Abstract
We establish both sufficient and necessary conditions for weighted Hardy inequalities in metric spaces in terms of Assouad (co)dimensions. Our sufficient conditions in the case where the complement is thin are new, even in euclidean spaces, while in the case of a thick complement, we give new formulations for previously known sufficient conditions which reveal a natural duality between these two cases. Our necessary conditions are rather straight-forward generalizations from the unweighted case but, together with some examples, indicate the essential sharpness of our results. In addition, we consider the mixed case in which the complement may contain both thick and thin parts.
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References
H. Aikawa, Quasiadditivity of Riesz capacity, Math. Scand. 69 (1991), 15–30.
H. Aikawa, Quasiadditivity of capacity and minimal thinness, Ann. Acad. Sci. Fenn. Ser. A I Math. 18 (1993), 65–75.
H. Aikawa and M. Essén, Potential Theory—Selected Topics, Springer-Verlag, Berlin, 1996.
A. Björn and J. Björn, Nonlinear Potential Theory on Metric Spaces, European Mathematical Society (EMS), Zürich, 2011.
A. Björn, J. Björn, and J. Lehrbäck, Sharp capacity estimates for annuli in weighted Rn and in metric spaces, Math. Z., to appear. doi:10.1007/s00209-0016-1797-4.
A. Björn, J. Björn, and N. Shanmugalingam, Sobolev extensions of Hölder continuous and characteristic functions on metric spaces, Canad. J. Math. 59 (2007), 1135–1153.
J. Björn, P. MacManus, and N. Shanmugalingam, Fat sets and pointwise boundary estimates for p-harmonic functions in metric spaces, J. Anal. Math. 85 (2001), 339–369.
B. Dyda and A. V. Vähäkangas, A framework for fractional Hardy inequalities, Ann. Acad. Sci. Fenn. Math. 39 (2014), 675–689.
K. Falconer, Fractal Geometry. Mathematical Foundations and Applications, JohnWiley & Sons, Ltd., Chichester, 1990.
J. Fraser, Assouad type dimensions and homogeneity of fractals, Trans. Amer. Math. Soc. 366 (2014), 6687–6733.
F. W. Gehring, The Lp-integrability of the partial derivatives of a quasiconformal mapping, Acta Math. 130 (1973), 265–277.
P. Hajłasz, Pointwise Hardy inequalities, Proc. Amer. Math. Soc. 127 (1999), 417–423.
P. Hajłasz and P. Koskela, Sobolev met Poincaré, Mem. Amer.Math. Soc. 145 (2000), no. 688.
G. H. Hardy, J. E. Littlewood, and G. Pólya, Inequalities, 2nd ed, Cambridge University Press, Cambridge, 1952.
J. Heinonen, Lectures on Analysis on Metric Spaces, Springer-Verlag, New York, 2001.
J. Heinonen, P. Koskela, N. Shanmugalingam, and J. T. Tyson, Sobolev Spaces on Metric Measure Spaces: an Approach Based on Upper Gradients, Cambridge University Press, Cambridge, 2015.
L. Ihnatsyeva and A. V. Vähäkangas, Hardy inequalities in Triebel–Lizorkin spaces II. Aikawa dimension, Ann. Mat. Pura Appl. (4) 94 (2015), 479–493.
A. Käenmäki, J. Lehrbäck, and M. Vuorinen, Dimensions, Whitney covers, and tubular neighborhoods, Indiana Univ. Math. J. 62 (2013), 1861–1889.
S. Keith and X. Zhong, The Poincaré inequality is an open ended condition, Ann. of Math. (2) 167 (2008), 575–599.
R. Korte, J. Lehrbäck, and H. Tuominen, The equivalence between pointwise Hardy inequalities and uniform fatness, Math. Ann. 351 (2011), 711–731.
R. Korte and N. Shanmugalingam, Equivalence and self-improvement of p-fatness and Hardy’s inequality, and association with uniform perfectness, Math. Z. 264 (2010), 99–110.
P. Koskela and J. Lehrbäck, Weighted pointwise Hardy inequalities, J. London Math. Soc. (2) 79 (2009), 757–779.
P. Koskela and X. Zhong, Hardy’s inequality and the boundary size, Proc. Amer. Math. Soc. 131 (2003), 1151–1158.
D. G. Larman, A new theory of dimension, Proc. London Math. Soc. (3) 17 (1967), 178–192.
J. Lehrbäck, Weighted Hardy inequalities and the size of the boundary, Manuscripta Math. 127 (2008), 249–273.
J. Lehrbäck, Self-improving properties of weighted Hardy inequalities, Adv. Calc. Var. 1 (2008), 193–203.
J. Lehrbäck, Necessary conditions for weighted pointwise Hardy inequalities, Ann. Acad. Sci. Fenn. Math. 34 (2009), 437–446.
J. Lehrbäck, Weighted Hardy inequalities beyond Lipschitz domains, Proc. Amer.Math. Soc. 142 (2014), 1705–1715.
J. Lehrbäck and N. Shanmugalingam, Quasiadditivity of variational capacity, Potential Anal. 40 (2014), 247–265.
J. Lehrbäck and H. Tuominen, A note on the dimensions of Assouad and Aikawa, J. Math. Soc. Japan 65 (2013), 343–356.
J. Lewis, Uniformly fat sets, Trans. Amer. Math. Soc. 308 (1988), 177–196.
J. Luukkainen, Assouad dimension: antifractal metrization, porous sets, and homogeneous measures, J. Korean Math. Soc. 35 (1998), 23–76.
P. Mattila, Geometry of Sets and Measures in Euclidean Spaces, Cambridge Univ. Press, Cambridge, 1995.
S. Secchi, D. Smets, and M. Willem, Remarks on a Hardy-Sobolev inequality, C. R. Math. Acad. Sci. Paris 336 (2003), 811–815.
J. O. Strömberg and A. Torchinsky, Weighted Hardy Spaces, Springer-Verlag, Berlin, 1989.
A. Wannebo, Hardy inequalities, Proc. Amer. Math. Soc. 109 (1990), 85–95.
Q. H. Yang, Hardy type inequalities related to Carnot–Carathéodory distance on the Heisenberg group, Proc. Amer Math. Soc. 141 (2013), 351–362.
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The author has been supported by the Academy of Finland, grant no. 252108.
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Lehrbäck, J. Hardy inequalities and Assouad dimensions. JAMA 131, 367–398 (2017). https://doi.org/10.1007/s11854-017-0013-8
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DOI: https://doi.org/10.1007/s11854-017-0013-8