target space, background gauge field twisted smooth cohomology in string theory landscape of string theory vacua An M5-brane wrapped on a torsion 3-cycle is called a fractional M2-brane in Aharony, Bergman & Jafferis 2008, §2.2. Neil Lambert, David Tong, Membranes on an Orbifold, Phys. Rev. Lett. 101 041602 (2008) [arXiv:0804.1114] Ofer Aharony, Oren Bergman, Daniel Jafferis, Fractional M2-branes, JHEP 0811:043 (2008) [arXiv:0807.4924, doi:10.1088/1126-6708/2008/11/043] Stefano Cremonesi, Type IIB construction of flavoured ABJ(M) and fractional M2 branes, J. High Energ. Phys. 2011 76 (2011) [doi:10.1007/JHEP01(2011)076, arXiv:1007.4562] See also: