Janne Heittokangas

Opiskelun joustavuuden lisääminen matematiikan yliopisto-opintojen taitekohdassa

Eronen Lasse; Heittokangas Janne. 2022. FMSERA Journal. 5: 61-75

Value distribution of exponential polynomials and their role in the theories of complex differential equations and oscillation theory

Heittokangas, Janne; Ishizaki, Katsuya; Tohge, Kazuya; Wen, Zhi‐Tao. 2022. Bulletin of the london mathematical society. 2023; 55: 1-77

Contour integral solutions of linear differential equations which include a generalization of the Airy integral

Gundersen, Gary G; Heittokangas, Janne M; Wen, Zhi-Tao. 2021. Houston journal of mathematics. 47: 321–351

Complex oscillation and nonoscillation results

Heittokangas, Janne; Ishizaki, Katsuya; Laine, Ilpo; Tohge, Kazuya. 2019. Transactions of the american mathematical society. 372: 6161-6182

Zero distribution and division results for exponential polynomials

Heittokangas, Janne; Ishizaki, Katsuya; Tohge, Kazuya; Wen, Zhi-Tao. 2018. Israel journal of mathematics. 227: 397-421

Dual exponential polynomials and linear differential equations

Wen Zhi-Tao, Gundersen Gary G, Heittokangas Janne. 2017. Journal of differential equations. 2018; 264: 98-114

On the relationship between the lower order of coefficients and the growth of solutions of differential equations

Long Jianren, Heittokangas Janne, Ye Zhuan. 2016. Journal of mathematical analysis and applications. 444: 153-166

Completely regular growth solutions of second order complex linear differential equations

Heittokangas Janne, Laine Ilpo, Tohge Kazuya, Wen Zhi-Tao. 2015. Annales academiae scientiarum fennicae-mathematica. 40: 985-1003

Second-order complex linear differential equations with special functions or extremal functions as coefficients

Wu Xiubi, Long Jianren, Heittokangas Janne, Qiu Ke-e. 2015. Electronic journal of differential equations. 2015: 1-15

Functions of finite logarithmic order in the unit disc, Part I

Heittokangas Janne, Wen Zhi-Tao. 2014. Journal of mathematical analysis and applications. 415: 435-461

Functions of finite logarithmic order in the unit disc, Part II

Heittokangas Janne, Wen Zhi-Tao. 2014. Computational methods and function theory. -: 1-22

On alpha-Polynomial Regular Functions, with Applications to Ordinary Differential Equations

Fenton Peter, Gröhn Janne, Heittokangas Janne, Rossi John, Rättyä Jouni. 2014. Proceedings of the Edinburgh Mathematical Society. 57: 405-421

On the complexity of finding a necessary and sufficient condition for Blaschke-oscillatory equations

Heittokangas Janne, Reijonen Atte. 2014. Glasgow mathematical journal. -: 1-12

Zero separation results for solutions of second order linear differential equations

Chuaqui Martin, Gröhn Janne, Heittokangas Janne, Rättyä Jouni. 2013. Advances in mathematics. 245: 382-422

Blaschke Products and Their Applications

Grudsky Sergei, Shargorodsky Eugene, Gauthier Paul, Heittokangas Janne, Boivin Andre, Zhu Changzhong, Mashreghi Javad, Cima Joseph, Pfaltzgraff John, Kraus Daniela, Roth Oliver, Chyzhykov Igor, Skaskiv Severyn, Gluchoff Alan, Hartmann Frederick, Baribeau Line, Feichtinger Hans, Pap Margit, Martin Maria, Vukotic Dragan et al.. Teoksessa: Javad Mashreghi, Emmanuel Fricain(toim.) , 2012. A survey on Blaschke-oscillatory differential.... s. 43-98. Springer

Exponential polynomials as solutions of certain nonlinear difference equations

Wen Zhi Tao, Heittokangas Janne, Laine Ilpo. 2012. Acta mathematica sinica : english series. 28: 1295-1306

New Findings on the Bank-Sauer Approach in Oscillation Theory

Gröhn Janne, Heittokangas Janne. 2012. Constructive approximation. 35: 345-361

Sharp logarithmic derivative estimates with applications to ordinary differential equations in the unit disc

I. Chyzhykov, J. Heittokangas, J. Rättyä. 2010. Journal of the australian mathematical society. 88: 145-167

Finiteness of &phi: order of solutions of linear differential equations in the unit disc

I. Chyzhykov, J. Heittokangas, J. Rättyä. 2009. Journal d'analyse mathématique. 109: 163-198

Growth estimates for solutions of nonhomogeneous linear complex differential equations

Janne Heittokangas, Risto Korhonen ja Jouni Rättyä. 2009. Annales academiae scientiarum fennicae-mathematica. 34: 145-156

Value sharing results for shifts of meromorphic functions, and sufficient conditions for periodicity

J. Heittokangas, R. Korhonen, I. Laine, J. Rieppo, J. Zhang. 2009. Journal of mathematical analysis and applications. 355: 352-363

Linear differential equations with coefficients in weighted Bergman and Hardy spaces

Janne Heittokangas, Risto Korhonen, Jouni Rättyä. 2008. Transactions of the american mathematical society. 360: 1035-1055

Growth estimates for logarithmic derivatives of Blaschke products and of functions in the Nevanlinna class

Janne Heittokangas. 2007. Kodai Mathematical Journal. 30: 263-279

Linear differential equations with solutions in Dirichlet type subspace of the Hardy space

