Current projects

Discovering structure in complex data: Statistics meets Optimization and Inverse Problems (2015-2024) DFG Research Training Group 2088 (RTG 2088)

Completed projects

Approximation properties of interpolation and quasi-interpolation operators (2018-2021) DFG project KO 5804/1

Teaching

	Research seminar: Numerical Analysis (English) (SS 2024) Tuesday 12.30 - 14.00 (2 SWS)
	Lecture: An Introduction to Compressed Sensing (English) (WS 2023/2024) Monday and Thursday 10.15 - 11.55 (Lecture and Exercises 4 SWS / 6 ECTS)
	Research seminar: Numerical Analysis (English) (WS 2023/2024) Tuesday 12.30 - 14.00 (2 SWS)
	Research seminar: Numerical Analysis (English) (SS 2023) Tuesday 12.30 - 14.00 (2 SWS)
	Research seminar: Numerical Analysis (English) (WS 2022/2023) Thursday 12.30 - 14.00 (2 SWS)
	Research seminar: Numerical Analysis (English) (SS 2022) Thursday 12.30 - 14.00 (2 SWS)
	Lecture: Fourier Analysis and Approximation (English) (SS 2022) Tuesday and Friday 8.15 - 09.55 (Lecture+ Exercises: 4 SWS / 6 ECTS)
	Research seminar: Numerical Analysis (English) (WS 2021/2022) Thursday 12.30 - 14.00, online (2 SWS)

Workshops

	8th RTG Workshop 2023 October 4-6, 2023 in Mariaspring, Germany
	From Modeling and Analysis to Approximation and Fast Algorithms (Talk) September 02-06 2023 in Hasenwinkel
	Data Analysis and Approximation July 07 2023 in Hasenwinkel
	International Conference Constructive Theory of Functions - 2023 (Talk) June 11 - 15, 2023 in Lozenets, Bulgaria
	From Modeling and Analysis to Approximation and Fast Algorithms (Plenary Talk) December 2-6, 2022 in Hasenwinkel, Germany
	International Conference on Function Spaces and Applications (FSA 2022) (Plenary Talk) October 1-7, 2022 in Apolda, Germany
	Multivariate Approximation and Interpolation with Applications (MAIA) (Invited Talk) September 26-30, 2022 in Fuldatal, Germany
	7th RTG Workshop 2022 August 29-31, 2022 in Goslar, Germany
	31. Rhein-Ruhr-Workshop (Talk) February 11 - February 12, 2022 in Bestwig

Publications

	Sharp Lp-error estimates for sampling operators Yurii Kolomoitsev, Tetiana Lomako J. Approx. Theory, Available online 26 June 2023, 105941, 2023 (preprint available at arXiv)
	Spline Representation and Redundancies of One-Dimensional ReLU Neural Network Models Gerlind Plonka, Yannick Nicola Riebe, Yurii Kolomoitsev Analysis and Applications 21(01), 127-163, 2023 (preprint available at arXiv)
	On generalized K-functionals in Lp for 0 < p < 1 Yurii Kolomoitsev, Tetiana Lomako Fract. Calc. Appl. Anal. 26, 1016–1030, 2023 (preprint available at arXiv)
	Sparse grid approximation in weighted Wiener spaces Yurii Kolomoitsev, Tetiana Lomako, Sergey Tikhonov J. Fourier Anal. Appl. 29, 19, 2023 (preprint available at arXiv)
	Uniform approximation by multivariate quasi-projection operators Yurii Kolomoitsev, Maria Skopina Anal. Math. Phys. 12, no. 2, Paper No. 68, 2022 (preprint available at arXiv)
	Approximation by quasi-interpolation operators and Smolyak's algorithm Yurii Kolomoitsev J. of Complexity 69, 101601, 2022 (preprint available at arXiv)
	Approximation properties of periodic multivariate quasi-interpolation operators Yurii Kolomoitsev, Jürgen Prestin J. Approx. Theory 270, 105631, 2021 (preprint available at arXiv)
	Asymptotics of the Lebesgue constants for bivariate approximation processes Yurii Kolomoitsev, Tetiana Lomako Appl. Math. Comput. 403, 126192, 2021 (preprint available at arXiv)
	Hardy-Littlewood and Ulyanov inequalities Yurii Kolomoitsev, Sergey Tikhonov Mem. Amer. Math. Soc. 271, no. 1325, 2021 (preprint available at arXiv)
	Asymptotics of the Lebesgue constants for a d-dimensional simplex Yurii Kolomoitsev, Elijah Liflyand Proc. Amer. Math. Soc. 149, 2911-2926, 2021 (preprint available at arXiv)
	Quasi-projection operators in the weighted Lp spaces Yurii Kolomoitsev, Maria Skopina Appl. Comput. Harmon. Anal. 52, 165-197, 2021 (preprint available at arXiv)
	Approximation by multivariate quasi-projection operators and Fourier multipliers Yurii Kolomoitsev, Maria Skopina Appl. Math. Comput. 400, 125955, 2021 (preprint available at arXiv)
	Smoothness of functions vs. smoothness of approximation processes Yurii Kolomoitsev, Sergey Tikhonov Bull. Math. Sci. 10, no. 3, 2030002, 2020 (preprint available at arXiv)
	Approximation by periodic multivariate quasi-projection operators Yurii Kolomoitsev, Aleksandr Krivoshein, Maria Skopina J. Math. Anal. Appl. 489, no. 2, 124192, 2020 (preprint available at arXiv)
	Properties of moduli of smoothness in Lp(Rd) Yurii Kolomoitsev, Sergey Tikhonov J. Approx. Theory 257, 105423, 2020 (preprint available at arXiv)
	Approximation by sampling-type operators in Lp-spaces Yurii Kolomoitsev, Maria Skopina Math. Methods Appl. Sciences 43, no. 16, 9358-9374, 2020 (preprint available at arXiv)