activity
20182026
most citedApproximate Lattices and Meyer Sets in Nilpotent Lie Groups

6 citations · 9 across the 9 of their papers we have counts for

collaborators

10 papers

math.DS2026

Applications of Almost Stationarity I: Quantitative Growth of Injectivity Radius and Stück-Zimmer Theorem

Ilya Gekhtman, Simon Machado, Omri Solan +1

Fraczyk and Gelander proved in \cite{FG} that for any simple Lie group of high rank and for every non-lattice discrete subgroup , the injectivity radius of points in $…

math.PR2026

invariant random subsets of

Mikołaj Frączyk, Simon Machado

We classify measures on , , the space of subsets of , which are invariant under all affine special linear transformations. In other…

math.RA2026

On the structure of approximate rings

Krzysztof Krupiński, Simon Machado

By a [-]approximate subring of a ring we mean an additively symmetric subset such that is covered by finitely many [resp.\ ] additive translates…

math.SP2023

Maximal multiplicity of Laplacian eigenvalues in negatively curved surfaces

Cyril Letrouit, Simon Machado

In this work, we obtain the first upper bound on the multiplicity of Laplacian eigenvalues for negatively curved surfaces which is sublinear in the genus g. Our proof relies on a t…

math.GR2023

The structure of approximate lattices in linear groups

Simon Machado

Approximate lattices are aperiodic generalisations of lattices of locally compact groups that were first studied in seminal work of Yves Meyer. They are defined as those uniformly…

math.GR2023

Small doubling for discrete subsets of non-commutative groups and a theorem of Lagarias

Simon Machado

Approximate lattices of Euclidean spaces, also known as Meyer sets, are aperiodic subsets with fascinating properties. In general, approximate lattices are defined as approximate s…

math.GR2020

Approximate Lattices in Higher-Rank Semi-Simple Groups

Simon Machado

We show that strong approximate lattices in higher-rank semi-simple algebraic groups are arithmetic.

math.GR2020★ 3 cited

Closed approximate subgroups: compactness, amenability and approximate lattices

Simon Machado

We investigate properties of closed approximate subgroups of locally compact groups, with a particular interest for approximate lattices i.e. those approximate subgroups that are d…

math.GR2019

Infinite Approximate Subgroups of Soluble Lie Groups

Simon Machado

We study infinite approximate subgroups of soluble Lie groups. Generalising a theorem of Fried and Goldman we show that approximate subgroups are close, in a sense to be defined, t…

math.GR2018★ 6 cited

Approximate Lattices and Meyer Sets in Nilpotent Lie Groups

Simon Machado

We show that uniform approximate lattices in nilpotent Lie groups are subsets of model sets. This extends a theorem due to Yves Meyer about quasicrystals in Euclidean spaces. To do…