2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/53100Topological quantum field theories can be used to probe topological properties of low dimensional manifolds. A class of these theories known as Schwarz type theories, comprise of Chern-Simons theories and BF theories. In three dimensions both capture the properties of knots and links leading to invariants characterising them. These can also be used to construct three-manifold invariants. Three dimensional gravity is described by these field theories. BF theories exist also in higher dimensions. In four dimensions, these describe two-dimensional generalization of knots as well as Donaldson invariants.20 pages, Prepared for Encyclopedia of Mathematical Physics, paragraph added minor corrections and few references addedHigh Energy Physics - Theorytext