# Exceptional point in a simple textbook example

@article{Fernandez2018ExceptionalPI, title={Exceptional point in a simple textbook example}, author={Francisco M. Fern'andez}, journal={European Journal of Physics}, year={2018}, volume={39}, pages={045005} }

We propose to introduce the concept of exceptional points in intermediate courses on mathematics and classical mechanics by means of simple textbook examples. The first one is an ordinary second-order differential equation with constant coefficients. The second one is the well-known damped harmonic oscillator. From a strict mathematical viewpoint both are the same problem that enables one to connect the occurrence of linearly dependent exponential solutions with a defective matrix which cannot…

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