized Geometries, Corfu Summer Institute 2018 (arXiv:1903.10247)

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1. Here $\alpha$ denotes the exponent with which the brane’s tension $T$ scales with the string coupling constant $g_s$ as $T \propto (g_s)^\alpha$, according to BMO 2019, p. 2. ↩