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Hi, please give me some leeway for my laziness here:
We have that , in the finite-dimensional case for vector spaces, V~V** in a natural, i.e.,
basis-independent way ; one way of proving this is by showing that the identity functor is
naturally-isomorphic to the double-dual functor. An easy way of showing that this is not the
case for V~V* is that the two functors ( identity and 1st-dual ) go in opposite directions.
Questions:
1) Is there a canonical bilinear form B:V-->V** here that gives us the isomorphism V~V**? How do we show there is no such form from V to V*?
2) How/why does the functor argument showing V~V** fail when V is infinite-dimensional?
Thanks for answers, hints, refs.
We have that , in the finite-dimensional case for vector spaces, V~V** in a natural, i.e.,
basis-independent way ; one way of proving this is by showing that the identity functor is
naturally-isomorphic to the double-dual functor. An easy way of showing that this is not the
case for V~V* is that the two functors ( identity and 1st-dual ) go in opposite directions.
Questions:
1) Is there a canonical bilinear form B:V-->V** here that gives us the isomorphism V~V**? How do we show there is no such form from V to V*?
2) How/why does the functor argument showing V~V** fail when V is infinite-dimensional?
Thanks for answers, hints, refs.