Hankel and symmetric Toeplitz determinants for Sakaguchi starlike functions

Authors

DOI:

https://doi.org/10.24193/subbmath.2024.3.04

Keywords:

Starlike function, Sakaguchi starlike functions, Zalcman conjecture, third and forth order Hankel determinants, second, third and fourth order symmetric Toeplitz determinants

Abstract

In this paper, we consider the class of starlike functions with respect to symmetric points which are also known as Sakaguchi starlike functions. We de- termine best possible bounds on Zalcman conjecture |  and generalized Zalcman conjecture |aman − am+n−1| for n = 2 and n = 4, m = 2, respectively for such functions. Further, we compute estimate on third order and fourth order Hankel determinants. As well, we also obtain estimates on third and fourth symmetric Toeplitz determinants.

Mathematics Subject Classification (2010): 30C45, 30C80.

Received 08 April 2022; Accepted 23 June 2022.

References

Ahuja, O.P., Khatter, K., Ravichandran, V., Toeplitz determinants associated with Ma-Minda classes of starlike and convex functions, Iran. J. Sci. Technol. Trans. A Sci, 45(2021), no. 6, 2021–2027.

Ahuja, O.P., Khatter, K., Ravichandran, V., Symmetric Toeplitz determinants associated with a linear combination of some geometric expressions, Honam Math. J., 43(2021), no. 3, 465–481.

Ali, R.M., Jain, N.K., Ravichandran, V., Bohr radius for classes of analytic functions, Results Math., 74(2019), no. 4, Paper No. 179, 13 pp.

Anand, S., Jain, N.K., Kumar, S., Certain estimates of normalized analytic functions, Math. Slovaca, 72(2022), no. 1, 85–102.

Arif, M., Rani, L., Raza, M., Zaprawa, P., Fourth Hankel determinant for the family of functions with bounded turning, Bull. Korean Math. Soc, 55(2018), no. 6, 1703–1711.

Babalola, K.O., On H3(1) Hankel determinant for some classes of univalent functions, Inequal. Theory App., 6(2010), 1-7.

Brown, J.E., Tsao, A., On the Zalcman conjecture for starlike and typically real functions, Math. Z., 191(1986), no. 3, 467–474.

Carlson, F., Sur les coefficients d’une fonction bornée dans le cercle unité, Ark. Mat. Astr. Fys., 27A(1940), no. 1, 8 pp.

Cho, N.E., Kumar, V., Initial coefficients and fourth Hankel determinant for certain analytic functions, Miskolc Math. Notes, 21(2020), no. 2, 763–779.

Cho, N.E., Kumar, S., Kumar, V., Hermitian-Toeplitz and Hankel determinants for certain starlike functions, Asian-Eur. J. Math. (2021). https://doi.org/10.1142/S1793557122500425.

Goodman, A.W., Univalent Functions, Vol. II, Mariner Publishing Co., Inc., Tampa, FL, 1983.

Hayman, W.K., On the second Hankel determinant of mean univalent functions, Proc. Lond. Math. Soc., 18(1968), no. 3, 77–94.

Janteng, A., Halim, S.A., Darus, M., Coefficient inequality for a function whose derivative has a positive real part, JIPAM. J. Inequal. Pure Appl. Math., 7(2006), no. 2, Art. 50, 5 pp.

Kowalczyk, B., Lecko, A., Lecko, M., Sim, Y.J., The sharp bound of the third Hankel determinant for some classes of analytic functions, Bull. Korean Math. Soc., 55(2018), no. 6, 1859–1868.

Kowalczyk, B., Lecko, A., Sim, Y.J., The sharp bound for the Hankel determinant of the third kind for convex functions, Bull. Aust. Math. Soc., 97(2018), no. 3, 435–445.

Krishna, D.V., RamReddy, T., Second Hankel determinant for the class of Bazilevic functions, Stud. Univ. Babeș-Bolyai Math., 60(2015), no. 3, 413–420.

Krishna, D.V., Venkateswarlu, B., RamReddy, T., Third Hankel determinant for starlike and convex functions with respect to symmetric points, Ann. Univ. Mariae Curie-Skłodowska Sect. A, 70(2016), no. 1, 37–45.

Kumar, S., Çetinkaya, A., Coefficient inequalities for certain starlike and convex functions, Hacet. J. Math. Stat., 51(2022), no. 1, 156–171.

