My name is Sebastiaan Janssens. I am working on finishing my PhD in mathematics with O. Diekmann, S.A. van Gils and Yu.A. Kuznetsov at Utrecht University and the University of Twente in The Netherlands after being held back by health problems for longer periods of time.

I am interested in rigorous qualitative analysis of dynamical systems or, more specifically,

• ordinary differential equations,

• various classes of delay equations,

• stability and bifurcation of their solutions,

• related linear algebra and functional analysis.

Recently I have also become interested in systems and control theory.

Most of my mathematical posts will feature small observations that do not fit easily in another form of publication. $\LaTeX$ formulas were processed using the QuickLaTeX plugin and, more recently, the MathJax engine. These are both great projects and they each deserve a look.

I have disabled commenting on the posts for anti-spam reasons. If you have a useful comment or addition, please send me an email and I will manually add it – with your name and site, if you like – at the end of the post.

### Contact information

You can send email to [my first and last initial in bold]@dydx.nl. If you want to, you can use my PGP key to encrypt your message.