Simon Fraser University
SFU Cosmology Seminars

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Tuesday, 10 March 2009, 14:00 in P8445A

Prof. Phil Gregory (UBC)

Mining for extra-solar planets with a Bayesian MCMC Kepler periodogram

Are we on the threshold of discovering life elsewhere in the universe? With the mounting discoveries of extra-solar planets there is a sense that we are well underway. Astronomers searching for the small signals induced by planets inevitably face significant statistical challenges. This talk illustrates how a Bayesian re-analysis of published radial velocity data sets is providing strong evidence for additional planetary candidates. The Bayesian nonlinear model fitting is accomplished with a new hybrid Markov chain Monte Carlo (HMCMC) algorithm which incorporates parallel tempering, simulated annealing and the genetic algorithm. Each of these components facilitate the detection of a global minimum in χ2. By combining all three, the HMCMC greatly increase the probability of realizing this goal in a blind search of the parameter space. When applied to the Kepler problem it acts as a powerful multi-planet Kepler periodogram for both parameter estimation and model selection. The algorithm is embedded in a unique two stage adaptive control system that automates the tuning of the MCMC proposal distribution parameters through an annealing operation. The HMCMC algorithm is very general and applicable to many other nonlinear model fitting problems.

Seminars in 2008:

2008-09-25 14:00 in IRMACS - Dmitri Korotkin (Concordia University): Canonical quantization of Einstein-Rosen gravitational waves with two polarizations
2008-10-02 14:00 in IRMACS - Andrei Frolov (SFU): A singularity problem with f(R) dark energy
2008-11-14 14:30 in AQ3181 - Robert Brandenberger (McGill University): String theory and the very early universe (physics colloquium)
2009-01-23 14:30 in P8445B - Fotini Markopoulou (Perimeter): Two ways to derive a spacetime in quantum gravity
2009-01-27 14:00 in P8445A - Edward Chapin (UBC): Detecting massive star-forming galaxies at z>1 using BLAST and SCUBA-2 submillimetre wavelength surveys
2009-02-03 14:00 in P8445A - Subinoy Das (UBC): Late forming dark matter
2009-02-20 14:30 in AQ3182 - Mark Trodden (Syracuse University): Gravitational approaches to cosmic acceleration (physics colloquium)
2009-02-24 14:00 in P8445A - Adam Ritz (University of Victoria): Probing pseudoscalar perturbations with CMB polarization
2009-03-03 14:00 in P8445A - John Ward (University of Victoria): Gravitational wave constraints on multi-brane inflation
2009-03-10 14:00 in P8445A - Phil Gregory (UBC): Mining for extra-solar planets with a Bayesian MCMC Kepler periodogram
2009-03-27 14:30 in AQ3182 - Suzanne Staggs (Princeton University): The impact of the last 13 billion years and of the first 10-35 seconds on the CMB (physics colloquium)
2009-05-05 14:00 in P8445B - Justin Khoury (University of Pennsylvania): Cascading gravity
2009-07-21 14:00 in P8445B - Daniele Steer (APC, Paris): Multi-field DBI inflation: primordial perturbations and non-Gaussianities

[ See complete seminar archives | iCal feed ]

Modified by Andrei Frolov <frolov@sfu.ca> on 2023-11-01