From Dark Matter to Cosmology: A journey into gravitational waves physics

• Alessandro Buchicchio

The discovery of Gravitational Waves (GWs), in 2015, marked a turning point in modern physics. It served not only as a further confirmation of the theory of general relativity but, most of all, it introduced a new powerful tool to explore from a new perspective many areas of modern physics. I will first discuss my master’s thesis project, which focuses on the use of gravitational waves to search for ultralight vector boson clouds which are dark matter candidates. I will then move on to my PhD project, focusing on inferring the Hubble constant using dark sirens and galaxy catalogue techniques.

Dicussion

Infrared spectrum as topological marker in finite-size Haldane models

• Andrea Borghi

Topological insulators are materials with an insulating bulk, but in the topological phase presents conductive state on the surface, driven by the metallic edge bands. While characterizing the phase by measuring the surface current is experimentally challenging, recent studies linked the infrared spectrum to the topology, posing as a more practical experimental marker for the phase. To confirm this connection, we studied the Haldane model—the simplest model exhibiting topological behaviour—using a 2D system with a single periodic direction. This geometry allows us to see the topological edge effects on both the system's electronic properties and on its infrared spectrum.

Discussion