Volume Form
Let ω be a form on a n-dimensional real vector space V, ω ∈ Λ2(V). Then ω is non-degenerate if and only if n is even, and ωn/2 = ω ∧ ... ∧ ω is a volume form. A volume form on a n-dimensional vector space V is a non-zero multiple of the n-form e1∗ ∧ ... ∧ en∗ where e1, e2, ..., en is a basis of V.
For the standard basis defined in the previous section, we have
By reordering, one can write
Authors variously define ωn or (−1)n/2ωn as the standard volume form. An occasional factor of n! may also appear, depending on whether the definition of the alternating product contains a factor of n! or not. The volume form defines an orientation on the symplectic vector space (V, ω).
Read more about this topic: Symplectic Vector Space
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