Gaiotto, DavideStrominger, AndrewYin, Xi2019-09-272007Gaiotto, Davide, Andrew Strominger, and Xi Yin. 2007. “The M5-Brane Elliptic Genus: Modularity and BPS States.” Journal of High Energy Physics 2007 (8): 070–070. https://doi.org/10.1088/1126-6708/2007/08/070.1029-84791126-6708http://nrs.harvard.edu/urn-3:HUL.InstRepos:41417365The modified elliptic genus for an M5-brane wrapped on a four-cycle of a Calabi-Yau threefold encodes the degeneracies of an infinite set of BPS states in four dimensions. By holomorphy and modular invariance, it can be determined completely from the knowledge of a finite set of such BPS states. We show the feasibility of such a computation and determine the exact modified elliptic genus for an M5-brane wrapping a hyperplane section of the quintic threefold.en-USJournal Article2019-09-2710.1088/1126-6708/2007/08/070