We prove that, if μ>0, then there exists a linear manifold M of harmonic functions in which is dense in the space of all harmonic functions in and lim‖x‖→∞ x ∈ S ‖x‖μDαv(x) = 0 for every v ∈ M and multi-index α, where S denotes any hyperplane strip. Moreover, every nonnull function in M is universal. In particular, if μ ≥ N+1, then every function v ∈ M satisfies ∫H vdλ =0 for every (N-1)-dimensional hyperplane H, where λ denotes the (N-1)-dimensional Lebesgue measure. On the other hand, we prove that there exists a linear manifold M of harmonic functions in the unit ball of , which is dense in the space of all harmonic functions and each function in M has zero nontangential limit at every point of the boundary of .
@article{bwmeta1.element.bwnjournal-article-cmv83i2p155bwm, author = {A. Bonilla}, title = {"Counterexamples" to the harmonic Liouville theorem and harmonic functions with zero nontangential limits}, journal = {Colloquium Mathematicae}, volume = {84/85}, year = {2000}, pages = {155-160}, zbl = {0967.31001}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-cmv83i2p155bwm} }
Bonilla, A. "Counterexamples" to the harmonic Liouville theorem and harmonic functions with zero nontangential limits. Colloquium Mathematicae, Tome 84/85 (2000) pp. 155-160. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-cmv83i2p155bwm/
[000] [1] D. H. Armitage, A non-constant continuous function on the plane whose integral on every line is zero, Amer. Math. Monthly 101 (1994), 892-894. | Zbl 0838.30035
[001] [2] D. H. Armitage and P. M. Gauthier, Recent developments in harmonic approximation, with applications, Results Math. 29 (1996), 1-15. | Zbl 0859.31001
[002] [3] D. H. Armitage and M. Goldstein, Better than uniform approximation on closed sets by harmonic functions with singularities, Proc. London Math. Soc. 60 (1990), 319-343. | Zbl 0702.31003
[003] [4] D. H. Armitage and M. Goldstein, Radial limiting behavior of harmonic functions in cones, Complex Variables 22 (1993), 267-276. | Zbl 0791.31007
[004] [5] D. H. Armitage and M. Goldstein, Nonuniqueness for the Radon transform, Proc. Amer. Math. Soc. 117 (1993), 175-178. | Zbl 0765.44001
[005] [6] D. H. Armitage and M. Goldstein, Tangential harmonic approximation on relatively closed sets, Proc. London Math. Soc. 68 (1994), 112-126. | Zbl 0795.31002
[006] [7] J. M. Ash and R. Brown, Uniqueness and nonuniqueness for harmonic functions with zero nontangential limits, Harmonic Analysis (Sendai, 1990), ICM-90 Satell. Conf. Proc., S. Igari (ed.), Springer, 1991, 30-40. | Zbl 0778.31002
[007] [8] S. Axler, P. Bourdon and W. Ramsey, Harmonic Function Theory, Springer, New York, 1992. | Zbl 0765.31001
[008] [9] L. Bernal González, A lot of 'counterexamples' to Liouville's theorem, J. Math. Anal. Appl. 201 (1996), 1002-1009. | Zbl 0855.30030
[009] [10] L. Bernal González, Small entire functions with extremely fast growth, ibid. 207 (1997), 541-548. | Zbl 0872.30022
[010] [11] L. Bernal González and A. Montes Rodríguez, Non-finite dimensional closed vector space of universal functions for composition operators, J. Approx. Theory 82 (1995), 375-391. | Zbl 0831.30024