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Sets of zero discrete harmonic density

Published online by Cambridge University Press:  20 November 2009

COLIN C. GRAHAM
Affiliation:
Department of Mathematics, University of British Columbia, V6T 1Y4 Vancouver, B.C., Canada. e-mail: ccgraham@alum.mit.edu
KATHRYN E. HARE
Affiliation:
Department of Pure Mathematics, University of Waterloo, Waterloo, Ontario N2L 3G1 Canada. e-mail: kehare@uwaterloo.ca

Abstract

Let G be a compact, connected, abelian group with dual group Γ. The set E has zero discrete harmonic density (z.d.h.d.) if for every open UG and μ ∈ Md(G) there exists ν ∈ Md(U) with = on E. I0 sets in the duals of these groups have z.d.h.d. We give properties of such sets, exhibit non-Sidon sets having z.d.h.d., and prove union theorems. In particular, we prove that unions of I0 sets have z.d.h.d. and provide a new approach to two long-standing problems involving Sidon sets.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 2009

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References

REFERENCES

[1]Bourgain, J. Subspaces of l N, arithmetical diameter and Sidon sets. in Probability in Banach spaces, V (Medford, Mass., 1984), 96127. Lecture Notes in Math. 1153 (Springer, Berlin, 1985).Google Scholar
[2]Déchamps–Gondim, M.Ensembles de Sidon topologiques. Ann. Inst. Fourier (Grenoble) 22, fasc.3 (1972).CrossRefGoogle Scholar
[3]Déchamps, M. and Selles, O.Compacts associés aux sommes de suites lacunaires. Publ. Math. Orsay 01 (1996) 2740Google Scholar
[4]Gaposhkin, V. F.A uniqueness theorem for multiple lacunary trigonometric series. Mat. Zametki 16 (1974) 865870 (Translated in Math. Notes 16 (1974) 1112–1115)Google Scholar
[5]Graham, C. C. and Hare, K. E.ϵ-Kronecker and I 0 sets in abelian groups, I: arithmetic properties of ϵ-Kronecker sets. Math. Proc. Camb. Phil. Soc. 140 (2006), no. 3, 475489.CrossRefGoogle Scholar
[6]Graham, C. C. and Hare, K. E.ϵ-Kronecker and I 0 sets in abelian groups, III: Interpolation by measures on small sets, Studia Math. 171 (2005), no. 1, 1532.CrossRefGoogle Scholar
[7]Graham, C. C., Hare, K. E. and Ramsey, L. T.Union problems for I 0 sets. Acta Sci. Math. (Szeged) 75 (2009), 175195.Google Scholar
[8]Graham, C. C. and McGehee, O. CarruthEssays in Commutative Harmonic Analysis. (Springer-Verlag 1979).CrossRefGoogle Scholar
[9]Hadamard, J.Essai sur l'étude des fonctions données par leur développement de Taylor. J. Math. Pures Appl. (4) 8 (1892) 101186Google Scholar
[10]Kahane, J.-P. and Katznelson, Y.Entiers aléatoires et analyse harmonique. J. Anal. Math. 105 (2008), 363378.CrossRefGoogle Scholar
[11]Kalton, J. N.On Vector-valued inequalities for Sidon sets and sets of interpolation. Colloq. Math. 54 (1993) 233244CrossRefGoogle Scholar
[12]Lopez, J. and Ross, K.Sidon sets. Lecture Notes in Pure and Applied Math. 13 (Marcel Dekker 1975).Google Scholar
[13]Méla, J.-F.Approximation diophantine et ensembles lacunaires. Mem. Bull. Math. Soc. France 19 (1969) 2654Google Scholar
[14]Ramsey, L. T.A theorem of C. Ryll-Nardzewski and metrizable l.c.a. groups. Proc. Amer. Math. Soc. 78 (1980) no. 2, 221224CrossRefGoogle Scholar
[15]Rudin, W.Fourier Analysis on Groups. (Wiley Interscience 1962).Google Scholar
[16]Ryll-Nardzewski, C.Concerning almost periodic extensions of functions. Colloq. Math. 12 (1964) 235237CrossRefGoogle Scholar
[17]Shapiro, G. S.Balayage in Fourier transforms: general results, perturbation, and balayage with sparse frequencies. Trans. Amer. Math. Soc. 225 (1977), 183198.CrossRefGoogle Scholar
[18]Shapiro, G. S.Unique balayage in Fourier transforms on compact abelian groups. Proc. Amer. Math. Soc. 70 (1978), no. 2, 146150.CrossRefGoogle Scholar
[19]Zygmund, A.On a theorem of Hadamard. Ann. Soc. Polon. Math. 21 (1948) 5269Google Scholar