Characteristic class

In mathematics, the idea of characteristic class is one of the unifying geometric concepts in algebraic topology, differential geometry and algebraic geometry. The theory explains, in very general terms, why fiber bundles cannot always have sections. In other words, characteristic classes are global invariants which measure the deviation of a local product structure from a product structure.

See also

• Stiefel-Whitney class
• Chern class
• Pontryagin class
• Euler class