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COEFFICIENT BOUNDS FOR CLOSE-TO-CONVEX FUNCTIONS ASSOCIATED WITH VERTICAL STRIP DOMAIN

  • Bulut, Serap (Faculty of Aviation and Space Sciences Kocaeli University)
  • Received : 2019.08.01
  • Accepted : 2020.03.10
  • Published : 2020.07.31

Abstract

By considering a certain univalent function in the open unit disk 𝕌, that maps 𝕌 onto a strip domain, we introduce a new class of analytic and close-to-convex functions by means of a certain non-homogeneous Cauchy-Euler-type differential equation. We determine the coefficient bounds for functions in this new class. Relevant connections of some of the results obtained with those in earlier works are also provided.

Keywords

References

  1. S. Bulut, Coefficient bounds for certain subclasses of close-to-convex functions of complex order, Filomat 31 (2017), no. 20, 6401-6408. https://doi.org/10.2298/fil1720401b
  2. S. Bulut, M. Hussain, and A. Ghafoor, On coefficient bounds of some new subfamilies of close-to-convex functions of complex order related to generalized differential operator, Asian-Eur. J. Math. 13 (2020), no. 3, 8 pp. https://doi.org/10.1142/S1793557120500497
  3. W. Kaplan, Close-to-convex schlicht functions, Michigan Math. J. 1 (1952), 169-185 (1953). http://projecteuclid.org/euclid.mmj/1028988895 https://doi.org/10.1307/mmj/1028988895
  4. K. Kuroki and S. Owa, Notes on new class for certain analytic functions, RIMS Kokyuroku 1772 (2011), 21-25.
  5. R. J. Libera, Some radius of convexity problems, Duke Math. J. 31 (1964), 143-158. http://projecteuclid.org/euclid.dmj/1077375085 https://doi.org/10.1215/S0012-7094-64-03114-X
  6. M. O. Reade, On close-to-convex univalent functions, Michigan Math. J. 3 (1955), 59-62. http://projecteuclid.org/euclid.mmj/1031710535 https://doi.org/10.1307/mmj/1031710535
  7. M. I. S. Robertson, On the theory of univalent functions, Ann. of Math. (2) 37 (1936), no. 2, 374-408. https://doi.org/10.2307/1968451
  8. W. Rogosinski, On the coefficients of subordinate functions, Proc. London Math. Soc. (2) 48 (1943), 48-82. https://doi.org/10.1112/plms/s2-48.1.48
  9. H. M. Srivastava, O. Altintas, and S. K. Serenbay, Coefficient bounds for certain subclasses of starlike functions of complex order, Appl. Math. Lett. 24 (2011), no. 8, 1359-1363. https://doi.org/10.1016/j.aml.2011.03.010
  10. H. M. Srivastava, Q.-H. Xu, and G.-P. Wu, Coefficient estimates for certain subclasses of spiral-like functions of complex order, Appl. Math. Lett. 23 (2010), no. 7, 763-768. https://doi.org/10.1016/j.aml.2010.03.005
  11. W. Ul-Haq, A. Nazneen, M. Arif, and N. Rehman, Coefficient bounds for certain subclasses of close-to-convex functions of Janowski type, J. Comput. Anal. Appl. 16 (2014), no. 1, 133-138.
  12. W. Ul-Haq, A. Nazneen, and N. Rehman, Coefficient estimates for certain subfamilies of close-to-convex functions of complex order, Filomat 28 (2014), no. 6, 1139-1142. https://doi.org/10.2298/FIL1406139U
  13. B. A. Uralegaddi, M. D. Ganigi, and S. M. Sarangi, Univalent functions with positive coefficients, Tamkang J. Math. 25 (1994), no. 3, 225-230. https://doi.org/10.5556/j.tkjm.25.1994.4448