75 citations · 258 across the 15 of their papers we have counts for
24 papers
Dynamics of low energy wave packets in the one-dimensional quantum Heisenberg ferromagnet
Mateusz Kwaśnicki, Marcin Napiórkowski, Sören Petrat +1
Spin wave theory plays a central role in the analysis of low-energy properties of the quantum ferromagnetic Heisenberg model. In this work, we present a first step towards a rigoro…
Large time behavior of Lévy processes and their nonlocal Schrödinger semigroups
Mateusz Kwaśnicki, Phanuel Mariano, Hugo Panzo +1
We study the large time asymptotics of the Feynman-Kac semigroups of the symmetric Lévy process on unbounded open sets. Our main result proves the exact exponential asymptotic deca…
Bell-shaped functions are Poisson kernels
Mateusz Kwaśnicki
In a recent paper [Kwaśnicki, Poisson kernels on the half-plane are bell-shaped, Bull. London Math. Soc. 58 (2026), no. e70303], the author proved that Poisson kernels for a class…
Generalised eigenvector expansion of infinite Toeplitz matrices with absolutely/completely monotone entries
Mateusz Kwaśnicki, Jacek Wszoła
We study the spectral theory of infinite Toeplitz matrices under the assumption that and are completely monotone sequences. We derive expressio…
Boundary traces of shift-invariant diffusions in half-plane
Mateusz Kwaśnicki
We study boundary traces of shift-invariant diffusions: two-dimensional diffusions in the upper half-plane (or in ) invari…
Characterisation of the class of bell-shaped functions
Mateusz Kwaśnicki, Thomas Simon
A non-negative function is said to be 'bell-shaped' if tends to zero at and the -th derivative of changes its sign times for every $n = 0, 1, 2, \ld…
Harmonic extension technique for non-symmetric operators with completely monotone kernels
Mateusz Kwaśnicki
We identify a class of non-local integro-differential operators in with Dirichlet-to-Neumann maps in the half-plane for appropriate…
Random walks are determined by their trace on the positive half-line
Mateusz Kwaśnicki
We prove that the law of a random walk is determined by the one-dimensional distributions of for , as conjectured recently by Loïc Chaumont a…
Fluctuation theory for Lévy processes with completely monotone jumps
Mateusz Kwaśnicki
We study the Wiener-Hopf factorization for Lévy processes with completely monotone jumps. Extending previous results of L.C.G. Rogers, we prove that the space-time Wiener-Hop…
On the -norm of the discrete Hilbert transform
Rodrigo Bañuelos, Mateusz Kwaśnicki
Using a representation of the discrete Hilbert transform in terms of martingales arising from Doob -processes, we prove that its -norm, , is bounded above by th…
A new class of bell-shaped functions
Mateusz Kwaśnicki
We provide a large class of functions that are bell-shaped: the -th derivative of changes its sign exactly times. This class is described by means of Stieltjes-type…
Potential kernels, probabilities of hitting a ball, harmonic functions and the boundary Harnack inequality for unimodal Lévy processes
Tomasz Grzywny, Mateusz Kwaśnicki
In the first part of this article, we prove two-sided estimates of hitting probabilities of balls, the potential kernel and the Green function for a ball for general isotropic unim…
Pólya's conjecture fails for the fractional Laplacian
Mateusz Kwaśnicki, Richard S. Laugesen, Bartłomiej A. Siudeja
The analogue of Pólya's conjecture is shown to fail for the fractional Laplacian (-Delta)^{alpha/2} on an interval in 1-dimension, whenever 0 < alpha < 2. The failure is total: eve…
Contractivity and ground state domination properties for non-local Schrödinger operators
Kamil Kaleta, Mateusz Kwaśnicki, József Lőrinczi
We study supercontractivity and hypercontractivity of Markov semigroups obtained via ground state transformation of non-local Schrödinger operators based on generators of symmetric…
Asymptotic estimate of eigenvalues of pseudo-differential operators in an interval
Kamil Kaleta, Mateusz Kwaśnicki, Jacek Małecki
We prove a two-term Weyl-type asymptotic law, with error term O(1/n), for the eigenvalues of the operator psi(-Delta) in an interval, with zero exterior condition, for complete Ber…
Hitting times of points for symmetric Lévy processes with completely monotone jumps
Tomasz Juszczyszyn, Mateusz Kwaśnicki
Small-space and large-time estimates and asymptotic expansion of the distribution function and (the derivatives of) the density function of hitting times of points for symmetric Lé…
New families of subordinators with explicit transition probability semigroup
James Burridge, Mateusz Kwaśnicki, Alexey Kuznetsov +1
There exist only a few known examples of subordinators for which the transition probability density can be computed explicitly along side an expression for its Lévy measure and Lap…
Rogers functions and fluctuation theory
Mateusz Kwaśnicki
Extending earlier work by Rogers, Wiener-Hopf factorisation is studied for a class of functions closely related to Nevanlinna-Pick functions and complete Bernstein functions. The n…
Boundary Harnack inequality for Markov processes with jumps
Krzysztof Bogdan, Takashi Kumagai, Mateusz Kwaśnicki
We prove a boundary Harnack inequality for jump-type Markov processes on metric measure state spaces, under comparability estimates of the jump kernel and Urysohn-type property of…
On high spots of the fundamental sloshing eigenfunctions in axially symmetric domains
Tadeusz Kulczycki, Mateusz Kwaśnicki
We investigate the classical eigenvalue problem that arises in hydrodynamics and is referred to as the sloshing problem. It describes free liquid oscillations in a liquid container…
Suprema of Lévy processes
Mateusz Kwaśnicki, Jacek Małecki, Michał Ryznar
In this paper we study the supremum functional , where , , is a one-dimensional Lévy process. Under very mild assumptions we provide a simple…
Eigenvalues of the fractional Laplace operator in the interval
Mateusz Kwaśnicki
Two-term Weyl-type asymptotic law for the eigenvalues of one-dimensional fractional Laplace operator (-d^2/dx^2)^(alpha/2) (0 < alpha < 2) in the interval (-1,1) is given: the n-th…
Spectral properties of the Cauchy process
Tadeusz Kulczycki, Mateusz Kwaśnicki, Jacek Małecki +1
We study the spectral properties of the transition semigroup of the killed one-dimensional Cauchy process on the half-line (0,infty) and the interval (-1,1). This process is relate…
Boundary Harnack Inequality for alpha-harmonic functions on the Sierpiński triangle
Kamil Kaleta, Mateusz Kwaśnicki
We prove an uniform boundary Harnack inequality for nonnegative functions harmonic with respect to -stable process on the Sierpi{ń}ski triangle, where . Our result…