Chair Professor, Department of Mathematics, Indian Institute of Technology Madras, Chennai-600 036, India.

E-mail:

Websites: Personal webpage

Education

→ Doctor of Philosophy (Mathematics), IIT Kanpur (1983-1989).

→ Master of Science (Mathematics), University of Madras, India, 1982.

→ Bachelor of Education (Mathematics), University of Madras, India, 1980.

Main Research field

Complex Analysis, Quasiconformal and Harmonic Mappings, Special Functions and Function Spaces.

Rewards (main)

→ "Best Selling Author Award, 2002" for the book entitled "Foundations of Complex Analysis, 1995, 464 pp.".

→ "C.L. Chandana Mathematics Award" by the Canadian World Education Foundation 2002 in recognition of distinguished and outstanding contribution to Mathematics Research and Teaching in India.

→ "Tamilnadu Scientist Award (TANSA)-2003" in recognition of outstanding research, teaching and popularization of mathematical sciences in the state of Tamilnadu, India.

→ Elected the "Fellow of The National Academy of Sciences, India, in the year 2005.

→ Appointed as "Senior Associate" of The Abdus Salam International Centre for Theoretical Physics (1 Jan.2008 until 31 Dec. 2013).

→ Awarded a "TWAS-UNESCO Associateship" appointment (for the period of three years, 2009-2011) by TWAS-UNESCO Associateship scheme at Centers of Excellence in the South.

→ Founding "Fellow of the Forum de Analystes", Chennai, India, 1992.

→ Elected as Vice-President of the "Fellow of the Forum de Analystes", Chennai, India (2007 onward).

→ Elected as Vice-President of the "Indian Academy of Mathematics", Indore (2006 onward).

→ Awarded the "Guest Professor, Hengyang Normal University, China," (2013–2016).

→ Elected as President of the "Ramanujan Mathematical Society", India (April 2019 – March 2022; April 2022 to March 2025).

Publications (recent):

2024

→ L. Li, S. Ponnusamy, K.-J. Wirths, "An elementary counterexample to a coefficient conjecture", Comput. Methods Funct. Theory, 24 (2024), 229–239, DOI.

→ G. Liu, S. Ponnusamy, "The link on extraneous non-repelling cycles of Schroder's methods of the first and second kind", Journal of Mathematical Analysis and Applications, 534 (2024), 128071, 16 p., DOI.

→ M.-S. Liu, S. Ponnusamy, "Landau-type theorems for certain bounded bi-analytic functions and biharmonic mappings", Canadian Mathematical Bulletin, 67 (1) (2024), 152–165, DOI.

→ S. Ponnusamy, E. S. Shmidt, V. V. Starkov, "The Bohr radius and its modifications for linearly invariant families of analytic functions", Journal of Mathematical Analysis and Applications, 533 (2024), 128039, 9 p., DOI.

→ X.-Y. Wang, S. Ponnusamy, J.-H Fan, "Ahlfors type p-valent conditions for biharmonic functions", Journal of Mathematical Analysis and Applications, 537 (2024), 128273, 20 p., DOI.

→ Q. Zhou, S. Ponnusamy, "Quasihyperbolic geodesics are cone arcs", The Journal of Geometric Analysis, 34(2) (2024), 10 p., DOI.

2023

→ V. Arora, S. Ponnusamy, S. K. Sahoo, T. Sugawa, "Successive coefficients for functions in the spirallike family", Bulletin des Sciences Mathématiques, 188 (2023), 103323, 15 p., DOI.

→ H. Deng, S. Ponnusamy, J. Qiao, Y. Tian, "On Harmonic Entire Mappings II", Monatsh. Math., 201(4) (2023), 1059–1092, DOI.

→ Y. Huang, M.-S. Liu, S. Ponnusamy, "The Bohr-type operator on analytic functions and sections", Complex Var. Elliptic Equ., 68(2) (2023), 317–332, DOI.

→ R.-Y. Lin, M.- S. Liu, S. Ponnusamy, "Generalization of Bohr-type inequality in analytic functions", Acta Mathematica Sinica, Chinese Series 66(3) (2023), 455–474, DOI.

→ J. Liu, S. Ponnusamy, H. Xie, "Complex symmetric weighted Composition-Differentiation Operators", Linear and Multilinear Algebra 71(5) (2023), 737–755, DOI.

