Title: New Approach to Periodicity Detection

Abstract:

Periodicity is pervasive in all fields of Astronomy: from rotation of asteroids, 
through transiting exoplanets and pulsating stars, to stellar orbits around the 
Galactic Center. Thus, detecting periodicity in astronomical data, which are 
often sparse and unevenly sampled, has always been a staple of astronomical 
research. Astronomers use an arsenal of methods to perform the task, none of 
them is perfect, and most of them rely on some arbitrary assumptions or 
parameters. The most popular one is the Lomb-Scargle periodogram which 
essentially searches for sinusoidal periodicities. This talk will present a 
novel approach to periodicity detection – the Phase Distance Correlation 
periodogram (PDC) - which is nonparametric, model independent and 
computationally elegant. PDC is an application of some very recent developments 
in statistics, and it opens up new horizons in the field. It can easily be 
extended to detect periodicities of new and unknown types, in various modalities 
of data - photometry, spectroscopy, astrometry and even polarimetry. It can also 
be applied to the problem of radial-velocity detection of exoplanets in the 
presence of interference by stellar activity. The talk will introduce the basic 
ideas of PDC, highlight its novelty, and demonstrate its advantages in some 
types of data.