Oriented Borel-Moore homology is a generalization of the theory of Chow groups on schemes over a field . The additivity of the first Chern class operator (the formula ), is replaced by imposing a formal group law , i.e. . Algebraic cobordism is the universal oriented Borel-Moore homology theory. This is a direct analogue of the complex cobordism of Quillen.
(Co)homological theories for algebraic varieties have led Grothendieck to propose a theory of motives which has partly been realized (e.g. in its triangulated and dg-versions) so far. One systematic approach is to study the homotopy theory in this context, namely -homotopy theory. However in practice, one is led to calculate invariants and it is difficult to find new computable cases; the study of algebraic cycles in higher codimension is notoriously difficult, and the Chow groups are difficult to compute. Somewhat more accessible is algebraic K-theory. This is unlike the classical situation where in addition many other extraordinary (co)homology theories are at hand. In the abstract setup, Voevodsky and others did study more general extraordinary cohomology theories, but down-to-Earth examples are difficult to find. This was roughly the motivation for two people – Marc Levine and Fabien Morel – to construct in a single effort the notion of algebraic cobordism, which is an analogue of complex cobordism for algebraic varieties. Many of the tools from Quillen’s and Novikov’s work on complex cobordism, like Lazard’s ring and formal groups, play a major role.
Algebraic cobordism is the universal oriented Borel–Moore homology theory, where ‘oriented’ stands for the existence of the proper? direct image homomorphisms. The fact that -homotopy theory is not used —that is, the constructions are more direct— is an advantage.
On the other hand a universal oriented motivic cohomology theory is not the algebraic cobordism of Morel and Levine but rather the cohomology associated to the motivic spectrum of Voevodsky, which is different and also may be called a theory of algebraic cobordism. An early different approach to some sort of algebraic cobordism is from late 1970-s work of Victor Snaith, discussed in that entry.
The original announcements:
A very complete book:
An Oberwolfach workshop:
An equivalent and simpler construction was given in
The construction was extended to derived schemes in the paper
The close connection of algebraic cobordism with K-theory is discussed in
An algebraic analogue of h-cobordism:
Algebraic cobordism in mixed characteristic: