Gravitational-wave (GW) signals in the microhertz (μHz) frequency range offer a unique window into both astrophysical and cosmological phenomena, yet their origin remains debated. Lunar Laser Ranging (LLR) detectors, which monitor the Earth-Moon orbital resonance, provide a precise method to distinguish between these sources by probing individual GW events. Leveraging the supermassive black...
The memory burden effect describes how an object's stored information resists its own decay. I will show how this mechanism can halt Hawking evaporation and dynamically stabilize black holes against complete decay. Importantly, the phenomenon is not exclusive to gravity: it can arise in generic quantum many-body systems and renormalizable field theories, underscoring its broader theoretical...
What was the Big Bang? Everybody knows (better, thinks to know!). The most widespread (and erroneous) belief is that it was a colossal explosion that took place at the very beginning of the cosmos, and that it launched all the matter and energy concentrated (or “shrunken”) in a “primordial atom” --of unbelievable density and temperature-- into all regions of the universe. It is an enormous...
The inevitable galaxy mergers and the existence of massive black holes (>1e5 Msun) at the centre of most galaxies suggests that galaxies may harbour more than one MBH. After a galaxy merger, two MBHs can eventually get sufficiently close to interact gravitationally and form a massive black hole binary (MBHB). According to general relativity, MBHBs emit gravitational waves (GWs) at different...
