2022 Events

FI Computational Methods and Data Science Journal Club: Alan Heavens (Imperial)

5th Floor Classroom/5-Flatiron Institute (162 5th Avenue)

5th Floor Classroom/5-Flatiron Institute

162 5th Avenue


FI Computational Methods and Data Science Journal Club
Flatiron Institute, 162 5th Avenue

Speaker: Alan Heavens (Imperial)

Title: Hierarchical Bayesian Models and Simulation-based Inference in Cosmology

Abstract: The context for this talk is cosmology, but the methods described are applicable to a wide range of situations.  I’ll cover our recent work in principled Bayesian methods for handling large datasets for which we have a good underlying  data model (which can be complex).  Cosmic shear is an example where the likelihood can be applied at the field level, without computing lossy summary statistics.  In the process a very large (~10 million) dimensional latent parameter space can be explored with Hamiltonian Monte Carlo techniques.  As an alternative, we also explore likelihood-free (or simulation-based) inference for cases where we have a good data simulator.  Using extreme (and in some sense lossless) data compression methods, similar precision to HBMs can be achieved in at least some use cases. I will also touch on new related work in cosmology involving graph neural networks.

Attendee Instructions:
FI employees are welcome to attend in person. Please email ccaadmin@flatironinstitute.org for the Zoom link if you wish to attend remotely.
Visitors (w/out an FI badge) please email ccaadmin@flatironinstitute.org 24hrs in advance to be registered to the building or to obtain Zoom information.

Additional Information:
COVID Policy: By making entry to our buildings all staff, vendors and guests will implicitly attest to being symptom/COVID free. Vaccination status will no longer be validated as a condition of entry. However, all staff and affiliates are strongly encouraged to remain up to date with their vaccination boosters, according to their individual eligibility.

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