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A SHARP CARATHÉODORY'S INEQUALITY ON THE BOUNDARY

  • 투고 : 2015.10.24
  • 발행 : 2016.07.31

초록

In this paper, a generalized boundary version of $Carath{\acute{e}}odory^{\prime}s$ inequality for holomorphic function satisfying $f(z)= f(0)+a_pz^p+{\cdots}$, and ${\Re}f(z){\leq}A$ for ${\mid}z{\mid}$<1 is investigated. Also, we obtain sharp lower bounds on the angular derivative $f^{\prime}(c)$ at the point c with ${\Re}f(c)=A$. The sharpness of these estimates is also proved.

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참고문헌

  1. T. Akyel and B. N. Ornek, A sharp Schwarz lemma at the boundary, J. Korean Soc. Math. Educ. Ser. B Pure Appl. Math. 22 (2015), no. 3, 263-273.
  2. T. Aliyev Azeroglu and B. N. Ornek, A refined Schwarz inequality on the boundary, Complex Var. Elliptic Equ. 58 (2013), no. 4, 571-577. https://doi.org/10.1080/17476933.2012.718338
  3. H. P. Boas, Julius and Julia: Mastering the art of the Schwarz lemma, Amer. Math. Monthly 117 (2010), no. 9, 770-785. https://doi.org/10.4169/000298910x521643
  4. D. M. Burns and S. G. Krantz, Rigidity of holomorphic mappings and a new Schwarz lemma at the boundary, J. Amer. Math. Soc. 7 (1994), no. 3, 661-676. https://doi.org/10.1090/S0894-0347-1994-1242454-2
  5. D. Chelst, A generalized Schwarz lemma at the boundary, Proc. Amer. Math. Soc. 129 (2001), no. 11, 3275-3278. https://doi.org/10.1090/S0002-9939-01-06144-5
  6. V. N. Dubinin, On the Schwarz inequality on the boundary for functions regular in the disk, J. Math. Sci. 122 (2004), no. 6, 3623-3629. https://doi.org/10.1023/B:JOTH.0000035237.43977.39
  7. G. M. Golusin, Geometric Theory of Functions of Complex Variable, 2nd edn., Moscow 1966.
  8. M. Jeong, The Schwarz lemma and boundary fixed points, J. Korea Soc. Math. Educ. Ser. B Pure Appl. Math. 18 (2011), no. 3, 275-284.
  9. M. Jeong, The Schwarz lemma and its applications at a boundary point, J. Korean Soc. Math. Educ. Ser. B Pure Appl. Math. 21 (2014), no. 3, 219-227.
  10. G. Kresin and V. Maz'ya, Sharp real-part theorems. A unified approach, Translated from the Russian and edited by T. Shaposhnikova. Lecture Notes in Mathematics, 1903. Springer, Berlin, 2007.
  11. M. Mateljevic, Ahlfors-Schwarz lemma and curvature, Kragujevac J. Math. 25 (2003), 155-164.
  12. M. Mateljevic, Distortion of harmonic functions and harmonic quasiconformal quasi-isometry, Rev. Roumaine Math. Pures Appl. 51 (2006), no. 5-6, 711-722.
  13. M. Mateljevic, The lower bound for the modulus of the derivatives and Jacobian of harmonic injective mappings, Filomat 29 (2015), no. 2, 221-244. https://doi.org/10.2298/FIL1502221M
  14. M. Mateljevic, Note on rigidity of holomorphic mappings & Schwarz and Jack lemma, (in preparation) ResearchGate.
  15. B. N. Ornek, Sharpened forms of the Schwarz lemma on the boundary, Bull. Korean Math. Soc. 50 (2013), no. 6, 2053-2059. https://doi.org/10.4134/BKMS.2013.50.6.2053
  16. B. N. Ornek, Caratheodory's inequality on the boundary, J. Korean Soc. Math. Educ. Ser. B Pure Appl. Math. 22 (2015), no. 2, 169-178.
  17. R. Osserman, A sharp Schwarz inequality on the boundary, Proc. Amer. Math. Soc. 128 (2000), no. 12, 3513-3517. https://doi.org/10.1090/S0002-9939-00-05463-0
  18. Ch. Pommerenke, Boundary Behaviour of Conformal Maps, Springer-Verlag, Berlin, 1992.
  19. X. Tang, T. Liu, and J. Lu, Schwarz lemma at the boundary of the unit polydisk in $\mathbb{C}^n$, Sci. China Math. 58 (2015), no. 8, 1639-1652. https://doi.org/10.1007/s11425-015-4975-7