→ H. Xie, J. Liu, S. Ponnusamy, "Volterra type operators on the minimal Moebius invariant space", Canadian Mathematical Bulletin 66(2)(2023), 509–524, DOI.

→ Q. Zhou, Y. He, S. Ponnusamy, Q. Luo, "Egg-Yolk principle for uniformizing Gromov hyperbolic domains", Bulletin des Sciences Mathématiques, 188 (2023), 103333, 23 p., DOI.

→ Q. Zhou, L. Li, X. Li, S. Ponnusamy, "Boundary properties of Gromov hyperbolic H\"older domains", Acta Mathematica Sinica, Chinese Series, 65(4) (2023), 651–662, DOI.

→ G. Liu, S. Ponnusamy, "Improved Bohr inequality for harmonic mappings", Mathematische Nachrichten, 296 (2023), 716–731, DOI.

→ P. Li, Y. Li, Q. Luo, S. Ponnusamy, "On Schwarz–Pick-Type Inequality and Lipschitz Continuity for Solutions to Nonhomogeneous Biharmonic Equations", Mediterranean Journal of Mathematics, 20:3 (2023), 142, DOI.

→ T. Guan, B. Jiao, S. Ponnusamy, Y. He, "Quasisymmetry of freely quasiconformal mappings in Banach spaces", Journal of Mathematical Analysis and Applications, 526 (2023), 127335, DOI.

→ H. Deng, J. Qiao, S. Ponnusamy, Y. Tian, "On harmonic entire mappings II", Monatshefte für Mathematik, 201:4 (2023), 1059–1092, DOI.

→ Q. Zhou, L. Li, S. Ponnusamy, Y. He, "Relatively quasimöbius mappings in Banach spaces", Proc. Amer. Math. Soc., 2023, DOI.

→ L. Li, S. Ponnusamy, K.-J. Wirths, "An Elementary Counterexample to a Coefficient Conjecture", Computational Methods and Function Theory, 2023, 1–11, DOI.

→ K. Chen, MS. Liu, S. Ponnusamy, "Bohr-Type Inequalities for Unimodular Bounded Analytic Functions", Results in Mathematics, 78:5 (2023), 183, DOI.

→ G. Liu, S. Ponnusamy, V. V. Starkov, "Stable classes of harmonic mappings", Bulletin des Sciences Mathématiques, 184 (2023), 103256, DOI.

→ R.-Y. Lin, M.-S. Liu, S. Ponnusamy, "The Bohr-type inequalities for holomorphic mappings with lacunary series in several complex variables", Acta Mathematica Scientia, 44B(1) (2023), 63–79, DOI.

→ Q. Zhou, S. Ponnusamy, "Gromov hyperbolicity in the free quasiworld. I", Studia Mathematica 268 (2023), 23–49, DOI.

2022

→ V. Bravo, R. Hernandez, S. Ponnusamy, O. Venegas, "Pre-Schwarzian and Schwarzian derivatives of logharmonic mappings", Monatsh. Math. 199(2022), 733–754, DOI.

→ Sh. Chen, S. Ponnusamy, "Koebe type theorems and pre-Schwarzian of K-quasiconformal harmonic mappings, and their applications", Acta Mathematica Sinica, English Series (2022), 16 pp., DOI.

→ H. Deng, S. Ponnusamy, J. Qiao, Y. Shan, "On harmonic entire mappings", Rev. R. Acad. Cienc. Exactas Fís Nat. Ser. A Mat. RCSAM (2022), 116:3, 21 pp., DOI.

→ T. Guan, S. Ponnusamy, Q. Zhou, "A note on \(\partial\)-bilipschitz mappings in quasiconvex metric spaces", Bulletin des Sciences Mathématiques, 176 (2022), Article 103128; 19 pp., DOI.

→ P. Hasto, S. Ponnusamy, "A proof of Hall's conjecture on length of ray images under starlike mappings of order \(\alpha\)", Annales Fennici Mathematici 47(2022), 335–349, DOI.

→ I. R. Kayumov, D.M. Khammatova, S. Ponnusamy, "The Bohr inequality for the generalized Cesáro averaging operators", Mediterr. J. Math. 19, 19 (2022), 16 pp., DOI.

→ L. Li, S. Ponnusamy, K.-J. Wirths, "Relations of the class \(U(\lambda)\) to other families of functions", Bull. Malays. Math. Sci. Soc 45 (3) (2022), 955–972, DOI.

