How real detector thresholds create false standard candles

امیر شاه مرادی

 پژوھشگاه مھندسی و علوم محاسباتی، دانشگاه تگزاس آستین

Abstract: In a world in which science and technological breakthroughs dominate all aspects of almost every individual human life, scientists and researchers are under an ever increasing pressure to cross and expand the borders of human knowledge. As new discoveries require higher levels of precision and reproducibility, excess workload and hyper-competitive work environments have made researchers more prone to human cognitive biases. Consequently, these biases have led to an ever increasing number of false-positive scientific discoveries in recent years.  In this talk, I present and elaborate on an example of such discoveries from the field of High-Energy Astrophysics and Cosmology. More specifically, I illustrate how the real complex interplay of human cognitive biases, instrumental biases, and incomplete data have led to the creation of false cosmological standard candles from observational properties of the most powerful explosions ever witnessed in the cosmos, known as Gamma-Ray Bursts (GRBs). These cosmological standard candles, have been frequently used over the past decade, although erroneously, to expand the Hubble diagram beyond supernovae data and to constrain Dark Energy’s equation of state.
I present a Bayesian multilevel methodology and careful analysis of GRB data that can remedy or alleviate the aforementioned existing biases in the studies of GRBs as cosmological standard candles. Furthermore, a mathematically rigorous Bayesian framework is presented for comparing different cosmological models against available observational data, and choosing the most appropriate model.

یکشنبه 5 اردیبهشت ماه 1395، ساعت 15:00

    دانشکده فیزیک، طبقه پنجم اتاق 517