But just how does a random walk turn a quasar into a standard candle?
I'd like to understand the statistics behind the paper... But the article just waves a magic wand and glosses over what I consider would be the most interesting part.
The article links to the "damped random walk" paper here: https://arxiv.org/pdf/1312.3966.pdf I had the same question after reading a related article in an earlier thread: https://mander.xyz/post/984213 - wtf do quasars have to do with measuring the rate of flow of time? - but it seems by simply treating the luminosity graph of a quasar over several years as a random walk with some power spectrum (instead of trying to model the turbulence of the accretion disk directly) they were able to pull out best-fit parameters out of the random walk that also happen to be correlated with other physical properties.