JANNE HEITTOKANGAS

Contact info

Research groups - UEF

• 
  Complex Analysis

Publications

• Chyzhykov, I.; Gröhn, J.; Heittokangas, J.; Rättyä, J.. 2022. Oscillation of Solutions of LDE¿s in Domains Conformally Equivalent to Unit Disc Journal of geometric analysis 32 3: 71. 2022
• Yu, Hui; Heittokangas, Janne; Wang, Jun; Wen, Zhi Tao. 2022. Meromorphic Functions of Finite φ-order and Linear Askey-Wilson Divided Difference Equations Acta mathematica sinica : english series 38: 371-383. 2022
• Gundersen, Gary G.; Heittokangas, Janne; Zemirni, Mohamed Amine. 2022. Asymptotic integration theory for f''+ P(z)f=0 Expositiones mathematicae 40 1: 94-126. 2022
• Heittokangas, J; Latreuch, Z; Wang, J; Zemirni, M A. 2021. On meromorphic solutions of non-linear differential equations of Tumura - Clunie type Mathematische nachrichten 294 4: 748-773. 2021
• Heittokangas, J; Wang, J; Wen, ZT; Yu, H. 2021. Meromorphic functions of finite φ-order and linear q-difference equations Journal of difference equations and applications 27 9: 1280-1309. 2021
• Heittokangas, J; Wen, ZT. 2021. The asymptotic number of zeros of exponential sums in critical strips Monatshefte fur mathematik 194 2: 261-273. 2021
• Heittokangas, Janne; Zemirni, Mohamed Amine. 2021. On Petrenko's deviations and second order differential equations Kodai mathematical journal 44 1: 181-193. 2021
• Heittokangas, Janne; Ishizaki, Katsuya; Tohge, Kazuya; Wen, Zhi-Tao. 2021. Dual exponential polynomials and a problem of Ozawa Proceedings of the Royal Society of Edinburgh section A: mathematics [Epub ahead of print 16 June 2021]: 1-19. 2021
• Heittokangas, Janne; Latreuch, Zinelaabidine; Wang, Jun; Zemirni, Amine. 2021. On the limits of real-valued functions in sets involving Ψ-density, and applications Journal of mathematical analysis and applications 507 1: 125787. 2021
• Heittokangas, Janne; Wen, Zhi-Tao. 2020. Generalization of Pólya's Zero Distribution Theory for Exponential Polynomials, and Sharp Results for Asymptotic Growth Computational methods and function theory 2021; 21 2: 245-270. 2020
• Heittokangas, Janne; Yu, Hui; Zemirni, Mohamed Amine. 2020. On the number of linearly independent admissible solutions to linear differential and linear difference equations Canadian journal of mathematics-journal canadien de mathematiques 2021; 73 6: 1556-1591. 2020
• Heittokangas, Janne; Ishizaki, Katsuya; Laine, Ilpo; Tohge, Kazuya. 2020. Exponential polynomials in the oscillation theory Journal of differential equations 272: 911-937. 2020
• Gundersen, Gary G; Heittokangas, Janne; Wen, Zhi-Tao. 2020. Deficient Values of Solutions of Linear Differential Equations Computational methods and function theory 2021; 21 1: 145-177. 2020
• Heittokangas, Janne; Ishizaki, Katsuya; Laine, Ilpo; Tohge, Kazuya. 2019. Complex oscillation and nonoscillation results Transactions of the american mathematical society 372 9: 6161-6182. 2019
• Heittokangas, Janne; Ishizaki, Katsuya; Tohge, Kazuya; Wen, Zhi-Tao. 2018. Zero distribution and division results for exponential polynomials Israel journal of mathematics 227 1: 397-421. 2018
• Wen Zhi-Tao, Gundersen Gary G, Heittokangas Janne. 2017. Dual exponential polynomials and linear differential equations. Journal of Differential Equations 2018; 264 1: 98-114. 2017
• Long Jianren, Heittokangas Janne, Ye Zhuan. 2016. On the relationship between the lower order of coefficients and the growth of solutions of differential equations. JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS 444 1: 153-166. 2016
