cohomologous forms
1Closed and exact differential forms — In mathematics, especially vector calculus and differential topology, a closed form is a differential form α whose exterior derivative is zero (dα = 0), and an exact form is a differential form that is the exterior derivative of another …
2De Rham cohomology — For Grothendieck s algebraic de Rham cohomology see Crystalline cohomology. In mathematics, de Rham cohomology (after Georges de Rham) is a tool belonging both to algebraic topology and to differential topology, capable of expressing basic… …
3Projective representation — In the mathematical field of representation theory, a projective representation of a group G on a vector space V over a field F is a group homomorphism from G to :PGL( V ,F) = GL( V ,F)/F lowast; where GL( V ,F) is the automorphism group of… …
