This paper is devoted to studying the growth of solutions of $ f''+A(z)f'+B(z)f = 0 $, where $ A(z) $ and $ B(z) $ are meromorphic functions. With some additional conditions, we show that every non-trivial solution $ f $ of the above equation has infinite order. In addition, we also obtain the lower bound of measure of the angular domain, in which the radial order of $ f $ is infinite.
Citation: Zheng Wang, Zhi Gang Huang. Infinite growth of solutions of second order complex differential equations with meromorphic coefficients[J]. AIMS Mathematics, 2022, 7(4): 6807-6819. doi: 10.3934/math.2022379
This paper is devoted to studying the growth of solutions of $ f''+A(z)f'+B(z)f = 0 $, where $ A(z) $ and $ B(z) $ are meromorphic functions. With some additional conditions, we show that every non-trivial solution $ f $ of the above equation has infinite order. In addition, we also obtain the lower bound of measure of the angular domain, in which the radial order of $ f $ is infinite.
[1] | P. D. Barry, Some theorems related to the $\cos\pi\rho$ theorem, Proc. Lond. Math. Soc., 21 (1970), 334–360. https://doi.org/10.1112/plms/s3-21.2.334 doi: 10.1112/plms/s3-21.2.334 |
[2] | A. Baernstein, Proof of Edreis spread conjecture, Proc. Lond. Math. Soc., 26 (1973), 418–434. https://doi.org/10.1112/plms/s3-26.3.418 doi: 10.1112/plms/s3-26.3.418 |
[3] | Z. X. Chen, The growth of solutions of the differential equation $f''+e^{-z}f'+Q(z)f = 0$, Sci. China Ser. A, 45 (2002), 290–300. https://doi.org/10.1360/02ye9035 doi: 10.1360/02ye9035 |
[4] | S. A. Gao, Z. X. Chen, T. W. Chen, Complex Oscillation Theory of Linear Differential Equations, Wuhan: Huazhong University of Science and Technology Press, 1998 (Chinese). |
[5] | G. G. Gundersen, Finite order solutions of second order linear differential equations, Trans. Amer. Math. Soc., 305 (1988), 415–429. https://doi.org/10.1090/S0002-9947-1988-0920167-5 doi: 10.1090/S0002-9947-1988-0920167-5 |
[6] | G. G. Gundersen, Estimates for the logarithmic derivative of a meromorphic function, plus similar estimates, J. Lond. Math. Soc., 37 (1998), 88–104. |
[7] | G. G. Gundersen, On the real zeros of solutions of $f''+A(z)f = 0$, where $A(z)$ is entire, Ann. Acad. Sci. Fenn. Math., 11 (1986), 275–294. https://doi.org/10.5186/aasfm.1986/1105 doi: 10.5186/aasfm.1986/1105 |
[8] | G. G. Gundersen, On the question of whether $f''+e^{-z}f'+Q(z) = 0$ can admit a solution $f\not\equiv 0$ of finite order, Pro. Roy. Soc. Edinburgh Sect. A, 102 (1986), 9–17. https://doi.org/10.1017/S0308210500014451 doi: 10.1017/S0308210500014451 |
[9] | W. K. Hayman, Meromorphic Functions, Clarendon Press, Oxford, 1964. |
[10] | S. Hellerstein, J. Miles, J. Rossi, On the growth of solutions of $f''+gf'+hf = 0$, Trans. Amer. Math. Soc., 324 (1991), 693–705. https://doi.org/10.1056/NEJM199103073241027 doi: 10.1056/NEJM199103073241027 |
[11] | Z. G. Huang, J. Wang, The radial oscillation of entire solutions of complex differential equations, J. Math. Anal. Appl., 431 (2015), no. 2,988–999. |
[12] | Z.B.Huang, Z.X.Chen, Angular distribution with hyper-order in complex oscillation theory, Acta Math Sinica, 50 (2007), 601–614. https://doi.org/10.1080/00140130601154954 doi: 10.1080/00140130601154954 |
[13] | I. Laine, P. C. Wu, Growth of solutions of second order linear differential equations, Proc. Amer. Math. Soc., 128 (2000), 2693–2703. https://doi.org/10.1090/S0002-9939-00-05350-8 doi: 10.1090/S0002-9939-00-05350-8 |
[14] | I. Laine, Nevanlinna Theory and Complex Differential Equations, Walter de Gruyter, Berlin, 1993. https://doi.org/10.1515/9783110863147 |
[15] | S. T. Lan, Z. X. Chen, On the growth of meromorphic solutions of difference equations, Ukrainian Mathematical Journal, 68 (2017), 1561–1570. |
[16] | J. R. Long, Growth of solutions of second order linear differential equations with extremal functions for Denjoy's conjecture as coeffcients, Tamkang J. Math., 47 (2016), 237–247. https://doi.org/10.5556/j.tkjm.47.2016.1914 doi: 10.5556/j.tkjm.47.2016.1914 |
[17] | J. R. Long, Growth of solutions of second order complex linear differential equations with entire coefficients, Filomat, 32 (2018), 275–284. https://doi.org/10.2298/FIL1801275L doi: 10.2298/FIL1801275L |
[18] | A. I. Markushevich, Theory of Functions of a Complex Variable, Vol.II, Revised English Edition Translated and Edited by Richard A. Silverman. Prentice-Hall, Inc., Englewood Cliffs, N. J., 1965. |
[19] | M. Ozawa, On a solution of $w''+e^{-z}w'+(az+b)w = 0$, Kodai Math. J., 3 (1980), 295–309. |
[20] | L. Qiu, S. J. Wu, Radial distributions of Julia sets of meromorphic functions, J. Aust. Math. Soc., 81 (2006), 363–368. https://doi.org/10.1017/S1446788700014361 doi: 10.1017/S1446788700014361 |
[21] | L. Qiu, Z. X. Xuan, Y. Zhao, Radial distribution of Julia sets of some entire functions with infinite lower order, Chinese Ann. Math. Ser. A, 40 (2019), 325–334. |
[22] | X. B. Wu, J. R. Long, J. Heittokangas, K. E. Qiu, Second-order complex linear differential equations with special functions or extremal functions as coefficients, Electronic J. Differential Equa., 143 (2015), 1–15. https://doi.org/10.5089/9781513546261.002 doi: 10.5089/9781513546261.002 |
[23] | P. C. Wu, J. Zhu, On the growth of solutions of the complex differential equation $f''+Af'+Bf = 0$, Sci. China Ser. A, 54 (2011), 939–947. https://doi.org/10.1007/s11425-010-4153-x doi: 10.1007/s11425-010-4153-x |
[24] | S. J. Wu, Angular distribution in complex oscillation theory, Sci. China Math, 48 (2005), 107–114. https://doi.org/10.1360/03YS0159 doi: 10.1360/03YS0159 |
[25] | S. J. Wu, On the growth of solution of second order linear differential equations in an angle, Complex. Var. Elliptic, 24 (1994), 241–248. https://doi.org/10.1080/17476939408814716 doi: 10.1080/17476939408814716 |
[26] | N. Wu, Growth of solutions to linear complex differential equations in an angular region, Electron. J. Diff. Equ, 183 (2013), 1–8. |
[27] | J. F. Xu, H. X. Yi, Solutions of higher order linear differential equation in an angle, Appl. Math. Lett, 22 (2009), 484–489. |
[28] | L. Yang, Value Distribution Theory, Springer, Berlin, 1993. |
[29] | G. W. Zhang, L. Z. Yang, Infinite growth of solutions of second order complex differential equations with entire coefficient having dynamical property, Appl. Math. Lett., 112 (2021), 1–8. |