English

The full Bochner theorem on real reductive groups

Functional Analysis 2019-12-17 v2

Abstract

The major results of Barker [3.],[3.], leading to the spherical Bochner theorem and its (spherical) extension, were made possible through the spherical transform theory of Trombi-Varadarajan [14.][14.] and were greatly controlled by the non-availability of the full (non-spherical) Harish-Chandra Fourier transform theory on a general connected semisimple Lie group, G.G. Sequel to the recently announced results of Oyadare [13.],[13.], where the full image of the Schwartz-type algebras, Cp(G),\mathcal{C}^{p}(G), under the full Fourier transform is computed to be Cp(G^):={(ξ1^)1h(ξ1^)1:hZˉ(Fϵ)}\mathcal{C}^{p}(\widehat{G}):=\{(\widehat{\xi_{1}})^{-1}\cdot h\cdot (\widehat{\xi_{1}})^{-1}:h\in\bar{\mathcal{Z}}({\mathfrak{F}}^{\epsilon})\} with Zˉ(Fϵ)\bar{\mathcal{Z}}({\mathfrak{F}}^{\epsilon}) given as the Trombi-Varadarajan image of Cp(G//K),\mathcal{C}^{p}(G//K), the present paper now gives the full Bochner theorem for GG by lifting the results of [3.][3.] to full non-spherical status. An extension of the full Bochner theorem to all of Cp(G),\mathcal{C}^{p}(G), 1p2,1\leq p\leq2, is established. It is also conjectured that every positive-definite distribution TT on GG which corresponds to a Bochner measure μ\mu on Fϵ{\mathfrak{F}}^{\epsilon} extends uniquely to an element of Cp(G)\mathcal{C}^{p}(G)' if and only if TT can be expressed as a finite sum of derivatives of a class of functions exclusively parameterized by members of Fϵ{\mathfrak{F}}^{\epsilon} and supp  (μ)Fϵ,supp\; (\mu)\subset{\mathfrak{F}}^{\epsilon}, with ϵ=(2p)1\epsilon=(\frac{2}{p})-1 for all 1p2.1\leq p\leq2. This gives the non-spherical abstract version of the extension theorem for any positive-definite distribution on G.G. Our results confirm the one-to-one correspondence between tempered invariant positive-definite distributions and the Bochner measures of the case SU(1,1)/{±1}SU(1,1)/\{\pm1\} (as computed in Barker [5.][5.]) for all G.G.

Keywords

Cite

@article{arxiv.1907.10819,
  title  = {The full Bochner theorem on real reductive groups},
  author = {Olufemi O. Oyadare},
  journal= {arXiv preprint arXiv:1907.10819},
  year   = {2019}
}

Comments

The results established here show the centrality of Trombi-Varadarajan (spherical) theory and its contribution to the Fundamental Theorem of Harmonic Analysis on Semi-simple Lie groups, recently announced by the author in arXiv. The full Bochner theorem and its abstract extension of the present paper show that classical temperedness may not be out of reach. arXiv admin note: text overlap with arXiv:1706.09047, arXiv:1706.09045, arXiv:1907.00717

R2 v1 2026-06-23T10:30:12.755Z