Research interests: Abstract integral equations and operator semigroups. Integration, duality, and admissibility. Existence, stability, and bifurcation of parameter-dependent equilibria and periodic orbits. Methodological connections with control and economic dynamics.

For my work in mathematics I am kindly hosted by Utrecht University, The Netherlands. My PhD advisers are O. Diekmann and S.M. Verduyn Lunel.

## Contact information

You can contact me via email (can be used with my PGP key) or more email.
I have a profile on ResearchGate.

## Pre-prints and publications

S.G. Janssens, A class of abstract delay differential equations in the light of suns and stars. Part II, March 2020, arXiv:2003.13341 [math.DS, math.FA].
Presentation video and slides about this work for the third installment of the Delay Days, online, 1 October 2020.

M.M. Bosschaert, S.G. Janssens, Yu.A. Kuznetsov, Switching to nonhyperbolic cycles from codimension two bifurcations of equilibria of delay differential equations, March 2019, arXiv:1903.08276 [math.DS]. Accepted for publication in SIAM Journal on Applied Dynamical Systems.

S.G. Janssens, A class of abstract delay differential equations in the light of suns and stars. Part I, January 2019, arXiv:1901.11526 [math.DS, math.FA].
Presentation about this work for a day on Delay equations, theory and applications, Utrecht, 15 February 2019.

K. Dijkstra, S.A. van Gils, S.G. Janssens, Yu.A. Kuznetsov, S. Visser, Pitchfork-Hopf bifurcations in 1D neural field models with transmission delays, Phys. D 297 (2015), 88–101, DOI: 10.1016/j.physd.2015.01.004.

S.A. van Gils, S.G. Janssens, Yu.A. Kuznetsov, S. Visser, On local bifurcations in neural field models with transmission delays, J. Math. Biol. 66 (2013), no. 4-5, 837–887, DOI:10.1007/s00285-012-0598-6 and arXiv:1209.2849 [math.DS].

S.G. Janssens, On a Normalization Technique for Codimension Two Bifurcations of Equilibria of Delay Differential Equations, Master Thesis, Utrecht University, 2010, original or with updates (latest: 20 November 2018).

My master thesis was written under supervision of Yu.A. Kuznetsov with Odo Diekmann as co-supervisor. The updated version contains corrections and some new material – see the Summary of updates and corrections. It is available under a Creative Commons BY-NC-ND 4.0 International license.

## Site credits

I am a grateful user of various high quality programs that are part of the GNU project.
For online $\LaTeX$ formula typesetting with MathJax I use the Simpe MathJax plugin.