activity
20092026
most citedCounterexamples, covering systems, and zero-one laws for inhomogeneous approximation

13 citations · 22 across the 15 of their papers we have counts for

collaborators

18 papers

math.DS2026

Straight-line trajectories on the Mucube

Andre Oliveira, Felipe A. Ramírez, Chandrika Sadanand +1

The dynamics of straight line flows on compact half-translation surfaces (surfaces formed by gluing Euclidean polygons edge-to-edge via translations possibly composed with rotation…

math.NT2026

Duffin--Schaeffer examples, real residue systems, and Bohr-set primes

Stefan M. Hesseling, Felipe A. Ramirez

We prove the following generalization of a well-known result of Duffin and Schaeffer: For any given countable sets and $Z\subset\mathbb{R}\setminus\operatorna…

math.NT2024

The Duffin-Schaeffer conjecture with a moving target

Manuel Hauke, Felipe A. Ramirez

We prove the inhomogeneous generalization of the Duffin-Schaeffer conjecture in dimension . That is, given and $ψ:\mathbb{N}\to\mathbb{R}_{\g…

math.NT2024

Metric bootstraps for limsup sets

Felipe A. Ramirez

In metric Diophantine approximation, one frequently encounters the problem of showing that a limsup set has positive or full measure. Often it is a set of points in -dimensional…

math.NT2023★ 1 cited

Inhomogeneous approximation for systems of linear forms with primitivity constraints

Demi Allen, Felipe A. Ramirez

We study (inhomogeneous) approximation for systems of linear forms using integer points which satisfy additional primitivity constraints. The first family of primitivity constraint…

math.NT2022

The Duffin--Schaeffer conjecture for systems of linear forms

Felipe A. Ramirez

We extend the Duffin--Schaeffer conjecture to the setting of systems of linear forms in variables. That is, we establish a criterion to determine whether, for a given rate…

math.NT2021

Independence inheritance and Diophantine approximation for systems of linear forms

Demi Allen, Felipe A. Ramirez

The classical Khintchine-Groshev theorem is a generalization of Khintchine's theorem on simultaneous Diophantine approximation, from approximation of points in to app…

math.NT2021

Diophantine approximation in metric space

Jonathan M. Fraser, Henna Koivusalo, Felipe A. Ramirez

Diophantine approximation is traditionally the study of how well real numbers are approximated by rationals. We propose a model for studying Diophantine approximation in an arbitra…

math.NT2020

Remarks about inhomogeneous pair correlations

Felipe A. Ramirez

Given an infinite subset , let denote its smallest elements. There is a rich and growing literature on the question of whether for typical $α…

math.NT2020

Dirichlet is not just Bad and Singular

Victor Beresnevich, Lifan Guan, Antoine Marnat +2

It is well known that in dimension one the set of Dirichlet improvable real numbers consists precisely of badly approximable and singular numbers. We show that in higher dimensions…

math.NT2020

A note on sequences not having metric Poissonian pair correlations

Felipe A. Ramirez

The purpose of this note is to present a construction of sequences which do not have metric Poissonian pair correlations (MPPC) and whose additive energies grow at rates that come…

math.NT2015★ 13 cited

Counterexamples, covering systems, and zero-one laws for inhomogeneous approximation

Felipe A. Ramirez

We develop the inhomogeneous counterpart to some key aspects of the story of the Duffin--Schaeffer Conjecture (1941). Specifically, we construct counterexamples to a number of cand…

math.DS2014

Recurrence to shrinking targets on typical self-affine fractals

Henna Koivusalo, Felipe A. Ramírez

We explore the problem of finding the Hausdorff dimension of the set of points that recur to shrinking targets on a self-affine fractal. To be exact, we study the dimension of a ce…

math.DS2013

Higher cohomology of parabolic actions on certain homogeneous spaces

Felipe A. Ramirez

We show that for a parabolic R^d-action on a compact quotient of PSL(2,R)^d, the cohomologies in degrees 1 through d-1 trivialize, and we give the obstructions to solving the degre…

math.DS2012★ 3 cited

Invariant distributions and cohomology for geodesic flows and higher cohomology of higher-rank Anosov actions

Felipe A. Ramirez

We are motivated by a conjecture of A. and S. Katok to study the smooth cohomologies of a family of Weyl chamber flows. The conjecture is a natural generalization of the Livshitz T…

math.DS2012

Limit theorems for rank-one Lie groups

Alexander Gorodnik, Felipe A. Ramirez

We investigate asymptotic behaviour of averaging operators for actions of simple rank-one Lie groups. It was previously known that these averaging operators converge almost everywh…

math.DS2011★ 3 cited

Higher cohomology for Anosov actions on certain homogeneous spaces

Felipe A. Ramirez

We study the smooth untwisted cohomology with real coefficients for the action on [SL(2, R) \times \cdot \cdot \cdot \times SL(2, R)]/Γ by the subgroup of diagonal matrices, where…

math.DS2009★ 2 cited

Cocycles over higher-rank abelian actions on quotients of semisimple Lie groups

Felipe A. Ramirez

We study actions by higher-rank abelian groups on quotients of semisimple Lie groups with finite center. First, we consider actions arising from the flows of two commuting elements…