Wyller, John Andreas

Professor

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Phone: +47-6496-5489

Present position: Professor in Applied Mathematics (Norwegian University of Life Sciences, UMB).

Degrees: Ph.D in Applied Mathematics at the University of Tromsø, Norway, 1985, Docent in Applied Mathematics at Luleå University of Technology, Sweden, 1991.

Professional background: Ph.D candidate and Lecturer in Mathematics at University of Tromsø (1982 – 1985); Senior lecturer and Researcher in Applied Mathematics at Luleå University (1986 – 1990); Associate Professor in Mathematics at Narvik University College (1990 – 1997); Associate Professor in Applied Mathematics at the Department of Mathematical Sciences, Agricultural University of Norway (1997 – 1998); Professor at the Department of Mathematical Sciences, Agricultural University of Norway (1998 – 2003); Professor at the Department of Mathematical Sciences and Technology, Agricultural University of Norway (2003 – 2004); Professor at the Department of Mathematical Sciences and Technology, UMB (2005 -).

Current research activity: Nonlinear dynamical systems with applications to optics, biological physics and population dynamics. Particular emphasis om non-local spatial (“long–range interactions”) and/or temporal effects, stability theory, perturbation methods and pattern forming processes.    

Relevant recent activity:   Researcher in computational biology at UMB. Involved in two eVITA programmes (eNEURO - multilevel neural simulation and modelling, project leader Prof. Gaute Einevoll) and (Bridging the gap: disclosure, understanding and exploitation of the genotype-phenotype mapping, project leader Prof. Stig Omholt). Supervisor of several master- and PhD students in applied mathematics at UMB. Extensive international collaboration with researchers from different countries (Sweden, Cameron. Denmark, Australia, Russia).

Selected publications:

  • Wyller J (2001). Nonlinear wavefields in optical fibres with finite time response and amplification effects. Physica D, 157:  90 – 111.
  • Wyller J et al. (2001). Mathematical properties of the rotational diffusion equations, Journal of Physics A:  Mathematical and General. 34: 6531 – 6542.
  • Krolikowski W  et al. (2001) Modulational instability in nonlocal nonlinear Kerr media. Phys. Rev. E  64: 016612.1 -016612.8.
  • Bang O et al. (2002). Collapse arrest and soliton stabilization in nonlocal nonlinear media. Phys. Rev. E 66:  046619.1-046619.5.
  • Pedersen TG et al. (2002).  DC – and AC electro – optic response of chromophores in a viscoelastic polymer matrix: analytical model. Journal of Optical Society of America B: 2622 – 2631. 
  • Wyller J et al. (2002). Generic features of modulational instability in a nonlocal Kerr media. Phys. Rev. E. 66: 066615-1 – 066615 –13.
  • Krolikowski W et al. (2003). Optical beams in nonlocal nonlinear media.  Acta Phys. Pol. A: 103 ,133 – 147.
  • Krolikowski W et al.  (2004). Modulational instability, solitons and beam propagation in spatially nonlocal nonlinear media. J. Opt. B: 6 , S288 - S294.
  • Krolikowski W et al. (2004). Nonlocal incoherent solitons. Phys. Rev. E 70: 036617 - 036622.
  • Blomquist P et al. (2005).  Localized activity patterns in two-population neuronal networks. Physica D 206: 180-212. 
  • Krolikowski W et al. (2005). Modulational instability in generalized nonlinear optical media.  "Focus on Lasers and Electro-Optics Research", F. Columbus, Ed. Nova Science
  • Wyller J et al. (2007). Turing instability and pattern formation in a two-population neuronal network model. Physica D 225: 75 – 93.
  • Wyller J et al. (2007). On the origin and properties of two-population neural field models – a tutorial introduction. Biophysical Reviews and Letters: 2, 1, 79 – 98.
  • Wyller J et al. (2007). Modulational instability in the nonlocal χ(2)  - model. Physica D  227: 8 – 25.
  • Nordbø Ø et al. (2007) Neural network firing-rate models on integral form. Effects of temporal coupling kernels on equilibrium-state stability. Biological Cybernetics 3: 195 - 209.
  • Rotabakk BT et al (2008) A mathematical method for determining equilibrium gas composition in Modified Atmosphere Packaging and Soluble Gas Stabilization systems for non respiring foods. Journal of Food Engineering 85:  479 – 490.
  • Anna Oleynik and John Wyller: Stability of Bumps in a Two Population Neural Field Model, AIP Conference Proceedings Volume 1048 pp. 407—410 NUMERICAL ANALYSIS AND APPLIED MATHEMATICS: International Conference on Numerical Analysis and Applied Mathematics 2008 (ICNAAM2008), ISBN: 978-0-7354-0576-9
  • Anna Oleynik, John Wyller and Igor Wertgeim, The weakly nonlocal limit of a one-population Wilson - Cowan model, AIP Conference Proceedings Volume 1168, pp. 343 – 345, NUMERICAL ANALYSIS AND APPLIED MATHEMATICS: International Conference on Numerical Analysis and Applied Mathematics 2009, ISBN: 978-0-7354-0709
  • John Wyller, Nils Svanstedt and Hubert Nnang, A note on conservation laws for the singularly perturbed χ(2)- model and the corresponding nonlocal χ(2)- approximation. Accepted for publication in ELECTRONIC JOURNAL OF DIFFERENTIAL EQUATIONS (EJDE). 2008.
  • Nils Svanstedt, Hubert Nnang and John Wyller, Two-scale asymptotics and modulational instability for the χ(2) - system in nonlinear optics. Accepted for publication in ELECTRONIC JOURNAL OF DIFFERENTIAL EQUATIONS (EJDE). 2008.