Dr. Michael Quellmalz

Publications

Preprint

• Michael Quellmalz, Mia Kvåle Løvmo, Simon Moser, Franziska Strasser, Monika Ritsch-Marte:
  Application and Evaluation of the Common Circles Method
  ArXiv preprint 2602.17353. (pdf)

• Antonin Clerk, Michael Quellmalz, Moritz Piening, Philipp Flotho, Gregor Kornhardt, Gabriele Steidl:
  HOT-POT: Optimal Transport for Sparse Stereo Matching
  ArXiv preprint 2601.12423. (pdf)

• Nicolaj Rux, Michael Quellmalz, Gabriele Steidl:
  Smoothed Distance Kernels for MMDs and Applications in Wasserstein Gradient Flows
  ArXiv preprint 2504.07820. (pdf)

Articles

• Johannes Hertrich, Tim Jahn, Michael Quellmalz:
  Fast Summation of Radial Kernels via QMC Slicing
  International Conference on Learning Representations (ICLR 2025). https://openreview.net/forum?id=iNmVX9lx9l
  ArXiv preprint 2410.01316. (pdf)

• Clemens Kirisits, Michael Quellmalz, Eric Setterqvist:
  Generalized Fourier Diffraction Theorem and Filtered Backpropagation for Tomographic Reconstruction
  SIAM Journal on Imaging Sciences Vol. 18, Iss. 1, 2025. doi:10.1137/24M167370X
  ArXiv preprint 2407.01793. (pdf)

• Nicolaj Rux, Michael Quellmalz, Gabriele Steidl:
  Slicing of Radial Functions: a Dimension Walk in the Fourier Space
  Sampling Theory, Signal Processing, and Data Analysis 23, Article number: 6 (40 pages), 2025. doi:10.1007/s43670-025-00100-9 (Open Access)
  ArXiv preprint 2408.11612. (pdf)

• Oleh Melnyk, Michael Quellmalz, Gabriele Steidl, Noah Jaitner, Jakob Jordan, Ingolf Sack:
  Time-Harmonic Optical Flow with Applications in Elastography
  Inverse Problems 40(12), 125026 (29 pages), December 2024. doi:10.1088/1361-6420/ad9776 (Open Access)
  ArXiv preprint 2405.15507. (pdf)

• Michael Quellmalz, Léo Buecher, Gabriele Steidl:
  Parallelly Sliced Optimal Transport on Spheres and on the Rotation Group
  Journal of Mathematical Imaging and Vision 66(6), pages 951-976, 2024. doi:10.1007/s10851-024-01206-w (Open Access) (pdf)

• Michael Quellmalz, Peter Elbau, Otmar Scherzer, Gabriele Steidl:
  Motion Detection in Diffraction Tomography by Common Circle Methods
  Mathematics of Computation 93(346), pages 747–784, March 2024. doi:10.1090/mcom/3869
  ArXiv preprint 2209.08086. (pdf)

• Michael Quellmalz, Robert Beinert, Gabriele Steidl:
  Sliced Optimal Transport on the Sphere
  Inverse Problems 39(10), 105005 (34 pages), 2023. doi:10.1088/1361-6420/acf156
  ArXiv preprint 2304.09092. (pdf)

• Sophie Mildenberger, Michael Quellmalz:
  A double Fourier sphere method for d-dimensional manifolds
  Sampling Theory, Signal Processing, and Data Analysis 21, Article number: 23 (40 pages), 2023. doi:10.1007/s43670-023-00064-8 (Open Access) (pdf)

• Michael Quellmalz, Lukas Weissinger, Simon Hubmer, Paul Erchinger:
  A Frame Decomposition of the Funk-Radon Transform
  L. Calatroni, M. Donatelli, S. Morigi, M. Prato, M. Santacesaria (Eds.): Scale Space and Variational Methods in Computer Vision. SSVM 2023, pages 42-54. Lecture Notes in Computer Science, vol 14009. Springer, Cham, 2023. doi:10.1007/978-3-031-31975-4_4
  ArXiv preprint 2303.05179. (pdf)

• Florian Faucher, Clemens Kirisits, Michael Quellmalz, Otmar Scherzer, Eric Setterqvist:
  Diffraction Tomography, Fourier Reconstruction, and Full Waveform Inversion
  In: Ke Chen, Carola B. Schönlieb, Xue-Cheng Tai, Laurent Younces (Eds.) Handbook of Mathematical Models and Algorithms in Computer Vision and Imaging, pages 273-312. Springer, Cham, 2023. doi:10.1007/978-3-030-98661-2_115
  ArXiv preprint 2110.07921. (pdf)

