Multilinear Maps of V^n into Reals and Effect of Linear Transforma

[WWGD]

Hi, All:

Is there a "nice" , non-messy way of showing this:

Let [itex]M(v_1,v_2,..,v_n) → R⁺[/itex], where R is the Reals, be a multilinear map,

where $v_i$ are vectors in a finite-dimensional vector space V.

Now, let [itex] L: Vⁿ → Vⁿ [/itex] be a linear map with Det(L)>0 .

How do we show that $M(L(v_1,v_2,..,v_n))($ is also strictly-positive? I think it

has to see with the fact that the map L preserves the orientation of [itex]Vⁿ[/itex],

but I don't see how to make this more rigorous. Any ideas?

 

[fresh_42]

I would write $M,L$ as tensors and search whether there are some nice formulas which connect tensors and determinantes, or otherwise go the hard way by coordinates.