Macaulay2 » Documentation
Packages » DirectSummands » Example: summands of the Frobenius pushforward » frobeniusPullback

next | previous | forward | backward | up | index | toc

frobeniusPullback -- compute Frobenius pullbacks

Usage:

frobeniusPullback(e, M)
Inputs:
- e, an integer,
- M, a ring, an ideal, a module, a matrix, a coherent sheaf, or a morphism of sheaves,
Outputs:
- a ring,
- a module,
- a matrix,
- a coherent sheaf,
- a morphism of sheaves,

Description

This function computes pullback along the $e$-fold Frobenius morphism.

See also

frobeniusMap -- the iterated Frobenius map of a ring in positive characteristic
frobeniusPushforward -- compute Frobenius pushforwards

Ways to use frobeniusPullback:

frobeniusPullback(ZZ,Ideal)
frobeniusPullback(ZZ,Matrix)
frobeniusPullback(ZZ,Module)
frobeniusPullback(ZZ,Ring)

For the programmer

The object frobeniusPullback is a method function.

The source of this document is in DirectSummands/docs.m2:680:0.