Avoid covariant indices in the Levi-Civita Tensor

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Alejandro Guarnizo Trilleras

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Oct 5, 2016, 4:47:15 PM10/5/16
to xAct Tensor Computer Algebra
Hi all,

I'm start learning xact and trying to make long contractions of vector fields with metrics and Levi-Civita tensors.

My manifold is defined as 


DefMetric[-1, gb[-a, -b], CD, SymbolOfCovD -> {"D", "⌡"}]


valueEta = {{-1, 0, 0, 0}, {0, 1, 0, 0}, {0, 0, 1, 0}, {0, 0, 0, 1}};


AllComponentValues[gb[{a, cartesian}, {b, cartesian}], valueEta];


After all I just simply defined a vector field as


DefTensor[A[μ], M4]


and I tried to make all possible contractions as



epsilongb[μ, ν, α, β] gb[ρ, σ] gb[γ, δ]A[-μ] A[-ν] (CD[-α][A[-β]]) (CD[-ρ][A[-σ]]) (CD[-γ][A[-δ]] //ContractMetric // PutScalar // Simplification // FullSimplify



The "problem" is that I obtained results as



There is any way to"force" xact to have all indices contravariant?. I appreciate your kind support.

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