Thermal noise issue in the monolithic suspensions of the Virgo+ gravitational wave interferometer

From quality factor measurements we can estimate thermal noise using an analytical or numerical model of the physical system and dissipative processes. Moreover, for some resonances, we know the loss mechanisms and the regions where there is the larger deformation during the vibrational motion. In that case, the knowledge of quality factors allows us to understand if there is a further damping process acting on a system component and, when required, to modify its technical design and realization. This is mandatory to correctly design and realize a low-dissipative suspension for a gravitational wave interferometer.