• Robert Beinert, Michael Quellmalz:
  Total Variation-Based Reconstruction and Phase Retrieval for Diffraction Tomography with an Arbitrarily Moving Object
  Proceedings in Applied Mathematics & Mechanics, 22(1), 6 pages, 2023. doi:10.1002/pamm.202200135 (Open Access). (pdf)

• Robert Beinert, Michael Quellmalz:
  Total Variation-Based Reconstruction and Phase Retrieval for Diffraction Tomography
  SIAM Journal on Imaging Sciences 15(3), p. 1373-1399 (2022). doi:10.1137/22M1474382
  ArXiv preprint 2201.11579. (pdf)

• Fatima Antarou Ba, Michael Quellmalz:
  Accelerating the Sinkhorn Algorithm for Sparse Multi-Marginal Optimal Transport via Fast Fourier Transforms
  Algorithms 15(9) (2022), p. 311. doi:10.3390/a15090311 (Open Access). (pdf)

• Sophie Mildenberger, Michael Quellmalz:
  Approximation Properties of the Double Fourier Sphere Method
  Journal of Fourier Analysis and Applications 28(2), Article number 31 (2022). doi:10.1007/s00041-022-09928-4 (Open Access) (pdf)

• Stephan Dahlke, Filippo De Mari, Ernesto De Vito, Markus Hansen, Marzieh Hasannasab, Michael Quellmalz, Gabriele Steidl, Gerd Teschke:
  Continuous Wavelet Frames on the Sphere: The Group-Theoretic Approach Revisited
  Applied and Computational Harmonic Analysis 56 (2022), p. 123-149. doi:10.1016/j.acha.2021.08.003
  ArXiv preprint 2012.13460. (pdf)

• Clemens Kirisits, Michael Quellmalz, Monika Ritsch-Marte, Otmar Scherzer, Eric Setterqvist, Gabriele Steidl:
  Fourier Reconstruction for Diffraction Tomography of an Object Rotated Into Arbitrary Orientations
  Inverse Problems 37 (2021), 115002. doi:10.1088/1361-6420/ac2749 (Open Access). (pdf)

• Michael Quellmalz:
  The Funk-Radon transform for hyperplane sections through a common point
  Analysis and Mathematical Physics 10(38), 2020. doi:10.1007/s13324-020-00383-2 (Open Access). (pdf)

• Michael Quellmalz, Ralf Hielscher, Alfred K. Louis:
  The Cone-Beam Transform and Spherical Convolution Operators
  Inverse Problems 34 (2018) 105006. doi:10.1088/1361-6420/aad679
  ArXiv postprint 1803.10515. (pdf)

• Ralf Hielscher, Daniel Potts, Michael Quellmalz:
  An SVD in Spherical Surface Wave Tomography
  In: Bernd Hofmann, Antonio Leitao and Jorge P. Zubelli (Eds.). New Trends in Parameter Identification for Mathematical Models, p. 121-144, Birkhäuser Basel, 2018. doi:10.1007/978-3-319-70824-9_7
  ArXiv postprint 1706.05284. (pdf)

• Michael Quellmalz:
  A Generalization of the Funk–Radon Transform
  Inverse Problems 33 (2017) 035016. doi:10.1088/1361-6420/33/3/035016 (pdf)

• Ralf Hielscher, Michael Quellmalz:
  Reconstructing a Function on the Sphere from Its Means Along Vertical Slices
  Inverse Problems and Imaging 10(3), 2016. doi:10.3934/ipi.2016018 (pdf)

• Ralf Hielscher, Michael Quellmalz:
  Optimal Mollifiers for Spherical Deconvolution
  Inverse Problems 31 (2015) 085001. doi:10.1088/0266-5611/31/8/085001 (pdf)

Theses

• Michael Quellmalz:
  Inversion of the Circular Average Transform on the Sphere
  Diploma thesis, TU Chemnitz, 2014. (pdf)

Talks

Conferences and Workshops

• Workshop and Summer School on Applied Analysis, Chemnitz, 22 – 26 September 2025
  Fast and Accurate Approximation of High-Dimensional Radial Kernels via Slicing (pdf)

• SFB Conference Tomography Across the Scales, Strobl, Österreich, 16–21 June 2025
  

• ICLR, Singapore, 24–28 April 2025
  Fast Summation of Radial Kernels via QMC Slicing (pdf)

• Workshop on Approximation Theory and Fast Algorithms, Hasenwinkel, 7 – 11 April 2025
  Fast and Accurate Approximation of High-Dimensional Radial Kernels via Slicing (pdf)

