Tim Sullivan

Junior Professor in Applied Mathematics with Specialism in Risk and Uncertainty Quantification


UQ Summer School at WIAS

From 12–16 September 2016, there will be a summer school on uncertainty quantification jointly organized by the GAMM Activity Group on Uncertainty Quantification, the International Research and Training Group Munich-Graz and WIAS. The invited lecturers are:

  • Howard Elman (U Maryland): Reduced Basis Methods for Random PDEs
  • Lars Grasedyck (RWTH Aachen): Sparse Tensor Approximations
  • Claudia Schillings (U Warwick): Ensemble Kalman Filters and MCMC for Bayesian Inversion
  • Raul Tempone (KAUST): Multilevel and Multiindex Monte-Carlo Methods
  • Bruno Sudret (ETH Zürich): Engineering Risk Analysis with UQ-LAB

Contact the organisers at uq-school16@wias-berlin.de for further information.

Posted 18 March 2016

Ingmar Schuster

UQ Talks: Ingmar Schuster

Ingmar Schuster (Université Paris-Dauphine) “Gradient Importance Sampling”

Time and Place. Friday 11 March 2016, 11:15–12:45, Room 126 of Arnimallee 6 (Pi-Gebäude), 14195 Berlin

Abstract. Adaptive Monte Carlo schemes developed over the last years usually seek to ensure ergodicity of the sampling process in line with MCMC tradition. This poses constraints on what is possible in terms of adaptation. In the general case ergodicity can only be guaranteed if adaptation is diminished at a certain rate. Importance Sampling approaches offer a way to circumvent this limitation and design sampling algorithms that keep adapting. Here I present an adaptive variant of the discretized Langevin algorithm for estimating integrals with respect to some target density that uses an Importance Sampling instead of the usual Metropolis–Hastings correction.

Posted 8 March 2016

Introduction to Uncertainty Quantification

Introduction to Uncertainty Quantification Now Available as e-Book and Hardcover

A 350-page introduction to the key mathematical ideas underlying uncertainty quantification, designed as a course text or self-study for finalist undergraduates, master's students, or beginning doctoral students.

T. J. Sullivan. Introduction to Uncertainty Quantification, volume 63 of Texts in Applied Mathematics. Springer, 2015. ISBN 978-3-319-23394-9 (hardcover) 978-3-319-23395-6 (e-book) doi:10.1007/978-3-319-23395-6

Posted 22 December 2015

Free University of Berlin

Opening for Postdoctoral Researcher

There is an opening in my research group for a postdoctoral researcher in Uncertainty Quantification. Strong candidates with backgrounds in mathematics, statistics, or computational science are encouraged to apply. For details see:

Review of applications will begin on 11 January 2016 and will continue until the post is filled.

Posted 21 December 2015

On the Brittleness of Bayesian Inference

Bayesian Brittleness in SIAM Review

The 2015Q4 issue of SIAM Review will carry an article by Houman Owhadi, Clint Scovel, and myself on the brittle dependency of Bayesian posteriors as a function of the prior. This is an abbreviated presentation of results given in full earlier this year in Elec. J. Stat. The PDF is available for free under the terms of the Creative Commons 4.0 licence.

H. Owhadi, C. Scovel & T. J. Sullivan. “On the Brittleness of Bayesian Inference” SIAM Review 57(4):566–582, 2015. doi:10.1137/130938633

Posted 17 November 2015