**4.2. Equivalence between stability methods**

Floquet exponents, Lyapunov exponents and characteristic multipliers are interconnected to each other. Mathematical expressions to relate each approach are synthesized in figure 5. For example, we can compute the Floquet exponents (*μi*) for any delay and later we can apply the relations *mi* = *eμiT* and *λ<sup>i</sup>* = *μiT* to find characteristic multipliers and Lyapunov exponents, respectively.

Figure 6 shows the evolution of Floquet and Lyapunov exponents when the duty cycle is computed without delay and with one delay. The critic values are the equals using any method. Therefore, both methods give the same information.

Figure 7 shows the evolution of Floquet exponents and characteristic multipliers in the complex plane of each representation. In both cases, the parameter *N* is varied in the range [0; 30] with *ks* = 4.5 and *τ* = 1. Imaginary axis is the stability limit of the Floquet exponents locus, while unity circle is the stability limit of the characteristic multipliers locus.