J. Heittokangas, R. Korhonen, J. Rättyä. 2007. Nagoya Mathematical Journal. 187: 91-113

Blaschke-oscillatory equations of the form f''+A(z)f=0

Janne Heittokangas. 2006. Journal of mathematical analysis and applications. 318: 120-133

Fast growing solutions of linear differential equations in the unit disc

Janne Heittokangas, Risto Korhonen, Jouni Rättyä. 2006. Results in mathematics. 49: 265-278

Solutions of f''+A(z)f=0 in the unit disc having Blaschke sequences as the zeros

Janne Heittokangas. 2005. Computational methods and function theory. 5: 49-63

Solutions of f''+A(z)f=0 with prescribed sequences of zeros

J. Heittokangas, I. Laine. 2005. Acta Mathematica Universitatis Comenianae. 74: 287-307

Generalized logarithmic derivative estimates of Gol'dberg-Grinshtein type

J. Heittokangas, R. Korhonen, J. Rättyä. 2004. Bulletin of the london mathematical society. 36: 105-114

Growth estimates for solutions of linear complex differential equations

J. Heittokangas, R. Korhonen, J. Rättyä. 2004. Annales academiae scientiarum fennicae-mathematica. 29: 233-246

Symposium on Complex Differential and Functional Equations

Rauno Aulaskari, Janne Heittokangas, Visa Latvala, Jari Taskinen (eds.). 2004. University of Joensuu, Department of Mathematics. Report Series. . Joensuun yliopisto

Linear differential equations and logarithmic derivative estimates

Igor Chyzhykov, Gary G. Gundersen, Janne Heittokangas. 2003. Proceedings of the london mathematical society. 86: 735-754

Meromorphic solutions of generalized Schröder equations

Gary G. Gundersen, Janne Heittokangas, Ilpo Laine, Jarkko Rieppo, Dequi Yang. 2002. Aequationes mathematicae. 63: 110-135

On meromorphic solutions of certain nonlinear differential equations

J. Heittokangas, R. Korhonen, I. Laine. 2002. Bulletin of the australian mathematical society. 66: 331-343

Complex difference equations of Malmquist type

Janne Heittokangas, Risto Korhonen, Ilpo Laine, Jarkko Rieppo, Katsuya Tohge. 2001. Computational methods and function theory. 1: 27-39

Differential equations with Hadamard products and Ruscheweyh derivatives

Janne Heittokangas. 2000. Mathematical Reports. 2(52): 467-484

Meromorphic solutions of some linear functional equations

Janne Heittokangas, Ilpo Laine, Jarkko Rieppo, Degui Yang. 2000. Aequationes mathematicae. 60: 148-166

On complex differential equations in the unit disc

Janne Heittokangas. 2000. Annales Academiae Scientiarum Fennicae. Mathematica. Dissertationes

Tarkenna hakuasi

Tutkimusryhmät

A Continuous Transition from E-Sets to R-sets and Beyond

Description of growth and oscillation of solutions of complex LDE’s

Irregular finite order solutions of complex LDE's in unit disc

Opiskelun joustavuuden lisääminen matematiikan yliopisto-opintojen taitekohdassa

Value distribution of exponential polynomials and their role in the theories of complex differential equations and oscillation theory

Contour integral solutions of linear differential equations which include a generalization of the Airy integral

Complex oscillation and nonoscillation results

Zero distribution and division results for exponential polynomials

Dual exponential polynomials and linear differential equations

On the relationship between the lower order of coefficients and the growth of solutions of differential equations

Completely regular growth solutions of second order complex linear differential equations

Second-order complex linear differential equations with special functions or extremal functions as coefficients

Functions of finite logarithmic order in the unit disc, Part I

Functions of finite logarithmic order in the unit disc, Part II

On alpha-Polynomial Regular Functions, with Applications to Ordinary Differential Equations

On the complexity of finding a necessary and sufficient condition for Blaschke-oscillatory equations

Zero separation results for solutions of second order linear differential equations

Blaschke Products and Their Applications

Exponential polynomials as solutions of certain nonlinear difference equations

New Findings on the Bank-Sauer Approach in Oscillation Theory

Sharp logarithmic derivative estimates with applications to ordinary differential equations in the unit disc

Finiteness of &phi: order of solutions of linear differential equations in the unit disc

Growth estimates for solutions of nonhomogeneous linear complex differential equations

Value sharing results for shifts of meromorphic functions, and sufficient conditions for periodicity

Linear differential equations with coefficients in weighted Bergman and Hardy spaces

Growth estimates for logarithmic derivatives of Blaschke products and of functions in the Nevanlinna class

Linear differential equations with solutions in Dirichlet type subspace of the Hardy space

Blaschke-oscillatory equations of the form f''+A(z)f=0

Fast growing solutions of linear differential equations in the unit disc

Solutions of f''+A(z)f=0 in the unit disc having Blaschke sequences as the zeros

Solutions of f''+A(z)f=0 with prescribed sequences of zeros

Generalized logarithmic derivative estimates of Gol'dberg-Grinshtein type

Growth estimates for solutions of linear complex differential equations

Symposium on Complex Differential and Functional Equations

Linear differential equations and logarithmic derivative estimates

Meromorphic solutions of generalized Schröder equations

On meromorphic solutions of certain nonlinear differential equations

Complex difference equations of Malmquist type

Differential equations with Hadamard products and Ruscheweyh derivatives

Meromorphic solutions of some linear functional equations

On complex differential equations in the unit disc