activity
20072026
most citedPure Point spectrum for measure dynamical systems on locally compact Abelian groups

41 citations · 310 across the 48 of their papers we have counts for

collaborators

53 papers

math-ph2026

Eberlein convolution as an inner product and quantitative Bombieri--Taylor results

Daniel Lenz, Nicolae Strungaru

We present a simple argument providing a very general Bombieri--Taylor-type result to compute Bragg peaks in diffraction theory as limits. At its abstract core the argument relies…

math-ph2026

Pseudorandomness and Diffraction

David Damanik, Nicolae Strungaru

Pseudorandom structures are structures that behave like random ones, without necessarily being random themselves. It is a prominent, and evidently very difficult, conjecture that $…

math.FA2026

Continuous diffraction spectrum and the uniform vanishing of Fourier--Bohr coefficients

Nicolae Strungaru

In this paper we review the connection among continuity of the diffraction spectrum, the (uniform) vanishing of the Fourier--Bohr coefficients and the so called consistent phase fr…

math.FA2026

On almost periodicity in crystalline measures

Jan Mazáč, Christoph Richard, Nicolae Strungaru

Meyer defined crystalline measures as tempered distributions such that both and its Fourier transform are pure-point Radon measures of locally finite support. H…

math.CO2026

The 1-2-3 conjecture for polygonal tilings

Alison Charlesworth, Christopher Ramsey, Nicolae Strungaru

The 1-2-3 conjecture has been solved positively in 2024 for finite graphs and by extension for infinite graphs which are locally finite. The solution is non-constructive, and findi…

math.DS2026

On the spectrum of non-ergodic measures

Michael Francis, Christopher Ramsey, Nicolae Strungaru

Consider a topological dynamical system where the group is abelian and the topologies are locally compact and second-countable. Given an invariant measure for this system, we show…

math.DS2025

Wiener--Wintner points for topological dynamical systems

Daniel Lenz, Nicolae Strungaru

We consider measurable and topological dynamical systems over locally compact abelian groups. Our main observation relates convergence of Wiener-Wintner type averages to eigenvalue…

math-ph2024

Twice Fourier transformable measures and diffraction theory

Hans G. Feichtinger, Christoph Richard, Christoph Schumacher +1

Mathematical diffraction theory has been developed since about 1995. Hof's initial approach relied on tempered distributions in euclidean space. Nowadays often the Fourier theory b…

math-ph2024

Which Meyer sets are regular model sets? A characterization via almost periodicity

Daniel Lenz, Christoph Richard, Nicolae Strungaru

In 2012, Meyer introduced the notions of generalized almost periodic measure and almost periodic pattern and proved that regular model sets in Euclidean space are almost periodic p…

math.CO2024

Relative position in binary substitutions

Michael Coons, Christopher Ramsey, Nicolae Strungaru

Given an infinite word on a finite alphabet, an immediate question arises:~can we understand the frequency of letters in \,? For words that are the fixed points…

math.FA2024

Diffraction of the primes and other sets of zero density

Adam Humeniuk, Christopher Ramsey, Nicolae Strungaru

In this paper, we show that the diffraction of the primes is absolutely continuous, showing no bright spots (Bragg peaks). We introduce the notion of counting diffraction, extendin…

math.CA2024

Circles in diffraction

Emily R. Korfanty, Nicolae Strungaru

Given a Fourier transformable measure in two dimensions, we find a formula for the intensity of its Fourier transform along circles. In particular, we obtain a formula for the diff…

math.FA2024

Diffraction as a unitary representation and the orthogonality of measures with respect to the reflected Eberlein convolution

Daniel Lenz, Nicolae Strungaru

We discuss how the diffraction theory of a single translation bounded measure or a family of such measures can be understood within the framework of unitary group representations.…

math-ph2023

Pure point diffraction and almost periodicity

Daniel Lenz, Timo Spindeler, Nicolae Strungaru

This article deals with pure point diffraction and its connection to various notions of almost periodicity. We explain why the Fibonacci chain does not fit into the classical class…

math.CO2023

Generating functions of substitutions

Aisling Pouti, Christopher Ramsey, Nicolae Strungaru

In this paper we study substitutions and some of their associated generating functions. This association takes aperiodicity to transcendence, and vice-versa. These generating funct…

math.FA2022

The (twisted) Eberlein convolution of measures

Daniel Lenz, Timo Spindeler, Nicolae Strungaru

In this paper, we study the properties of the Eberlein convolution of measures and introduce a twisted version of it. For functions we show that the twisted Eberlein convolution ca…

math-ph2022★ 1 cited

Inter model sets in are model sets

Christoph Richard, Nicolae Strungaru

We show that any translate of a model set is a model set in some modified cut-and-project scheme. Restricting to Euclidean direct space, we show that any translate of an inter mode…

math.CO2022

Colourings of aperiodic tilings

Molly Evans, Dylan Gawlak, Christopher Ramsey +2

We find explicit optimal vertex, edge and face coulourings for the chair tiling, the Ammann--Beenker tiling, the rational pinwheel tiling and the pinwheel tiling.

math.FA2022

Abstract almost periodicity for group actions on uniform topological spaces

Daniel Lenz, Timo Spindeler, Nicolae Strungaru

We present a unified theory for the almost periodicity of functions with values in an arbitrary Banach space, measures and distributions via almost periodic elements for the action…

math.FA2022★ 5 cited

A note on tempered measures

Michael Baake, Nicolae Strungaru

The relation between tempered distributions and measures is analysed and clarified. While this is straightforward for positive measures, it is surprisingly subtle for signed or com…

math.CA2021

Fourier Transformable Measures with Meyer set support and their lift to the cut and project scheme

Nicolae Strungaru

In this paper, we prove that given a cut-and-project scheme and a compact window , the natural projection gives a bijection between the Fourier…

math.FA2021

Semi-measures and their Fourier transform

Timo Spindeler, Nicolae Strungaru

The basic theory of semi-measures on locally compact Abelian groups is extended to prove the existence of a generalised Eberlein decomposition into such semi-measures.

math.CA2021

On the orthogonality of measures of different spectral type with respect to twisted Eberlein convolution

Nicolae Strungaru

In this paper we show that under suitable conditions on their Fourier--Bohr coefficients, the twisted Eberlein convolution of a measure with pure point diffraction spectra and a me…

math.DS2021★ 3 cited

Spectrum of weak model sets with Borel windows

Gerhard Keller, Christoph Richard, Nicolae Strungaru

Consider the extended hull of a weak model set together with its natural shift action. Equip the extended hull with the Mirsky measure, which is a certain natural pattern frequency…