Let $ \mathbb{U} $ be the open unit disk, $ \Omega = \{\omega\in \mathbb{C}:{\rm Re}\; \omega > a, -\infty < a < a_{0} < +\infty\} $ with $ a, a_{0}\in\mathbb{R} $, and $ K\geq1 $ and $ K'\geq0 $ as two given constants. In this paper, we study some properties of the class $ \mathcal{H}(\mathbb{U}, \Omega) $ of mappings consisting of those sense-preserving Euclidean harmonic mappings from $ \mathbb{U} $ onto $ \Omega $ with the real, normalized conditions of $ f(0) = a_{0}, f_{z}(0) > 0 $ and $ f_{\overline{z}}(0) $. We first show that a $ (K, K') $-quasiconformal mapping $ f\in\mathcal{H}(\mathbb{U}, \Omega) $ need not be Euclidean Lipschitz continuous. Subsequently, we give a sufficient and necessary condition for $ f\in\mathcal{H}(\mathbb{U}, \Omega) $ to be $ (K, K') $-quasiconformal. Additionally, coefficient estimates, distortion theorems, and area theorems are obtained.
Citation: Deguang Zhong, Meilan Huang. Some properties for $ (K, K') $-quasiconformal harmonic mappings to half-planes[J]. Electronic Research Archive, 2026, 34(4): 2539-2547. doi: 10.3934/era.2026117
Let $ \mathbb{U} $ be the open unit disk, $ \Omega = \{\omega\in \mathbb{C}:{\rm Re}\; \omega > a, -\infty < a < a_{0} < +\infty\} $ with $ a, a_{0}\in\mathbb{R} $, and $ K\geq1 $ and $ K'\geq0 $ as two given constants. In this paper, we study some properties of the class $ \mathcal{H}(\mathbb{U}, \Omega) $ of mappings consisting of those sense-preserving Euclidean harmonic mappings from $ \mathbb{U} $ onto $ \Omega $ with the real, normalized conditions of $ f(0) = a_{0}, f_{z}(0) > 0 $ and $ f_{\overline{z}}(0) $. We first show that a $ (K, K') $-quasiconformal mapping $ f\in\mathcal{H}(\mathbb{U}, \Omega) $ need not be Euclidean Lipschitz continuous. Subsequently, we give a sufficient and necessary condition for $ f\in\mathcal{H}(\mathbb{U}, \Omega) $ to be $ (K, K') $-quasiconformal. Additionally, coefficient estimates, distortion theorems, and area theorems are obtained.
| [1] |
D. Kalaj, M. Mateljević, $(K, K')$-quasiconformal harmonic mappings, Potential Anal., 36 (2012), 117–135. https://doi.org/10.1007/s11118-011-9222-4 doi: 10.1007/s11118-011-9222-4
|
| [2] | P. Duren, Harmonic Mappings in the Plane, Cambridge University Press, 2009. https://doi.org/10.1017/CBO9780511546600 |
| [3] |
H. Lewy, On the non-vanishing of the Jacobian in certain one-to-one mappings, Bull. Am. Math. Soc., 42 (1936), 689–692. https://doi.org/10.1090/S0002-9904-1936-06397-4 doi: 10.1090/S0002-9904-1936-06397-4
|
| [4] | A. Livingston, Univalent harmonic mappings, Ann. Polonici Math., 57 (1992), 57–70. |
| [5] | A. Livingston, Univalent harmonic mapping II, Ann. Polonici Math., 67 (1997), 131–145. |
| [6] | M. Öztürk, Univalent harmonic mappings onto half planes, Turk. J. Math., 23 (1999), 301–313. |
| [7] | W. Hengartner, G. Schober, Univalent harmonic functions, Trans. Am. Math. Soc., 299 (1987), 1–31. https://doi.org/10.2307/2000478 |
| [8] |
Y. Abu-Muhanna, G. Schober, Harmonic mappings onto convex domains, Can. J. Math., 39 (1987), 1489–1530. https://doi.org/10.4153/CJM-1987-071-4 doi: 10.4153/CJM-1987-071-4
|
| [9] |
O. Martio, On harmonic quasiconformal mappings, Ann. Fenn. Math., 425 (1969), 421–450. https://doi.org/10.5186/aasfm.1969.425 doi: 10.5186/aasfm.1969.425
|
| [10] | D. Kalaj, M. Pavlovic, Boundary correspondence under harmonic quasiconformal diffeomorphisms of a half-plane, Ann. Fenn. Math., 30 (2005), 159–165. |
| [11] |
D. Fu, X. Huang, Harmonic $K$-quasiconformal mappings from unit disk onto half planes, Bull. Malays. Math. Sci. Soc., 39 (2016), 339–347. https://doi.org/ 10.1007/s40840-015-0174-5 doi: 10.1007/s40840-015-0174-5
|
| [12] | M. Pavlovic, Boundary correspondence under harmonic quasiconformal homeomorphisms of the unit disk, Ann. Fenn. Math., 27 (2002), 365–372. |
| [13] |
Z. G. Wang, L. Shi, Y. P. Jiang, On harmonic $K$-quasiconformal mappings associated with asymmetric vertical strips, Acta. Math. Sin. Engl. Ser., 31 (2015), 1970–1976. https://doi.org/ 10.1007/s10114-015-4773-8 doi: 10.1007/s10114-015-4773-8
|
| [14] |
M. Chen, X. Chen, $(K, K')$-quasiconformal harmonic mappings of the upper half plane onto itself, Ann. Fenn. Math., 37 (2012), 265–276. https://doi.org/10.5186/aasfm.2012.3716 doi: 10.5186/aasfm.2012.3716
|
| [15] |
P. Li, J. Chen, X. Wang, Quasiconformal solutions of Poisson equations, Bull. Aust. Math. Soc., 92 (2015), 420–428. https://doi.org/10.1017/S0004972715000891 doi: 10.1017/S0004972715000891
|