We introduce two new subclasses UΣ(α, λ) and ℬ1Σ(α) of analytic bi-univalent functions defined in an open unit disk 𝕌, which are associated with the Bazilevich functions. In addition, for functions from these subclasses, we obtain sharp bounds for the initial Taylor–Maclaurin coefficients a2 and a3, as well as the sharp estimate for the Fekete–Szegő functional \({a}_{3}-{\mu a}_{2}^{2}.\)
Similar content being viewed by others
References
R. M. Ali, S. K. Lee, and M. Obradović, “Sharp bounds for initial coefficients and the second Hankel determinant,” Bull. Korean Math. Soc., 57, No. 4, 839–850 (2020).
R. M. Ali, V. Ravichandran, and N. Seenivasagan, “Coefficient bounds for p-valent functions,” Appl. Math. Comput., 187, No. 1, 35–46 (2007).
Ş. Altinkaya and S. Yalçin, “Fekete–Szegő inequalities for certain classes of bi-univalent functions,” Int. Sch. Res. Notices, Article ID 327962, 1–6 (2014).
D. A. Brannan and J. G. Clunie (Eds), “Aspects of contemporary complex analysis,” Proc. of the NATO Advanced Study Institute Held at the University of Durham, Durham, July 1–20 (1979), Academic Press, London, New York (1980).
D. A. Brannan and T. S. Taha, “On some classes of bi-univalent functions,” Stud. Univ. Babeş-Bolyai Math., 31, No. 2, 70–77 (1986).
P. L. Duren, “Univalent functions,” Grundlehren Math. Wiss., 259 (1983).
R. Fournier and S. Ponnusamy, “A class of locally univalent functions defined by a differential inequality,” Complex Var. Elliptic Equat., 52, No. 1, 1–8 (2007).
B. A. Frasin and M. K. Aouf, “New subclasses of bi-univalent functions,” Appl. Math. Lett., 24, 1569–1573 (2011).
S. B. Joshi, S. S. Joshi, and H. Pawar, “On some subclasses of bi-univalent functions associated with pseudo-starlike functions,” J. Egypt. Math. Soc., 24, No. 4, 522–525 (2016).
M. Lewin, “On a coefficient problem for bi-univalent functions,” Proc. Amer. Math. Soc., 18, 63–68 (1967).
U. H. Naik and A. B. Patil, “On initial coefficient inequalities for certain new subclasses of bi-univalent functions,” J. Egypt. Math. Soc., 25, No. 3, 291–293 (2017).
Z. Nehari, Conformal Mapping, McGraw-Hill Book Co., New-York–Toronto–London (1952).
M. Obradović, “A class of univalent functions,” Hokkaido Math. J., 27, No. 2, 329–335 (1998).
M. Obradović, “A class of univalent functions II,” Hokkaido Math. J., 28, No. 3, 557–562 (1999).
M. Obradović, S. Ponnusamy, and K.-J. Wirths, “Coefficient characterizations and sections for some univalent functions,” Sib. Math. J., 54, 679–696 (2013).
M. Obradović, S. Ponnusamy, and K.-J.Wirths, “Geometric studies on the class U(λ),” Bull. Malays. Math. Sci. Soc., 39, 1259–1284 (2016).
A. B. Patil and U. H. Naik, “Bounds on initial coefficients for a new subclass of bi-univalent functions,” New Trends Math. Sci., 6, No. 1, 85–90 (2018).
A. B. Patil and T. G. Shaba, “On sharp Chebyshev polynomial bounds for a general subclass of bi-univalent functions,” Appl. Sci., 23, 109–117 (2021).
C. Pommerenke, Univalent Functions, Vandenhoeck & Rupercht, G¨ottingen (1975).
S. Porwal and M. Darus, “On a new subclass of bi-univalent functions,” J. Egypt. Math. Soc., 21, No. 3, 190–193 (2013).
R. Singh, “On Bazilević functions,” Proc. Amer. Math. Soc., 38, 261–271 (1973).
H. M. Srivastava and D. Bansal, “Coefficient estimates for a subclass of analytic and bi-univalent functions,” J. Egypt. Math. Soc., 23, No. 2, 242–246 (2015).
H. M. Srivastava, A. K. Mishra, and P. Gochhayat, “Certain subclasses of analytic and bi-univalent functions,” Appl. Math. Lett., 23, 1188–1192 (2010).
D. Styer and D. J. Wright, “Results on bi-univalent functions,” Proc. Amer. Math. Soc., 82, No. 2, 243–248 (1981).
D. L. Tan, “Coefficient estimates for bi-univalent functions,” Chin. Ann. Math. Ser. A, 5, 559–568 (1984).
A.Vasudevarao and H. Yanagihara, “On the growth of analytic functions in the class U(λ),” Comput. Meth. Funct. Theory, 13, 613–634 (2013).
P. Zaprawa, “On the Fekete–Szegő problem for classes of bi-univalent functions,” Bull. Belg. Math. Soc. Simon Stevin, 21, No. 1, 169–178 (2014).
Author information
Authors and Affiliations
Corresponding author
Additional information
Published in Ukrains’kyi Matematychnyi Zhurnal, Vol. 74, No. 2, pp. 198–206, February, 2023. Ukrainian https://doi.org/10.37863/umzh.v75i2.6602.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Patil, A.B., Shaba, T.G. Sharp Initial Coefficient Bounds and the Fekete–Szegő Problem for Some Subclasses of Analytic and Bi-Univalent Functions. Ukr Math J 75, 225–234 (2023). https://doi.org/10.1007/s11253-023-02195-6
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11253-023-02195-6