This library is a toolbox for symbolic computations with Chern classes.
The Aluffi's algorithms for computation of characteristic classes of algebraic varieties
(Segre, Fulton, Chern-Schwartz-MacPherson classes) are implemented as well
The current version of the library chern.lib is available on
An informal discussion of the algorithms implemented in the library:
On different approaches to compute the Chern classes of a tensor product of two vector bundles
A comparison of different algorithms implemented in the library to compute the Chern classes of a tensor
product of two vector bundles:
needed to obtain all the formulas for the Chern classes of tensor products E⊗F with rank(E⊗F)=N.
The Singular code
used for testing the four different implementations.
total Chern class and the Hilbert polynomial
of the Horrocks-Mumford bundle
Things that can be computed with the help of the library in around 1 second.
(Laptop 2 x Intel Celeron 2957U @ 1.4 GHz with 8.3 GB of RAM)
first 38 terms
of the Chern character.
first 16 terms
of the Todd class.
first 12 Chern classes
of a tensor product of two
Chern classes of all exterior powers
of a rank 11
vector bundle of a 3-fold.
Chern classes of 9 first symmetric powers
of a rank 5
vector bundle of a 4-fold.