Abstract
We consider the convolution of right half-plane harmonic mappings in the unit disk \(\mathbb {D}:=\{z\in \mathbb {C}:\, |z|<1\}\) with respective dilatations \( e^{i \alpha }(z + a)/(1 + a z)\) and \(-z\), where \(-1< a < 1\) and \(\alpha \in \mathbb {R}\). We prove that such convolutions are locally univalent and convex in the horizontal direction under certain condition.
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References
Aleman, A., Constantin, A.: Harmonic maps and ideal fluid flows. Arch. Ration. Mech. Anal. 204, 479–513 (2012)
Cohn, A.: Über die Anzahl der Wurzeln einer algebraischen Gleichung in einem Kreise. Math. Z. 14, 110–148 (1922)
Clunie, J., Sheil-Small, T.: Harmonic univalent functions. Ann. Acad. Sci. Fenn. Ser. A.I. 9, 3–25 (1984)
Constantin, O., Martin, M.J.: A harmonic maps approach to fluid flows. Math. Ann. 369, 1–16 (2017)
Dorff, M.: Convolutions of planar harmonic convex mappings. Complex Variables Theory Appl. 45, 263–271 (2001)
Dorff, M., Nowak, M., Woloszkiewicz, M.: Convolutions of harmonic convex mappings. Complex Var. Elliptic Equ. 57, 489–503 (2012)
Goodloe, R.M.: Hadamard products of convex harmonic mappings. Complex Var. Theory Appl. 47, 81–92 (2002)
Li, L., Ponnusamy, S.: Solution to an open problem on convolutions of harmonic mappings. Complex Var. Elliptic Equ. 58(12), 1647–1653 (2013)
Li, L., Ponnusamy, S.: Convolutions of slanted half-plane harmonic mappings. Analysis (Munich) 33(2), 159–176 (2013)
Liu, Z., Ponnusamy, S.: Univalency of convolutions of univalent harmonic right half-plane mappings. Comput. Methods Funct. Theory 17(2), 1647–1653 (2017)
Lewy, H.: On the non-vanishing of the Jacobian in certain one-to-one mappings. Bull. Am. Math. Soc. 42, 689–692 (1936)
Ruscheweyh, St, Sheil-Small, T.: Corrigendum: Hadamard products of schlicht functions and the Pólya–Schoenberg conjecture. Comment. Math. Helv. 48, 119–135 (1973)
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The second author thanks SERB-MATRICS for the support.
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Communicated by Adrian Constantin.
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Ali, M.F., Allu, V. & Ghosh, N. A convolution property of univalent harmonic right half-plane mappings. Monatsh Math 193, 729–736 (2020). https://doi.org/10.1007/s00605-020-01442-3
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DOI: https://doi.org/10.1007/s00605-020-01442-3
Keywords
- Analytic
- Univalent
- Starlike
- Convex
- Close-to-convex functions
- Close-to-convex harmonic mappings
- Convolution
- Right half-plane mappings