The log-canonical threshold of
A defined by a polynomial
f is the least number
c for which the multiplier ideal
J(f^c) is nontrivial.
Let's consider Example 6.3 of Berkesch and Leykin from arXiv:1002.1475v2:
i1 : R := QQ[x,y,z];
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i2 : f := toList factor((x^2 - y^2)*(x^2 - z^2)*(y^2 - z^2)*z) / first;
|
i3 : A := arrangement f
o3 = {z, y - z, y + z, x - z, x + z, x - y, x + y}
o3 : Hyperplane Arrangement
|
i4 : lct A
3
o4 = -
7
o4 : QQ
|
note that
A is allowed to be a multiarrangement.