Advances in Theoretical and Mathematical Physics

Half-BPS M2-brane orbifolds

Paul de Medeiros and José Figueroa-O'Farrill

Full-text: Access denied (no subscription detected)

We're sorry, but we are unable to provide you with the full text of this article because we are not able to identify you as a subscriber. If you have a personal subscription to this journal, then please login. If you are already logged in, then you may need to update your profile to register your subscription. Read more about accessing full-text


Smooth Freund–Rubin backgrounds of eleven-dimensional supergravity of the form AdS$_4 \times X^7$ and preserving at least half of the supersymmetry have been recently classified. Requiring that amount of supersymmetry forces $X$ to be a spherical space form, whence isometric to the quotient of the round 7-sphere by a freely acting finite subgroup of SO(8). The classification is given in terms of ADE subgroups of the quaternions embedded in SO(8) as the graph of an automorphism. In this paper, we extend this classification by dropping the requirement that the background be smooth, so that $X$ is now allowed to be an orbifold of the round 7-sphere. We find that if the background preserves more than half of the supersymmetry, then it is automatically smooth in accordance with the homogeneity conjecture, but that there are many half-BPS orbifolds, most of them new. The classification is now given in terms of pairs of ADE subgroups of quaternions fibred over the same finite group. We classify such subgroups and then describe the resulting orbifolds in terms of iterated quotients. In most cases, the resulting orbifold can be described as a sequence of cyclic quotients.

Article information

Adv. Theor. Math. Phys. Volume 16, Number 5 (2012), 1349-1408.

First available in Project Euclid: 20 August 2014

Permanent link to this document

Mathematical Reviews number (MathSciNet)

Zentralblatt MATH identifier


de Medeiros, Paul; Figueroa-O'Farrill, José. Half-BPS M2-brane orbifolds. Adv. Theor. Math. Phys. 16 (2012), no. 5, 1349--1408.

Export citation