Simple description of generalized electromagnetic and gravitational hopfions
arXiv:1802.01467 · doi:10.1088/1361-6382/aaeb51
Abstract
The generalization of electromagnetic and gravitational hopfions is performed in terms of a complex scalar field. New definition of topological charge for linearized gravity is given. Quasi-local (super-)energy densities are compared for gravitational hopfion.
27 pages