LISA mission: from the experiment to the potential discoveries

• Francesco Crescimbeni

Gravitational waves detected by the ground-based interferometers LIGO, Virgo and Kagra have opened the way to new scenarios and provided new tools to get a deeper understanding of our universe. One of the most promising ways to detect those signals in the future will be with a detector settled-up in the space known as Laser Interferometer Space Antenna (LISA). In this talk, we will introduce the experimental set-up, as well as its goals and the new potential sources that could detect.

Dicussion

Two-phonon pairing does not explain superconductivity in strontium titanate

• Antonio Santacesaria

The unconventional and antiadiabatic nature of strontium titanate (STO) makes the BCS paradigm not directly applicable. Although experimental evidence indicates a connection between the superconductivity and a ferroelectric quantum critical point, the pairing mechanism is still not known. We study a mechanism mediated by two polar transverse modes associated with the incipient ferroelectric instability. We derive the effective two-phonon mediated electron-electron interaction in the Migdal-Eliashberg formalism, including time dependence and retardation effects. We conclude that the estimated coupling parameter of the two-phonon interaction for STO is too small to reproduce a finite critical temperature.

Discussion