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D.5.2.25 chHom
Procedure from library chern.lib (see chern_lib).
- Usage:
- chHom(r, c, R, C [, N]); r, R polynomials (integers);
c, C lists of polynomials, N integer
- Return:
- list of polynomials
- Purpose:
- computes [up to degree N] the list of Chern classes of the vector bundle Hom(E, F)
in terms of the ranks and the Chern classes of E and F
- Note:
Example:
| LIB "chern.lib";
ring H = 0, ( r, R, c(1..3), C(1..2) ), dp;
list l=c(1..3);
list L=C(1..2);
// the Chern classes of Hom(E, F) for a vector bundle E of rank 3
// with Chern classes c(1), c(2), c(3)
// and a vector bundle F of rank 2 with Chern classes C(1) and C(2):
print( chHom(3, l, 2, L) );
// the first two Chern classes of Hom(E, F) for a vector bundle E of rank r
// with Chern classes c(1) and c(2)
// and a vector bundle G of rank R with Chern classes C(1) and C(2)
// this gives the Chern classes of a tensor product on a complex surface
l=c(1..2);
L=C(1..2);
print( chHom(r, l, R, L, 2 ) );
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