Kumar, V., Kumar, S., Bounds on Hermitian-Toeplitz and Hankel determinants for strongly starlike functions, Bol. Soc. Mat. Mex., 27(2021), no. 2, Paper No. 55, 16 pp.

Kumar, V., Kumar, S., Ravichandran, V., Third Hankel determinant for certain classes of analytic functions, in “Mathematical Analysis, I, Approximation Theory”, 223–231, Springer Proc. Math. Stat., 306, Springer, Singapore.

Kumar, S., Ravichandran, V., Functions defined by coefficient inequalities, Malays. J. Math. Sci., 11(2017), no. 3, 365–375.

Kumar, S., Ravichandran, V., Verma, S., Initial coefficients of starlike functions with real coefficients, Bull. Iranian Math. Soc., 43(2017), no. 6, 1837–1854.

Lecko, A., Sim, Y.J., Śmiarowska, B., The sharp bound of the Hankel determinant of the third kind for starlike functions of order 1/2, Complex Anal. Oper. Theory, 13(2019), no. 5, 2231–2238.

Ma, W.C., The Zalcman conjecture for close-to-convex functions, Proc. Amer. Math. Soc., 104(1988), no. 3, 741–744.

Ma, W.C., Generalized Zalcman conjecture for starlike and typically real functions, J. Math. Anal. Appl., 234(1999), no. 1, 328–339.

Obradović, M., Tuneski, N., Zalcman and generalized Zalcman conjecture for the class U, Novi Sad J. Math., 2021, https://doi.org/10.30755/NSJOM.12436.

Pommerenke, Ch., On the coefficients and Hankel determinants of univalent functions, J. Lond. Math. Soc., 41(1966), 111–122.

Pommerenke, Ch., On the Hankel determinants of univalent functions, Mathematika, 14(1967), 108–112.

Prajapat, J.K., Bansal, D., Maharana, S., Bounds on third Hankel determinant for certain classes of analytic functions, Stud. Univ. Babeș-Bolyai Math., 62(2017), no. 2, 183–195.

Prokhorov, D.V., Szynal, J., Inverse coefficients for (α, β)-convex functions, Ann. Univ. Mariae Curie-Skłodowska Sect. A, 35(1981), 125–143.

Ravichandran, V., Verma, S., Bound for the fifth coefficient of certain starlike functions, C.R. Math. Acad. Sci. Paris, 353(2015), no. 6, 505–510.

Ravichandran, V., Verma, S., Generalized Zalcman conjecture for some classes of analytic functions, J. Math. Anal. Appl., 450(2017), no. 1, 592–605.

Sakaguchi, K., On a certain univalent mapping, J. Math. Soc. Japan, 11(1959), 72–75.

Vasudevarao, A., Pandey, A., The Zalcman conjecture for certain analytic and univalent functions, J. Math. Anal. Appl., 492(2020), no. 2, 124466, 12 pp.

Venkateswarlu, B., Rani, N., Third Hankel determinant for reciprocal of bounded turning function has a positive real part of order alpha, Stud. Univ. Babeș-Bolyai Math., 62(2017), no. 3, 331–340.

Zaprawa, P., Third Hankel determinants for subclasses of univalent functions, Mediterr. J. Math., 14(2017), no. 1, Art. 19, 10 pp.

Zaprawa, P., Obradović, M., Tuneski, N., Third Hankel determinant for univalent starlike functions, Rev. R. Acad. Cienc. Exactas Fís. Nat. Ser. A Mat. RACSAM, 115(2021), no. 2, Paper No. 49, 6 pp.

Zhang, H.Y., Srivastava, R., Tang, H., Third-order Hankel and Toeplitz determinants for starlike functions connected with the sine function, Mathematics, 7(2019), Paper No. 404, 10 pp.

Zhang, H.Y., Tang, H., Fourth Toeplitz determinants for starlike functions defined by using the sine function, J. Funct. Spaces, (2021), Art. ID 4103772, 7 pp.

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Published

2024-09-23

How to Cite

KUMAR, S. ., ANAND, S. ., & JAIN, N. K. . (2024). Hankel and symmetric Toeplitz determinants for Sakaguchi starlike functions. Studia Universitatis Babeș-Bolyai Mathematica, 69(3), 517–534. https://doi.org/10.24193/subbmath.2024.3.04

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