lrcalc - Calculate with Littlewood-Richardson coefficients
lrcalc coprod [-a] part
lrcalc lrcoef outer - inner1 -
inner2
lrcalc lrtab [-r rows] outer /
inner
lrcalc mult [-mz] [-r rows] [-q
rows,cols] [-f rows,level] part1
- part2
lrcalc skew [-m] [-r rows] outer
/ inner
DESCRIPTION
The command "lrcalc coprod
z" lists all pairs of partitions x and y for which the
Littlewood-Richardson coefficient c^z_{x,y} is non-zero, with that coefficient
in front.
OPTIONS
EXAMPLE
% lrcalc coprod 3 2 1
1 (3, 1) (2)
1 (2, 2) (1, 1)
1 (3, 1) (1, 1)
1 (2, 1) (3)
2 (2, 1) (2, 1)
1 (2, 2, 1) (1)
1 (3, 2, 1) ()
1 (3, 2) (1)
1 (2, 1, 1) (2)
1 (3, 1, 1) (1)
1 (1, 1, 1) (2, 1)
1 (2, 1, 1) (1, 1)
1 (2, 2) (2)
DESCRIPTION
The command "lrcalc lrcoef z
- x - y" computes the Littlewood-Richardson
coefficient c^z_{x,y} which is the coefficient of the Schur function s_z in
the product s_x * s_y.
EXAMPLE
% lrcalc lrcoef 3 2 1 - 2 1 - 2 1
2
DESCRIPTION
The command "lrcalc mult x
- y" lists all partitions z for which the
Littlewood-Richardson coefficient c^z_{x,y} is non-zero, with that coefficient
in front.
OPTIONS
- -mz
- not documented
- -r rows
- not documented
- -q
rows,cols
- Calculates quantum coefficients. Experimental feature.
- -f
rows,level
- Calculates fusion coefficients. Experimental feature.
EXAMPLES
% lrcalc mult 2 1 - 2 1
1 (3, 3)
1 (4, 2)
1 (2, 2, 1, 1)
1 (2, 2, 2)
2 (3, 2, 1)
1 (4, 1, 1)
1 (3, 1, 1, 1)
% lrcalc mult -f 3,2 3 2 1 - 3 2 1
1 (4, 4, 4)
1 (5, 4, 3)
% lrcalc mult -q 3,2 3 2 1 - 3 2 1
1 (2)
1 (1, 1)
DESCRIPTION
The command "lrcalc skew z
/ x" lists all partitions y for which the
Littlewood-Richardson coefficient c^z_{x,y} is non-zero, with that coefficient
in front.
OPTIONS
EXAMPLE
% lrcalc skew 3 2 1 / 2 1
1 (3)
2 (2, 1)
1 (1, 1, 1)
Anders S. Buch <asbuch at math rutgers edu>
Tobias Hansen <thansen at debian dot org>