Prof. dr hab. Krzysztof Stempak

Address: room 1.12, building C-11
phone: 71 320 2529
e-mail:

harmonic analysis of orthogonal expansions;
classic harmonic analysis;
some aspects of functional analysis;
some aspects of Dunkl theory;
some aspects of partial differential equations.

I am also the author/coauthor of research papers from the operator theory, algebra and topology.

Selected publications

Mean summability methods for Laguerre series, Trans. Amer. Math. Soc. 322, (1990), 671-690.
On connections between Hankel, Laguerre and Heisenberg multipliers, J. London Math. Soc. 51, (1995), 286-298.
(with W. Trebels) On weighted transplantation and multipliers for Laguerre expansions, Math. Annalen 300, (1994), 203-219.
(with J. Zienkiewicz) Twisted convolutions and Riesz means, J. d'Anal. Math. 76, (1998), 93-107.
(with J.L. Torrea) Poisson integrals and Riesz transforms for Hermite function expansions with weights, J. Funct. Anal. 202, (2003), 443-472.
(with O. Ciaurri) Transplantation and multiplier theorems for Fourier-Bessel expansions, Trans. Amer. Math. Soc. 358, (2006), 4441-4465.
(with O. Ciaurri) Weighted transplantation for Fourier-Bessel series, J. d'Anal. Math. 100, (2006), 133-156.
(with A. Nowak) Riesz transforms and conjugacy for Laguerre expansions of Hermite type, J. Funct. Anal. 244, (2007), 399-443.
(with A. Nowak) Riesz transforms for multi-dimensional Laguerre function expansions, Advances in Math. 215, (2007), 642-678.
(with C.-C. Lin) Local Hardy-Littlewood maximal operator, Math. Annalen 348, (2010), 797-813.
(with A. Nowak) Potential operators associated with Hankel and Hankel-Dunkl transforms, J. d'Anal. Math. 131, (2017), 277-321.
The Laplacian with mixed Dirichlet-Neumann boundary conditions on Weyl chambers, J. Differ. Equations 329, (2022), 348-370.

and these in Studia Mathematica

An algebra associated with the generalized sublaplacian, Studia Math. 88, (1988), 245-256.
Almost everywhere summability of Laguerre series, Studia Math. 100, (1991), 129-147.
Almost everywhere summability of Laguerre series.II, Studia Math. 103, (1992), 317-327.
Equiconvergence for Laguerre function series, Studia Math. 118, (1996), 285-300.
(z W. Trebelsem) Hankel multipliers and transplantation operators, Studia Math. 126, (1997), 51-66.
(z O. Ciaurri) Conjugacy for Fourier-Bessel expansions, Studia Math. 176, (2006), 215-247.
(z J. Małeckim) Reflection principles for functions of Neumann and Dirichlet Laplacians on open reflection invariant subsets of R^d, Studia Math. 251, (2020), 171-193.
Finite reflection groups and symmetric extensions of Laplacian, Studia Math. 261, (2021), 241-267.

Hobby

I like sailing and kayaking during summers and skiing during winters. On Masurian Lakes (North-East of Poland) I sail since 1976; I was almost everywhere there, sailing also on such "exotic" lakes like: Gołdopiwo, Pozezdrze, Warnołty, Tyrkło (I did not enter Buwełno, Łuknajno and Tuchlin).

I kayaked the following rivers and kayak trails in Poland (some of them several times): Czarna Hańcza, Krutynia, Drawa, Gwda, Brda, Wda, Piława, Sapina, the Ostróda-Elbląg Channel, a part of Brodnica cirle.

29-th Conference on Fluid Dynamics

33-rd Conference on Mathematical modeling of wind