On Albanese torsors and the elementary obstruction

We show that the elementary obstruction to the existence of 0-cycles of degree 1 on an arbitrary variety X (over an arbitrary field) can be expressed in terms of the Albanese 1-motives associated with dense open subsets of X. Arithmetic applications are given

Weighted PLB-spaces of continuous functions arising as tensor products of a Fréchet and a DF-space

Countable projective limits of countable inductive limits, so-called PLB-spaces, of weighted Banach spaces of continuous functions have recently been investigated by Agethen, Bierstedt and Bonet, who analyzed locally convex properties in terms of the defining double sequence of weights. We complement their results by considering a defining sequence which is the product of two single sequences. By associating these two sequences with a weighted Fr\'{e}chet, resp. LB-space of continuous functions or with two weighted Fr\'{e}chet spaces (by taking the reciprocal of one of the sequences) we derive a representation of the PLB-space as the tensor product of a Fr\'{e}chet and a DF-space and exhibit a connection between the invariants (DN) and ($\Omega$) for Fr\'{e}chet spaces and locally convex properties of the PLB-space resp. of the forementioned tensor product.Comment: Version of October 10, 2010. 9 page