Considerations in the Interpretation of Cosmological Anomalies. Issue Volume 10:Issue S306(2014) (1st July 2015)

• Record Type: Journal Article
• Authors: Peiris, Hiranya V.
• Editors: Heavens, A. F.; Starck, J.-L.; Krone-Martins, A.
• Is Part Of: Proceedings of the International Astronomical Union. Volume 10:Issue S306(2014)
• Page Start: 124
• Page End: 130
• Publication Date: 2015-07-01
• Subjects: cosmic microwave background, -- cosmological parameters, -- early universe, -- cosmology: miscellaneous, -- methods: statistical, -- methods: data analysis; Astronomy -- Congresses; Astronomy -- Periodicals; 520
• DOI: 10.1017/S1743921314011132
• Languages: English
• ISSNs: 1743-9213

Abstract

Abstract: Anomalies drive scientific discovery – they are associated with the cutting edge of the research frontier, and thus typically exploit data in the low signal-to-noise regime. In astronomy, the prevalence of systematics –- both "known unknowns" and "unknown unknowns" – combined with increasingly large datasets, the widespread use of ad hoc estimators for anomaly detection, and the "look-elsewhere" effect, can lead to spurious false detections. In this informal note, I argue that anomaly detection leading to discoveries of new physics requires a combination of physical understanding, careful experimental design to avoid confirmation bias, and self-consistent statistical methods. These points are illustrated with several concrete examples from cosmology.