Searcharxiv⌕ Search

arXiv subjects

Jean-François Quint

Publications and source records attributed to Jean-François Quint.

11 recordsLinked to original sources

Strong non-arithmeticity for Zariski dense subsemigroups

We prove a non-arithmeticity property for the complex eigenvalues of a Zariski dense subsemigroups of real reductive algebraic groups. This property will be used in [7] in order to establish a local limit theorem for the operator norm of products of random matrices.

math.GR↗

Conditioned random walks on linear groups I: construction of the target harmonic measure

Our objective is to explore random walks on the general linear group, constrained to a specific domain, with a primary focus on establishing the conditioned local limit theorem. This paper represents the first step toward achieving this goal, specifically entailing the construction of a novel entity -- the target harmonic measure. This measure, together with the harmonic function, serves as a pivotal component in establishing the conditioned local limit theorem. Using a reversal identity, we introduce a reversed sequence characterized as a dual random walk with a perturbation depending on future observations. The investigation of such walks, which rely on future information, lies at the heart of this paper. To carry out this study, we develop an approach grounded in the finite-size approximation of perturbations, enabling us to simplify the investigation to an array of Markov chains with increasing dimensions.

math.PR↗

Conditioned random walks on linear groups II: local limit theorems

We investigate random walks on the general linear group constrained within a specific domain, with a focus on their asymptotic behavior. In a previous work [38], we constructed the associated harmonic measure, a key element in formulating the local limit theorem for conditioned random walks on groups. The primary aim of this paper is to prove this theorem. The main challenge arises from studying the conditioned reverse walk, whose increments, in the context of random walks on groups, depend on the entire future. To achieve our goal, we combine a Caravenna-type conditioned local limit theorem with the conditioned version of the central limit theorem for the reversed walk. The resulting local limit theorem is then applied to derive the local behavior of the exit time.

math.PR↗

Directional counting for regular languages

We explain how certain tools from convex analysis and probability theory may be used in order to obtain counting results for the number of words with prescribed frequencies of letters in regular languages.

math.CO↗

Conditioned limit theorems for hyperbolic dynamical systems

Let $(\mathbb X, T)$ be a subshift of finite type equipped with the Gibbs measure $ν$ and let $f$ be a real-valued Hölder continuous function on $\mathbb X$ such that $ν(f) = 0$. Consider the Birkhoff sums $S_n f = \sum_{k=0}^{n-1} f \circ T^{k}$, $n\geq 1$. For any $t \in \mathbb R$, denote by $τ_t^f$ the first time when the sum $t+ S_n f$ leaves the positive half-line for some $n\geq 1$. By analogy with the case of random walks with independent identically distributed increments, we study the asymptotic as $n\to\infty$ of the probabilities $ ν(x\in \mathbb X: τ_t^f(x)>n) $ and $ ν(x\in \mathbb X: τ_t^f(x)=n) $. We also establish integral and local type limit theorems for the sum $t+ S_n f(x)$ conditioned on the set $\{ x \in \mathbb X: τ_t^f(x)>n \}$.

math.DS↗

How far are p-adic Lie groups from algebraic groups?

We show that, in a weakly regular $p$-adic Lie group $G$, the subgroup $G_u$ spanned by the one-parameter subgroups of $G$ admits a Levi decomposition. As a consequence, there exists a regular open subgroup of $G$ which contains $G_u$.

math.GR↗

Percolation sur le système à trois points

The three dot system is an action by homeomorphisms of $\mathbb Z^2$ on a compact space, which invariant measures are supposed to satisfy rigidity properties analoguous to the ones of invariant measures of angle doubling and tripling on the circle. For such measures, we establish a dichotomy which is related to percolation properties.

math.DS↗

Analyse harmonique sur le graphe de Pascal

We prove a spectral decomposition theorem for a well-known self-similar graph, for some finite graphs which are quotients of this graph and for a compactification of it.

math.DS↗