On the convergence of generalized polynomial chaos expansions OG Ernst, A Mugler, HJ Starkloff, E Ullmann ESAIM: Mathematical Modelling and Numerical Analysis 46 (2), 317-339, 2012 | 485 | 2012 |

Further analysis of multilevel Monte Carlo methods for elliptic PDEs with random coefficients AL Teckentrup, R Scheichl, MB Giles, E Ullmann Numerische Mathematik 125 (3), 569-600, 2013 | 229 | 2013 |

Stochastic Galerkin matrices OG Ernst, E Ullmann SIAM Journal on Matrix Analysis and Applications 31 (4), 1848-1872, 2010 | 128 | 2010 |

Computational aspects of the stochastic finite element method M Eiermann, OG Ernst, E Ullmann Computing and visualization in science 10 (1), 3-15, 2007 | 124 | 2007 |

Multilevel quasi-Monte Carlo methods for lognormal diffusion problems F Kuo, R Scheichl, C Schwab, I Sloan, E Ullmann Mathematics of Computation 86 (308), 2827-2860, 2017 | 93 | 2017 |

A Kronecker product preconditioner for stochastic Galerkin finite element discretizations E Ullmann SIAM Journal on Scientific Computing 32, 923-946, 2010 | 93 | 2010 |

Efficient solvers for a linear stochastic Galerkin mixed formulation of diffusion problems with random data OG Ernst, CE Powell, S David J, E Ullmann SIAM Journal on Scientific Computing 31 (2), 1424-1447, 2009 | 93 | 2009 |

Efficient iterative solvers for stochastic Galerkin discretizations of log-transformed random diffusion problems E Ullmann, HC Elman, OG Ernst SIAM Journal on Scientific Computing 34 (2), A659 - A682, 2012 | 91 | 2012 |

Multilevel estimation of rare events E Ullmann, I Papaioannou SIAM/ASA J. Uncertainty Quantification 3 (1), 922-953, 2015 | 51 | 2015 |

Multilevel Sequential Monte Carlo for Bayesian Inverse Problems J Latz, I Papaioannou, E Ullmann Journal of Computational Physics 368, 154-178, 2018 | 49 | 2018 |

Solution strategies for stochastic finite element discretizations E Ullmann | 45 | 2008 |

Multilevel Monte Carlo analysis for optimal control of elliptic PDEs with random coefficients A Ahmad Ali, E Ullmann, M Hinze SIAM/ASA J. Uncertainty Quantification 5 (1), 466 - 492, 2017 | 44 | 2017 |

Preconditioning Stochastic Galerkin Saddle Point Problems CE Powell, E Ullmann Preprint 31, 2009 | 43 | 2009 |

Preconditioning stochastic Galerkin saddle point systems CE Powell, E Ullmann SIAM Journal on Matrix Analysis and Applications 31 (5), 2813-2840, 2010 | 40 | 2010 |

Analysis of Boundary Effects on PDE-Based Sampling of Whittle--Matérn Random Fields U Khristenko, L Scarabosio, P Swierczynski, E Ullmann, B Wohlmuth SIAM/ASA Journal on Uncertainty Quantification 7 (3), 948-974, 2019 | 32 | 2019 |

Mixed Finite Element analysis of lognormal diffusion and multilevel Monte Carlo methods IG Graham, R Scheichl, E Ullmann Stochastic Partial Differential Equations: Analysis and Computations, 2015 | 28 | 2015 |

Fast sampling of parameterised Gaussian random fields J Latz, M Eisenberger, E Ullmann Computer Methods in Applied Mechanics and Engineering 348, 978-1012, 2019 | 20 | 2019 |

Multilevel sequential importance sampling for rare event estimation F Wagner, J Latz, I Papaioannou, E Ullmann SIAM Journal on Scientific Computing 42 (4), A2062–A2087, 2020 | 19 | 2020 |

Bayesian Parameter Identification in Cahn-Hilliard Models for Biological Growth C Kahle, KF Lam, J Latz, E Ullmann SIAM/ASA Journal on Uncertainty Quantification 7 (2), 526-552, 2019 | 18 | 2019 |

On multilevel best linear unbiased estimators D Schaden, E Ullmann SIAM/ASA J. Uncertainty Quantification 8 (2), 601 - 635, 2020 | 14 | 2020 |