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ConformalBlocks :: killsCurves

killsCurves -- given an S_n symmetric divisor D, produces a list of symmetric F-curves C such that C dot D = 0

Synopsis

Description

Given a symmetric divisor D on M0,n, this function returns the list of symmetric F curves C such that D . C=0.

Here is an example from the paper [AGSS]: When n is even, the divisor Dn1,n/2 is zero on even F-curves and 1 on odd F-curves. (Here the parity of Fa,b,c,d is defined to be the parity of the product abcd.) In the calculations below, we check this claim for n=8.

i1 : D=symmetricDivisorM0nbar(8,3*B_2+2*B_3+4*B_4)

o1 = 3*B  + 2*B  + 4*B
        2      3      4

o1 : S_8-symmetric divisor on M-0-8-bar
i2 : killsCurves(D)

o2 = {{4, 2, 1, 1}, {3, 2, 2, 1}, {2, 2, 2, 2}}

o2 : List

Ways to use killsCurves :