• Heittokangas Janne, Laine Ilpo, Tohge Kazuya, Wen Zhi-Tao. 2015. Completely regular growth solutions of second order complex linear differential equations. Annales Academiae Scientiarum Fennicae. Mathematica 40: 985-1003. 2015
• Wu Xiubi, Long Jianren, Heittokangas Janne, Qiu Ke-e. 2015. Second-order complex linear differential equations with special functions or extremal functions as coefficients. Electronic Journal of Differential Equations 2015 143: 1-15. 2015
• Fenton Peter, Gröhn Janne, Heittokangas Janne, Rossi John, Rättyä Jouni. 2014. On alpha-Polynomial Regular Functions, with Applications to Ordinary Differential Equations. Proceedings of the Edinburgh Mathematical Society 57 02: 405-421. 2014
• Heittokangas Janne, Reijonen Atte. 2014. On the complexity of finding a necessary and sufficient condition for Blaschke-oscillatory equations. Glasgow Mathematical Journal - -: 1-12. 2014
• Heittokangas Janne, Wen Zhi-Tao. 2014. Functions of finite logarithmic order in the unit disc, Part I. JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS 415 1: 435-461. 2014
• Heittokangas Janne, Wen Zhi-Tao. 2014. Functions of finite logarithmic order in the unit disc, Part II. Computational Methods and Function Theory - -: 1-22. 2014
• Chuaqui Martin, Gröhn Janne, Heittokangas Janne, Rättyä Jouni. 2013. Zero separation results for solutions of second order linear differential equations. Advances in Mathematics 245: 382-422. 2013
• Wen Zhi Tao, Heittokangas Janne, Laine Ilpo. 2012. Exponential polynomials as solutions of certain nonlinear difference equations. Acta Mathematica Sinica 28 7: 1295-1306. 2012
• Gröhn Janne, Heittokangas Janne. 2012. New Findings on the Bank-Sauer Approach in Oscillation Theory. Constructive Approximation 35 3: 345-361. 2012
• 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.. 2012. Blaschke Products and Their Applications: Javad Mashreghi, Emmanuel Fricain, A survey on Blaschke-oscillatory differential.... 43-98. 2012
• Chuaqui Martin, Gröhn Janne, Heittokangas Janne, Rättyä Jouni. 2011. Possible Intervals for T- and M-Orders of Solutions of Linear Differential Equations in the Unit Disc Abstract and Applied Analysis 2011: -. 2011
• Heittokangas J, Korhonen R, Laine I, Rieppo J. 2011. Uniqueness of meromorphic functions sharing values with their shifts COMPLEX VARIABLES AND ELLIPTIC EQUATIONS 56: 81-92. 2011
• Heittokangas Janne, Rättyä Jouni. 2011. Zero distribution of solutions of complex linear differential equations determines growth of solutions. Mathematische Nachrichten 284: 412-420. 2011
• Heittokangas Janne, Tohge Kazuya. 2011. A unit disc analogue of the Bank-Laine conjecture does not hold. Annales Academiae Scientiarum Fennicae. Mathematica 36: 341-351. 2011
• Heittokangas Janne. 2011. On interpolating Blaschke products and Blaschke-oscillatory equations. Constructive Approximation 34: 1-21. 2011
• I. Chyzhykov, J. Heittokangas, J. Rättyä. 2010. Sharp logarithmic derivative estimates with applications to ordinary differential equations in the unit disc. Journal of the Australian Mathematical Society 88 2: 145-167. 2010
• I. Chyzhykov, J. Heittokangas, J. Rättyä. 2009. Finiteness of φ order of solutions of linear differential equations in the unit disc. Journal d'analyse mathématique 109: 163-198. 2009
