The method is named “Nyström approximation” because it can be interpreted as a case of the Nyström method from integral equations theory.
Reference List
- https://en.wikipedia.org/wiki/Low-rank_matrix_approximations
- Petros Drineas and Michael W. Mahoney (2005). “On the Nyström Method for Approximating a Gram Matrix for Improved Kernel-Based Learning”. Journal of Machine Learning Research 6, pp. 2153–2175.