We prove an oscillation theorem of two meromorphic functions whose derivatives share four values IM. From this we obtain some uniqueness theorems, which improve the corresponding results given by Yang [16] and Qiu [10...We prove an oscillation theorem of two meromorphic functions whose derivatives share four values IM. From this we obtain some uniqueness theorems, which improve the corresponding results given by Yang [16] and Qiu [10], and supplement results given by Nevanlinna [9] and Gundersen [3, 4]. Some examples are provided to show that the results in this paper are best possible.展开更多
Let K be a complete algebraically closed p-adic field of characteristic zero. We apply results in algebraic geometry and a new Nevanlinna theorem for p-adic meromorphic functions in order to prove results of uniquenes...Let K be a complete algebraically closed p-adic field of characteristic zero. We apply results in algebraic geometry and a new Nevanlinna theorem for p-adic meromorphic functions in order to prove results of uniqueness in value sharing prob-lems, both on K and on C. Let P be a polynomial of uniqueness for meromorphic functions in K or C or in an open disk. Let f , g be two transcendental meromorphic functions in the whole field K or in C or meromorphic functions in an open disk of K that are not quotients of bounded analytic functions. We show that if f′P′（ f ） and g′P′（g） share a small function α counting multiplicity, then f=g, provided that the multiplicity order of zeros of P′satisfy certain inequalities. A breakthrough in this pa-per consists of replacing inequalities n≥k＋2 or n≥k＋3 used in previous papers by Hypothesis （G）. In the p-adic context, another consists of giving a lower bound for a sum of q counting functions of zeros with （q-1） times the characteristic function of the considered meromorphic function.展开更多
We establish several upper-bound estimates for the growth of meromorphic functions with radially distributed value. We also obtain a normality criterion for a class of meromorphic functions, where any two of whose dif...We establish several upper-bound estimates for the growth of meromorphic functions with radially distributed value. We also obtain a normality criterion for a class of meromorphic functions, where any two of whose differential polynomials share a non-zero value. Our theorems improve some previous results.展开更多
We consider transcendental merornorphic solutions with N（r, f） = S（r, f） of the following type of nonlinear differential equations：f^n ＋ Pn-2（f） = p1（z）e~α1（z） ＋ p2（z）^α2（z）,where n ≥2 is an intege...We consider transcendental merornorphic solutions with N（r, f） = S（r, f） of the following type of nonlinear differential equations：f^n ＋ Pn-2（f） = p1（z）e~α1（z） ＋ p2（z）^α2（z）,where n ≥2 is an integer, Pn-2（f） is a differential polynomial in f of degree not greater than n-2 with small functions of f as its coefficients, p1（z）, p2（z） are nonzero small functions of f1 and α1（z）, α2（z） are nonconstant entire functions. In particular, we give out the conditions for ensuring the existence of meromorphic solutions and their possible forms of the above equation. Our results extend and improve some known results obtained most recently.展开更多
基金supported by the NSFC (11171184), the NSFC(10771121),the NSFC (40776006) the NSFC & RFBR (Joint Project) (10911120056),the NSF of Shandong Province, China (Z2008A01), and the NSF of Shandong Province, China (ZR2009AM008)
文摘We prove an oscillation theorem of two meromorphic functions whose derivatives share four values IM. From this we obtain some uniqueness theorems, which improve the corresponding results given by Yang [16] and Qiu [10], and supplement results given by Nevanlinna [9] and Gundersen [3, 4]. Some examples are provided to show that the results in this paper are best possible.
基金Partially funded by the research project CONICYT (Inserción de nuevos investigadores en la academia, NO. 79090014) from the Chilean Government
文摘Let K be a complete algebraically closed p-adic field of characteristic zero. We apply results in algebraic geometry and a new Nevanlinna theorem for p-adic meromorphic functions in order to prove results of uniqueness in value sharing prob-lems, both on K and on C. Let P be a polynomial of uniqueness for meromorphic functions in K or C or in an open disk. Let f , g be two transcendental meromorphic functions in the whole field K or in C or meromorphic functions in an open disk of K that are not quotients of bounded analytic functions. We show that if f′P′（ f ） and g′P′（g） share a small function α counting multiplicity, then f=g, provided that the multiplicity order of zeros of P′satisfy certain inequalities. A breakthrough in this pa-per consists of replacing inequalities n≥k＋2 or n≥k＋3 used in previous papers by Hypothesis （G）. In the p-adic context, another consists of giving a lower bound for a sum of q counting functions of zeros with （q-1） times the characteristic function of the considered meromorphic function.
基金Acknowledgements This work was supported by the Visiting Scholar Program of Chern Institute of Mathematics at Nankai University when the first and third authors worked as visiting scholars. The authors wish to thank the anonymous referees for their very helpful comments and useful suggestions. This work was also supported by the National Natural Science Foundation of China （Grant No. 11271090）, the Tianyuan Youth Fund of the National Natural Science Foundation of China （Grant No. 11326083）, the Shanghai University Young Teacher Training Program （ZZSDJ12020）, the Innovation Program of Shanghai Municipal Education Commission （14YZ164）, the Natural Science Foundation of Guangdong Province （S2012010010121）, and the Projects （13XKJC01） from the Leading Academic Discipline Project of Shanghai Dianji University.
文摘We establish several upper-bound estimates for the growth of meromorphic functions with radially distributed value. We also obtain a normality criterion for a class of meromorphic functions, where any two of whose differential polynomials share a non-zero value. Our theorems improve some previous results.
基金Sponsored by NNSF of China(Grant No.11671191)Natural Science Foundation of Shanghai(Grant No.17ZR1402900)
文摘We consider transcendental merornorphic solutions with N（r, f） = S（r, f） of the following type of nonlinear differential equations：f^n ＋ Pn-2（f） = p1（z）e~α1（z） ＋ p2（z）^α2（z）,where n ≥2 is an integer, Pn-2（f） is a differential polynomial in f of degree not greater than n-2 with small functions of f as its coefficients, p1（z）, p2（z） are nonzero small functions of f1 and α1（z）, α2（z） are nonconstant entire functions. In particular, we give out the conditions for ensuring the existence of meromorphic solutions and their possible forms of the above equation. Our results extend and improve some known results obtained most recently.
