Sphere recognition lies in NP [unknown]

Saul Schleimer
2011 Low-dimensional and Symplectic Topology   unpublished
We prove that the three-sphere recognition problem lies in the complexity class NP. Our work relies on Thompson's original proof that the problem is decidable [Math. Res. Let., 1994], Casson's version of her algorithm, and recent results of Agol, Hass, and Thurston [STOC, 2002].
doi:10.1090/pspum/082/2768660 fatcat:7t7jhkfawjhl5hpprzgtdwbsjm