• Kolloquium des Instituts für Mathematik, Universität Osnabrück, 22 January 2025
  Fast and Accurate Approximation of High-Dimensional Radial Kernels via Slicing

• GIP 2024 Annual Meeting, Siegen, 25 – 27 September 2024
  Generalized Fourier Diffraction Theorem and Filtered Backpropagation for Tomographic Reconstruction (pdf)

• Workshop and Summer School on Applied Analysis, Chemnitz, 16 – 20 September 2024
  Motion detection in diffraction tomography (pdf)

• Inverse Problems: Modeling & Simulation, Mellieha, Malta, 26 May – 1 June 2024
  Motion detection in diffraction tomography (pdf)

• Optimal Transport: From Theory to Applications, WIAS Berlin, 11 – 15 March 2024
  Sliced Optimal Transport on the Sphere (Poster) (pdf)

• Chemnitz Symposium on Inverse Problems 2023, Würzburg, 8–10 November 2023
  Sliced Optimal Transport on the Sphere (pdf)

• DMV Meeting, TU Ilmenau, 25–28 September 2023
  Motion Detection in Diffraction Tomography (pdf)

• AIP Applied Inverse Problems Conference, Göttingen, 4–8 September 2023
  Motion Detection in Diffraction Tomography (pdf)

• SSVM2023: 9th International Conference on Scale Space and Variational Methods in Computer Vision, Santa Margherita di Pula, Sardinia, 21–25 May 2023
  A Frame Decomposition of the Funk-Radon Transform (pdf)

• RICAM Special Semester Tomography Across the Scales, Workshop Inverse Problems on Small Scales, RICAM, Linz, 17–21 October 2022
  Motion Detection in Diffraction Tomography (pdf)

• Inverse Problems: From experimental data to models and back (Chemnitz Symposium on Inverse Problems 2022), Potsdam, 19 – 21 September 2022
  Optical Diffraction Tomography with an Object Rotated into Arbitrary Orientations (pdf)

• 8th International Conference on Computational Harmonic Analysis (ICCHA2022), Ingolstadt, 12 – 16 September 2022
  Fourier Reconstruction in Diffraction Tomography of an Irregularly Moving Object (pdf)

• Inverse Problems: Modeling & Simulation, Mellieha, Malta, 22 – 28 May 2022
  Fourier Reconstruction in Diffraction Tomography of an Irregularly Moving Object (pdf)

• SIAM Conference on Imaging Science (SIAM-IS 2022), TU Berlin (online), 21 – 25 March 2022
  Fourier Reconstruction in Diffraction Tomography of an Irregularly Moving Object (pdf)

• Conference on Mathematics of Wave Phenomena 2022, KIT, Karlsruhe (online), February 14 – 18, 2022
  Approximation properties of the double Fourier sphere method (pdf)

• International Conference of Young Mathematicians, Institute of Mathematics of NAS of Ukraine (online), 3 – 5 June 2021
  The Fourier diffraction theorem in optical tomography

• MATH+ Spotlight, TU Berlin (online), 2 June 2021
  EF3-6: Deformation Based Regularization of Inverse Problems on Manifolds (pdf)

• Chemnitz Symposium on Inverse Problems, Frankfurt, 30 September – 2 October 2019
  Reconstructing Functions on the Sphere from Circular Means (pdf)

• 2nd IMA Conference On Inverse Problems From Theory To Application, London, 4 – 6 September 2019
  The Funk-Radon transform and spherical tomography (pdf)

• Siegmundsburg Seminar on Analysis & Theoretical Numerics, Siegmundsburg, 26 – 28 August 2019
  Sobolev estimates for spherical means and the Funk-Radon transform (pdf)

• Applied Inverse Problems Conference AIP 2019, Grenoble, 8 – 12 July 2019
  The Funk-Radon transform and spherical tomography (pdf)

• Approximation Theory 16, Nashville, 19 – 22 May 2019
  The cone-beam transform and spherical convolutions (pdf)

• Workshop on Mathematical Signal and Image Analysis, Raitenhaslach, 1 – 3 April 2019
  The cone-beam transform and spherical convolution operators (pdf)

• Chemnitz Symposium on Inverse Problems, TU Chemnitz, 27 und 28 September 2018
  The cone-beam transform and spherical convolution operators (pdf)

• Mecklenburg Workshop Approximation Methods and Fast Algorithms, Hasenwinkel, Mecklenburg-Vorpommern, Germany, 10 – 14 September 2018
  The cone-beam transform and spherical convolution operators (pdf)

• SIAM Conference on Imaging Science (SIAM-IS 2018), Bologna, Italy, 5 – 8 June 2018
  The cone-beam transform and spherical convolution operators (pdf)

