Prof. Dr. Simon Weißmann

Prof. Dr. Simon Weißmann

Assistant Professor of applied stochastics
University of Mannheim
Business Informatics and Mathematics
B 6, 26
Mathematical Institute – Room 3.05
68159 Mannheim

Short CV

Research Interests

  • (Bayesian) Inverse Problems
  • (Stochastic) Optimization
  • (Ensemble) Kalman Filtering
  • Monte Carlo methods
  • Rare event simulation
  • Application in Machine Learning 

Teaching

Lectures

University of Mannheim
HWS 2024Optimization in Machine Learning (BSc/MSc)
FSS 2024Inverse Problems (MSc)

HWS 2023

Mathematical Finance (BSc)
HWS 2023

Reinforcement Learning 2 (MSc) 

joint with L. Döring and M. Staudigl

FSS 2023

Optimization in Machine Learning (BSc/MSc)

Lecture Notes:

Seminars

University of Mannheim
HWS 2024Advanced Seminar on Mathematical methods in Artificial Intelligence (BSc/MSc)
FSS 2024Mathematical Optimization (BSc/MSc)
HWS 2023

Advanced Seminar on Mathematical methods in Artificial Intelligence (BSc/MSc)

Heidelberg University

WiSe 2021

Simulation of Stochastic Systems (BSc/MSc)

Publications

Preprints and submitted manuscripts

2025

Clustered KL-barycenter design for policy evaluation

S. Weissmann, T. Freihaut, C. Vernade, G. Ramponi and L. Döring

Submitted

2024

Derivative-free stochastic optimization for inverse problems

M. Staudigl, S. Weissmann and T. van Leeuwen

Preprint: arxiv:2411.18100


Structure Matters: Dynamic Policy Gradient

S. Klein, X. Zhang, T. Başar, S. Weissmann and L. Döring

Preprint: arxiv:2411.04913


Polyak's heavy ball method achieves accelerated local rate of convergence under Polyak-Lojasiewicz inequality

S. Kassing and S. Weissmann

Preprint: arxiv:2410.16849


On the mean field limit of consensus based methods

M. Koß, S. Weissmann and J. Zech

Preprint: arXiv:2409.03518


Almost sure convergence rates of stochastic gradient methods under gradient domination

S. Weissmann, S. Klein, W. Azizian and L. Döring

Preprint: arXiv:2405.13592


On the mean-field limit for Stein variational gradient descent: stability and multilevel approximation

S. Weissmann and J. Zech

Preprint: arXiv:2402.01320


Articles in journals and refereed proceedings volumes

2025

Metropolis-adjusted interacting particle sampling

B. Sprungk, S. Weissmann and J. Zech

Statistics and Computing (accepted)

Preprint: arXiv:2312.13889

2024

The ensemble Kalman filter for dynamic inverse problems

S. Weissmann, N. Chada and X. Tong

Information and Inference: A Journal of the IMA, Volume 13, Issue 4, doi: 10.1093/imaiai/iaae030


Adaptive multilevel subset simulation with selective refinement

D. Elfverson, R. Scheichl, S. Weissmann and F. A. DiazDelaO

SIAM/ASA Journal on Uncertainty Quantification, Volume 12, Issue 3, doi: 10.1137/22M151524


On the ensemble Kalman inversion under inequality constraints

M. Hanu and S. Weissmann

Inverse Problems, Volume 40, Number 9, doi: 10.1088/1361-6420/ad6a33


One-shot learning of surrogates in PDE-constrained Optimization under Uncertainty

P. Guth, C. Schillings and S. Weissmann

SIAM/ASA Journal on Uncertainty Quantification, Volume 12, Issue 2, doi: 10.1137/23M155317


Beyond Stationarity: Convergence Analysis of Stochastic Softmax Policy Gradient Methods 

S. Klein, S. Weissmann and L. Döring

In: The Twelfth International Conference on Learning Representations (ICLR) 2024

 Preprint: arXiv:2310.02671

2022

Continuous time limit of the stochastic ensemble Kalman inversion: Strong convergence analysis

D. Blömker, C. Schillings, P. Wacker and S. Weissmann

SIAM Journal on Numerical Analysis, Volume 60, Issue 6, doi: 10.1137/21M1437561


Gradient flow structure and convergence analysis of the ensemble Kalman inversion for nonlinear forward models

S. Weissmann

Inverse Problems, Volume 38, Number 10, doi: 10.1088/1361-6420/ac8bed


Multilevel optimization for inverse problems

S. Weissmann, A. Wilson and J. Zech

Proceedings of Thirty Fifth Conference on Learning Theory (COLT 2022), PMLR 178:5489-5524


Adaptive Tikhonov regularization for stochastic ensemble Kalman inversion

S. Weissmann, N. Chada, C. Schillings and X. Tong

Inverse Problems, Volume 38, Number 4, doi: 10.1088/1361-6420/ac5729


Consistency analysis of bilevel data-driven regularization in inverse problems

N. Chada, C. Schillings, X. Tong and S. Weissmann

Communications in Mathematical Sciences, Volume 20, Number 1, doi: 10.4310/CMS.2022.v20.n1.a4

2021

Ensemble Kalman filter for neural network based one-shot inversion

P. Guth, C. Schillings and S. Weissmann

In: Optimization and Control for Partial Differential Equations, De Gruyter, doi: 10.1515/9783110695984-014


Fokker–Planck particle systems for Bayesian inference: computational approaches

S. Reich and S. Weissmann

SIAM/ASA Journal on Uncertainty Quantification, Volume 9, Issue 2, doi: 10.1137/19M1303162


Well posedness and convergence analysis of the ensemble Kalman Inversion

D. Blömker, C. Schillings, P. Wacker and S. Weissmann

Inverse Problems, Volume 35, Number 8, doi: 10.1088/1361-6420/ab149c


On the incorporation of box-constraints for ensemble Kalman Inversion

N. Chada, C. Schillings and S. Weissmann

Foundations of Data Science, Volume 1, Issue 4, doi: 10.3934/fods.2019018


    Theses 

    2020

    Particle based sampling and optimization methods for inverse problems

    S. Weissmann

    Dissertation, University of Mannheim, link

    2017

    Perpetual Integrals for stochastic processes

    S. Weissmann

    Master Thesis, University of Mannheim

    2015

    Renewal processes – Alternation, excesslife and agedistribution

    S. Weissmann

    Bachelor Thesis, University of Mannheim