The luminosity-variability relation in BASS type-1 AGN connection with physical properties and cosmological implementations

Variability is observed in AGN across all wavelengths, yet the physical mechanisms driving this phenomenon remain not fully understood. It has long been established that variability correlates with certain physical properties of AGN. Specifically, more massive black holes, and thus more luminous AGN, exhibit lower variability. However, the underlying cause of this correlation is still debated, with uncertainty about whether black hole mass, the accretion rate, or a combination of both is the primary driver. In this presentation, I will share results from the luminosity-variability analysis of the BASS sample, which includes type-1 AGN with X-ray excess variance measurements and optical/NIR spectroscopy. I will show the relation between variability and various physical properties of AGN, discussing how these correlations can deepen our understanding of AGN physics and variability mechanisms. Additionally, the correlation between luminosity and variability offers potential forestimating absolute luminosities and thus absolute distances of AGN, enabling their use as standard candles. I will discuss the implications of this approach for cosmology, addressing current limitations and exploring how future surveys like LSST may allow for the estimation of absolute distances through variability.