Special and general types
Syntomic cohomology is the abelian sheaf cohomology of the syntomic site of a scheme.
It is closely related to the crystalline cohomology of that scheme. It may be regarded as an example of an absolute cohomology theory.
The syntomic site was introduced in
- Jean-Marc Fontaine and William Messing, -Adic periods and -adic etale cohomology (pdf)
Further developments are in
- Amnon Besser, Syntomic regulators and -adic integration I: rigid syntomic regulators (pdf)