Dr. Vid Iršič: Relativistic effects in Lyman-alpha forest

As the observations move out to larger scales the validity of a simple Newtonian description starts to come into question. Recent years have seen a lot of effort put into understanding and possibly measuring the signal of relativistic effects and/or weak gravitational lensing in the 2-point statistics of the galaxy clustering.
I will present the first study to extend the formalism to a different tracer of underlying matter at unique redshift range (z = 2 − 5). Furthermore, I will show a comprehensive application of the calculations to the Quasar-Lyman-alpha cross-correlation function. The results indicate that the signal of relativistic effects can be as large as 30% at Baryonic Acoustic Oscillation (BAO) scale, which is much larger than anticipated and mainly due to the large differences in density bias factors of our tracers.