• J. Heittokangas, R. Korhonen, I. Laine, J. Rieppo, J. Zhang. 2009. Value sharing results for shifts of meromorphic functions, and sufficient conditions for periodicity. Journal of Mathematical Analysis and Applications 355: 352-363. 2009
• Janne Heittokangas, Risto Korhonen ja Jouni Rättyä. 2009. Growth estimates for solutions of nonhomogeneous linear complex differential equations Annales Academiae Scientiarum Fennicae. Mathematica 34: 145-156. 2009
• Janne Heittokangas, Risto Korhonen, Jouni Rättyä. 2008. Linear differential equations with coefficients in weighted Bergman and Hardy spaces Transactions of the American Mathematical Society 360 2: 1035-1055. 2008
• J. Heittokangas, R. Korhonen, J. Rättyä. 2007. Linear differential equations with solutions in Dirichlet type subspace of the Hardy space. Nagoya Mathematical Journal 187: 91-113. 2007
• Janne Heittokangas. 2007. Growth estimates for logarithmic derivatives of Blaschke products and of functions in the Nevanlinna class Kodai Mathematical Journal 30 2: 263-279. 2007
• Janne Heittokangas, Risto Korhonen, Jouni Rättyä. 2006. Fast growing solutions of linear differential equations in the unit disc. Results in Mathematics 49 3/4: 265-278. 2006
• Janne Heittokangas. 2006. Blaschke-oscillatory equations of the form f''+A(z)f=0. Journal of Mathematical Analysis and Applications 318 1: 120-133. 2006
• J. Heittokangas, I. Laine. 2005. Solutions of f''+A(z)f=0 with prescribed sequences of zeros. Acta Mathematica Universitatis Comenianae 74 2: 287-307. 2005
• Janne Heittokangas. 2005. Solutions of f''+A(z)f=0 in the unit disc having Blaschke sequences as the zeros. Computational Methods and Function Theory 5 1: 49-63. 2005
• J. Heittokangas, R. Korhonen, J. Rättyä. 2004. Generalized logarithmic derivative estimates of Gol'dberg-Grinshtein type. Bulletin of the London Mathematical Society 36 1: 105-114. 2004
• J. Heittokangas, R. Korhonen, J. Rättyä. 2004. Growth estimates for solutions of linear complex differential equations. Annales Academiae Scientiarum Fennicae. Mathematica 29 1: 233-246. 2004
• Symposium on Complex Differential and Functional Equations. Rauno Aulaskari, Janne Heittokangas, Visa Latvala, Jari Taskinen (eds.). 2004 2004
• Igor Chyzhykov, Gary G. Gundersen, Janne Heittokangas. 2003. Linear differential equations and logarithmic derivative estimates. Proceedings of the London Mathematical Society 86 3: 735-754. 2003
• Gary G. Gundersen, Janne Heittokangas, Ilpo Laine, Jarkko Rieppo, Dequi Yang. 2002. Meromorphic solutions of generalized Schröder equations. Aequationes mathematicae 63 1-2: 110-135. 2002
• J. Heittokangas, R. Korhonen, I. Laine. 2002. On meromorphic solutions of certain nonlinear differential equations. Bulletin of the Australian Mathematical Society 66 2: 331-343. 2002
• Janne Heittokangas, Risto Korhonen, Ilpo Laine, Jarkko Rieppo, Katsuya Tohge. 2001. Complex difference equations of Malmquist type. Computational Methods and Function Theory 1 1: 27-39. 2001
• Janne Heittokangas, Ilpo Laine, Jarkko Rieppo, Degui Yang. 2000. Meromorphic solutions of some linear functional equations. Aequationes mathematicae 60 1-2: 148-166. 2000
• Janne Heittokangas. 2000. Differential equations with Hadamard products and Ruscheweyh derivatives. Mathematical Reports 2(52) 4: 467-484. 2000
• Janne Heittokangas. 2000. On complex differential equations in the unit disc. Suomalainen tiedeakatemia. Annales Academiae Scientiarum Fennicae. Mathematica. Dissertationes. 2000