• Inverse Problems: Modeling & Simulation, Mellieha, Malta, 21 – 26 May 2018
  An SVD in spherical surface wave tomography (pdf)

• Modeling, analysis, and approximation theory toward applications in tomography and inverse problems, TU Braunschweig, February 3 – 7, 2018
  The Funk-Radon transform and its generalizations (pdf)

• New Trends in Parameter Identification for Mathematical Models, IMPA, Rio de Janeiro, Brazil, October 30 – November 3, 2017
  An SVD in spherical surface wave tomography (pdf)

• Geomathematics Meets Medical Imaging, Speyer, 5 – 8 September 2017
  An SVD in spherical surface wave tomography (pdf)

• 100 Years of the Radon Transform, RICAM, Linz, Austria, 27 – 31 March 2017
  A generalization of the Funk-Radon transform (pdf)

• 27. Rhein-Ruhr-Workshop, Bestwig, 27 – 28 January 2017
  Eine Verallgemeinerung der Funk-Radon-Transformation (pdf)

• Chemnitz Symposium on Inverse Problems, TU Chemnitz, 22 – 23 September 2016
  A generalization of the Funk-Radon transform (pdf)

• Mecklenburg Workshop Approximation Methods and Data Analysis, Hasenwinkel, Mecklenburg-Vorpommern, Germany, 5 – 9 September 2016
  A generalization of the Funk-Radon transform (pdf)

• Mathematical Imaging and Emerging Modalities, Osnabrück, Germany, 27 – 30 June 2016
  A generalization of the Funk-Radon transform (pdf)

• Inverse Problems: Modeling & Simulation, Fethiye, Turkey, 23 – 28 May 2016
  A generalization of the spherical Radon transform to circles passing through a fixed point (pdf)

• 26. Rhein-Ruhr-Workshop, Bestwig, 29 – 30 January 2016
  Eine Verallgemeinerung der Funk-Radon-Transformation für Kreise durch einen festen Punkt (pdf)

• Recent Developments in Inverse Problems, Berlin, Germany, 17 – 18 September 2015
  Optimal mollifiers for reconstructing spherical images from circular means (pdf)

• Mecklenburg Workshop Approximation Methods and Function Spaces, Hasenwinkel, Mecklenburg-Vorpommern, Germany, 16 – 20 März 2015
  Optimal Mollifiers for Spherical Deconvolution (pdf)

• 25. Rhein-Ruhr-Workshop, Bestwig, 30 – 31 January 2015
  Optimal Mollifiers for Spherical Deconvolution (pdf)

• Helmholtz-Workshop: Mathematics for imaging, Bad Harzburg, Lower Saxony, Germany, 2 – 4 April 2014
  Optimal kernels for the inversion of the spherical Radon and cosine transform (pdf)

Poster

• Computational and Analytical Aspects of Image Reconstruction, ICERM, Brown University, Providence, Rhode Island, 13 – 17 July 2015
  Reconstruction of Functions on the Sphere from Spherical Means (pdf)

Seminar talks

• 18th Internal Meeting of the SFB Tomography Across the Scales, Obergurgl, Österreich, 2–5 December 2025
  

• 8th Member Meeting of the SFB Tomography Across the Scales, Bad Ischl, Österreich, 9–12 September 2025
  

• 17th Internal Meeting of the SFB Tomography Across the Scales, Obergurgl, Österreich, 3–6 December 2024
  

• Seminar Angewandte Analysis, TU Freiberg, 13 November 2024
  

• 7th Member Meeting of the SFB Tomography Across the Scales, Bad Goisern, Österreich, 9–12 September 2024
  Time-Harmonic Optical Flow with Applications in Elastography

• 16th Internal Meeting of the SFB Tomography Across the Scales, Strobl, Österreich, 1 – 5 July 2024
  Update on diffraction tomography

• 15th Internal Meeting of the SFB Tomography Across the Scales, Obergurgl, Österreich, 27–30 November 2023
  Universal filtered backpropagation formula for diffraction tomography with various imaging setups

• Sixth Member Meeting of the SFB Tomography Across the Scales, Wildalpen, Österreich, 12–15 September 2023
  Sliced Optimal Transport on the Sphere

• Fourteenth Internal Meeting of the SFB Tomography Across the Scales, Wildalpen, Österreich, 3–5 July 2023
  Motion Detection from 2D Projections of Moving Particles

• Thirteenth Internal Meeting of the SFB Tomography Across the Scales, Windischgarsten, Österreich, 12–15 February 2023
  Update on Diffraction Tomography

