The space B˙′ of distributions vanishing at infinity – duals of tensor products E. A. Nigsch,∗ N. Ortner† April 11, 2016 Abstract Analogous to L. Schwartz’ study of the space D′(E) of semi-regular distributions we investigate the topological properties of the space D′(B˙) of semi-regular vanishing distributions and give representations of its dual and of the scalar product with this dual. In order to determine the dual of the space of semi-regular vanishing distributions we generalize and modify a result of A. Grothendieck on the duals of E⊗F if E and F are quasi-complete and F is not necessarily semi- reflexive. b Keywords: semi-regular vanishing distributions, duals of tensor products MSC2010 Classification: 46A32, 46F05 1 Introduction arXiv:1604.02846v1 [math.FA] 11 Apr 2016 L. Schwartz investigated, in his theory of vector-valued distributions [24, 25], ′ ′ Rn Rm ′ several subspaces of the space Dxy = D ( x × y ) that are of the type Dx(Ey) where Ey is a distribution space. Three prominent examples are: ∗Wolfgang-Pauli-Institut, Oskar-Morgenstern-Platz 1, 1090 Wien, Austria. e-mail:
[email protected]. Corresponding author. †Institut f¨ur Mathematik, Universit¨at Innsbruck, Technikerstraße 13, 6020 Innsbruck, Austria. 1 ′ ′ (i) Dx(Sy) – the space of semi-temperate distributions, for which the par- tial Fourier transform is defined [24, p. 123]; ′ ′ (ii) Dx(DL1,y) – the space of partially summable distributions, for which the convolution of kernels is defined [7, §2, p. 546], as a generalization of the convolvability condition for two distributions [24, pp. 131,132]; ′ (iii) Dx(Ey) – the space of semi-regular distributions (see [23] and [24, p.