→ P. Li, Q. Luo, S. Ponnusamy, "Schwarz-Pick and Landau type theorems for the solutions to Dirichlet-Neumann problem in the unit disk", Comput. Methods Funct. Theory 22(2022), 95–113, DOI.

→ P. Li, S. Ponnusamy, "Lipschitz continuity of quasiconformal solutions of the non-homogeneous Yukawa equations", Analysis and Mathematical Physics 12 (9) (2022), 15 pp., DOI.

→ P. Li, S. Ponnusamy, "Bi-Lipschitz continuity of quasiconformal solutions to a biharmonic Dirichlet-Neumann problem in the unit disk", The Journal of Geometric Analysis 32 (170) (2022), 30 pp., DOI.

→ Y. Li, S. Ponnusamy, Q. Zhou, "Sphericalization and flattening preserve uniform domains in non-locally compact metric spaces", J. Aust. Math. Soc. 112 (2022), 68–89, DOI.

→ J. Liu, S. Ponnusamy, H. Xie, "Complex symmetric weighted Composition-Differentiation Operators", Linear and Multilinear Algebra (2022), 19 pp., DOI.

→ M.- S. Liu, S. Ponnusamy, "Bloch and Landau type theorems for pluriharmonic mappings", International Journal of Mathematics 33(7) (2022), 2250053, DOI.

→ X.-S. Ma, S. Ponnusamy, T. Sugawa, "Harmonic spirallike and harmonic strongly starlike functions", Monatsh. Math. 199 (2022), 363–375, DOI.

→ S. Ponnusamy, R. Vijayakumar, K.-J. Wirths, "Improved Bohr's phenomenon in quasi-subordination classes", Journal of Mathematical Analysis and Applications 506 (1) 2022), 125645, DOI.

→ H. Xie, J. Liu, S. Ponnusamy, "Volterra type operators on the minimal Moebius invariant space", Canadian Mathematical Bulletin (2022), 16 pp., DOI.

→ Q. Zhou, S. Ponnusamy, T. Guan, "Gromov hyperbolicity of the \(j_G\) metric and boundary correspondence", Proc. Amer. Math. Soc. 150(7) (2022), 2839–2847, DOI.

→ Q. Zhou, X. Li, S. Ponnusamy, Y. Li, "Sphericalization and flattening in quasi-metric measure spaces", Journal of Mathematical Analysis and Applications 516(1)(2022), 126496; 23 pp., DOI.

2021

→ Sh. Chen, S. Ponnusamy, X. Wang, "Remarks on Norm estimates of the partial derivatives for harmonic mappings an harmonic quasiregular mappings", The Journal of Geometric Analysis 31 (2021), 11051–11060, DOI.

→ H. Deng, S. Ponnusamy, J. Qiao, "Extreme points and support points of families of harmonic Bloch mappings", Potential Analysis 55 (2021), 619–638, DOI.

→ S. Evdoridis, S. Ponnusamy, A. Rasila, "Improved Bohr's inequality for shifted disks", Results in Mathematics 76:14 (2021), 15 pp., DOI.

→ T. Guan, M. Huang, S. Ponnusamy, X. Wang, "Coarsely bilipschitz continuity of inversions with respect to distance ratio metrics in metric spaces", Results in Mathematics, 76:50 (2021), 13 pp., DOI.

→ T. Guan, M. Huang, S. Ponnusamy, X. Wang, "Quasiisometric mappings in the distance ratio metric in Banach spaces", Monatsh. Math 195(2) (2021), 249–265, DOI.

→ Y. Huang, M.- S. Liu, S. Ponnusamy, "Bohr-type inequalities for harmonic mappings with a multiple zero at the origin", Mediterr. J. Math. 18, 75 (2021), 22 pp., DOI.

→ A. Ismagilov, I. Kayumov, S. Ponnusamy, "Bohr inequalities in some classes of analytic functions", J. Math. Sci., 252(3)(2021), 360–373; Russian translation in Itogi Nauki Tekh. Ser. Sovrem. Mat. Prilozh. Temat. Obz., 153, Complex analysis (Russian), 69–83, Vseross. Inst. Nauchn. i Tekhn. Inform. (VINITI), Moscow, 2018, DOI.

→ I. R. Kayumov, D.M. Khammatova, S. Ponnusamy, "Bohr-Rogosinski phenomenon for analytic functions and Cesaro operators", J. Math. Anal. and Appl., 496(2) (2021), 124824, DOI.

