decomp man page

decomp — decompose a module

Synopsis

decomp [Options] <Module> <Endo>

Description

This program decomposes a module Module into its direct summands, using the head of the endomorphism ring, Endo.  It assumes that the endomorphism ring and its left regular representation has already been calculated using mkhom(1).  It also expects that chop(1), pwkond(1), and rad(1) have been run on the left regular representation.

Decomp produces three types of output files:

Options

-Q

Quiet, no messages.

-V

Verbose, more messages.

-T <MaxTime>

Set CPU time limit

-t

Write transformed generators.

-a

Write the action on the direct summands.

Implementation Details

The algorithm used by this program was developed by Magdolna Szöke; see "Examining Green Correspondents of Weight Modules", Aachener Beiträge zur Mathematik, Band 24, Wissenschaftsverlag Mainz, Aachen, 1998.

Input Files

Module.{1,2,...}

Generators on Module.

Module.cfinfo

Constituent info file for Module.

Endo.{1,2,...}

k-Basis of the endomorphism ring.

Endo.gens.{1,2,...}

Generating system of the endomorphism ring.

Endo.lrr.{1,2,...}

Left regular representation of the endomorphism ring.

Endo.lrr.cfinfo

Constituent info file for Endo.lrr after running chop(1) and pwkond(1).

Endo.lrr.soc

Basis of the socle of Endo.lrr, made by soc(1).

Output Files

Module.dec

Basis of Module reflecting the decomposition.

Module.dec.{1,2,...}

Generators in the decomposition basis (with -t).

Module.Comp.{1,2,...}

Generators on the components (with -a).

See Also

chop(1), mkhom(1), pwkond(1), rad(1), soc(1)

Info

2.4.24 MeatAxe User Commands