• Twelfth Internal Meeting of the SFB Tomography Across the Scales, Obergurgl, Österreich, 4–7 December 2022
  Motion Detection in Diffraction Tomography

• Fifth Member Workshop of the SFB Tomography Across the Scales, Gmunden, Österreich, 26–29 September 2022
  Approximation Properties of the Double Fourier Sphere Method

• Eleventh Internal Meeting of the SFB Tomography Across the Scales, Windischgarsten, Österreich, 19–22 June 2022
  Motion Detection in Diffraction Tomography by Common Circle Methods

• Research Seminar Analysis, TU Chemnitz (online), 26 March 2021
  Fourier reconstruction in diffraction tomography with an arbitrarily rotated object

• Sixth Internal Meeting of the SFB Tomography Across the Scales, Wien (online), 30 November 2020
  Reconstruction Formulae in Diffraction Tomography based on NFFTs and Backpropagation

• Fifth Internal Meeting of the SFB Tomography Across the Scales, Wien (online), 1 September 2020
  

• Öffentliche Prüfung im Promotionsverfahren, TU Chemnitz, 26 November 2019
  Reconstructing Functions on the Sphere from Circular Means

• Forschungsseminar Analysis, Faculty of Mathematics, TU Chemnitz, 23 January 2018
  The Funk-Radon transform and its generalizations

• PhD Seminar, TU Chemnitz, 12 December 2016
  An introduction to reproducing kernel Hilbert spaces

• PhD Seminar, TU Chemnitz, 19 May 2016
  A generalization of the Funk-Radon transform

• PhD Seminar, TU Chemnitz, 20 January 2015
  The Funk–Radon transform

• Seminar Applied Analysis, TU Chemnitz, 10 June 2013
  Schnelle Legendre–Transformation

Further Talks

• Infoveranstaltung Digitale Prüfungen, TU Berlin (online), 7 June 2021
  How to STACK (Fragetyp in ISIS/Moodle für Formelaufgaben) (pdf)

• TUCdigital Tage der digitalen Hochschulbildung, TU Chemnitz, 14 – 15 January 2020
  Lit.Shortcut, Digitale Prüfungen in OPAL. Das Prüfungssystem ONYX in der praktischen Anwendung

• 13. Netzwerktreffen Mathematik/Physik + E-Learning, Hochschule für Technik und Wirtschaft Dresden, 11 September 2019
  Adaptives Feedback und individualisierte Aufgabengestaltung – Technologie und Praxis

• 12. Netzwerktreffen Mathematik/Physik + E-Learning, Technische Universität Bergakademie Freiberg, 12 March 2019
  Die stetige Weiterentwicklung im Aufgabenpool Mathematik (pdf)

• LiT.Shortcut, Technische Universität Bergakademie Freiberg, 7 November 2018
  Onyx in der Hochschullehre – mit Onlinetests mathematische Aufgaben in die Lehre integrieren (pdf)

• 15. OPAL-Supporter-Treffen, TU Chemnitz, 14 June 2018
  Formatives E-Assessment in Mathematik-Lehrveranstaltungen (pdf)

Further Workshops or Meetings

• Mathematics and Industry, Physikalisch-Technische Bundesanstalt, Berlin, 3 November 2023
  

• Mecklenburg Workshop: Data Analysis und Approximation, Hasenwinkel, 7 July 2023
  

• MIA 2023 Mathematics and Image Analysis, WIAS Berlin, 1–3 February 2023
  

• Tenth Internal Meeting of the SFB Tomography Across the Scales, Obergurgl (hybrid), Österreich, 17–20 March 2022
  

• Kick-off Workshop Thematic Einstein Semester on Mathematics of Imaging in Real-World Challenges, Physikalisch-Technische Bundesanstalt, Berlin, 6 – 8 October 2021
  

• Siegmundsburg Seminar on Analysis & Theoretical Numerics, Siegmundsburg, 31 August – 2 September 2021
  

• Tomographic Reconstructions and their Startling Applications, Erwin Schrödinger Institute, Wien (online), 15 – 25 March 2021
  

• Chemnitz Symposium on Inverse Problems, TU Chemnitz (online), 14 – 17 September 2020
  

• Siegmundsburg Seminar on Analysis & Theoretical Numerics, Siegmundsburg, 27 – 29 July 2020
  

• Computational and Mathematical Methods in Data Science, Berlin, 24 – 25 October 2019
  

• 29. Rhein-Ruhr-Workshop, Bestwig, 1 – 2 February 2019
  

• 28. Rhein-Ruhr-Workshop, Bestwig, 2 – 3 February 2018