→ G. Liu, Z. H. Liu, S. Ponnusamy, "Refined Bohr inequality for bounded analytic functions", Bulletin des Sciences Mathématiques, 173(2021), 103054, DOI.

→ M.- S. Liu, S. Ponnusamy, "Multidimensional analogues of refined Bohr's inequality", Proc. Amer. Math. Soc. 149(3) (2021), 2133–2146, DOI.

→ Q. Luo, S. Ponnusamy, "One parameter family of univalent polyharmonic mappings", Bull. Malays. Math. Sci. Soc. 44(2021), 839–856, DOI.

→ S. Ponnusamy, T. Sugawa, "Sharp inequalities for logarithmic coefficients and their applications", Bulletin des Sciences Mathématiques, 166(2021), 102931, DOI.

→ S. Ponnusamy, R. Vijayakumar, "Generalized versions of Lipschitz conditions on the modulus of holomorphic functions", C. R. Math. Acad. Sci. Paris 359(5) (2021), 609–615, DOI.

→ S. Ponnusamy, R. Vijayakumar, K.-J. Wirths, "Modifications of Bohr's inequality in various settings", Houston Journal of Mathematics 47(4)(2021), 807–831.

2020

→ S.A. Alkhaleefah, I R. Kayumov, S. Ponnusamy, "Bohr-Rogosinski inequalities for bounded analytic functions", Lobachevskii Journal of Mathematics 41(11)(2020), 2110–2119.

→ Sh. Chen, S. Ponnusamy, "On certain quasiconformal and elliptic mappings", J. Math. Anal. and Appl., 486(2)(2020), 123920.

→ H. Deng, S. Ponnusamy, J. Qiao, "Properties of normal harmonic mappings", Monatsh. Math. 193(3)(2020), 605–621.

→ Y. Huang, M.- S. Liu, S. Ponnusamy, "Refined Bohr-type inequalities with area measure for bounded analytic functions", Anal. Math. Phys. 10, 50 (2020), 21 pp., DOI.

→ M. Huang, S. Ponnusamy, J. Qiao, "Extreme points and support points of harmonic alpha-Bloch Mappings", Rocky Mountain J. Math. 50(4)(2020), 1323–1354.

→ A. Ismagilov, I. Kayumov, S. Ponnusamy, "Sharp Bohr type inequality", J. Math. Anal. and Appl., 489 (1)(2020), 124147, DOI.

→ I. R. Kayumov, D.M. Khammatova, S. Ponnusamy, "On the Bohr inequality for the Cesaro operator", C. R. Math. Acad. Sci. Paris 358(5)(2020), 615–620.

→ I. R. Kayumov, S. Ponnusamy, A. S. Kaliraj, "Riesz-Fej'er inequalities for harmonic functions", Potential Analysis 52(2020), 105–113.

→ S.K. Lee, S. Ponnusamy, K.-J. Wirths, "On classes of meromorphic locally univalent functions defined by differential inequalities", Bulletin of the Iranian Mathematical Society 46(2020), 149–158.

→ G. Liu, and S. Ponnusamy, "Finite pairs of prescribed cycles of Konig's and Steffensen's methods for entire functions", J. Comput. Appl. Math. 368(2020), 112549.

→ M. S. Liu, S. Ponnusamy, J. Wang, "Bohr's phenomenon for the classes of Quasi-subordination and \(K\)-quasiregular harmonic mappings", Rev. R. Acad. Cienc. Exactas Fís. Nat. Ser. A Mat. RACSAM 114 (3) (2020), 115, 15 pp., DOI.

→ P. Muthukumar, S. Ponnusamy, "Composition operators on Hardy spaces of the homogenous rooted trees", Monatsh. Math. 192(2020), 721–743.

→ S. Ponnusamy, N.L. Sharma, K.-J. Wirths, "Logarithmic coefficients problems in families related to starlike and convex functions", J. Aust. Math. Soc. 109(2)(2020), 230–249.

→ S. Ponnusamy, R. Vijayakumar, K.-J. Wirths, "New inequalities for the coefficients of unimodular bounded functions", Results in Mathematics (2020), 75:107, 11 pp., DOI.

→ S. Ponnusamy, K.-J. Wirths, "Bohr type inequalities for functions with a multiple zero at the origin", Comput. Methods Funct. Theory 20(2020), 559–570, DOI.