🧄Metric Determinant and Cross Product in Scaled Coordinates

The problem demonstrated how coordinate scaling affects the geometry of space, starting with the transformation y3=2x3y^3=2 x^3. This scaling leads to a diagonal metric tensor where only the g33g_{33} component is altered, becoming 1 / 4, resulting in a metric determinant of g=1/4g=1 / 4. The key implication is how this value scales the vector calculus operations: the Levi-Civita density ηabc\eta^{a b c}, crucial for the cross product, is scaled by 1/g=21 / \sqrt{g}=2. Consequently, the contravariant components of the cross product, (v×w)a=ηabcvbwc(v \times w)^a=\eta^{a b c} v_b w_c, are simply twice the magnitude of the standard Cartesian cross product involving the covariant components of the vectors, illustrating the general principle that all tensor operations in non-Cartesian coordinates must incorporate factors derived from the metric determinant.

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