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In this paper we study multi-parameter projection theorems for fractal sets. With the help of these estimates, we recover results about the size of $A \cdot A+...+A \cdot A$, where $A$ is a subset of the real line of a given Hausdorff…

Classical Analysis and ODEs · Mathematics 2011-06-29 B. Erdoğan , D. Hart , A. Iosevich

We prove that the set of $n$-point configurations for which the solution of the planar Steiner problem is not unique has the Hausdorff dimension at most $2n-1$ (as a subset of $\mathbb{R}^{2n}$). Moreover, we show that the Hausdorff…

Metric Geometry · Mathematics 2023-03-22 Mikhail Basok , Danila Cherkashin , Nikita Rastegaev , Yana Teplitskaya

We measure three-dimensional bispectra of halo intrinsic alignments (IA) and dark matter overdensities in real space from N-body simulations for halos of mass $10^{12}-10^{12.5} M_\odot /h$. We show that their multipoles with respect to the…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-10 Thomas Bakx , Toshiki Kurita , Alexander Eggemeier , Nora Elisa Chisari , Zvonimir Vlah

This paper is about lower and upper bounds for the Hausdorff dimension of the level and collision sets of a class of Feller processes. Our approach is motivated by analogous results for L\'evy processes by Hawkes (for level sets), Taylor…

Probability · Mathematics 2015-10-22 Victoria Knopova , René L. Schilling

We present a way to study the conformal structure of random planar maps. The main idea is to explore the map along an SLE (Schramm--Loewner evolution) process of parameter $ \kappa = 6$ and to combine the locality property of the SLE_{6}…

Probability · Mathematics 2014-08-20 Nicolas Curien

In this paper, we are concerned with the precise relationship between the Hausdorff dimension of possible singular point set $\mathcal{S}$ of suitable weak solutions and the parameter $\alpha$ in the nonlinear term in the following…

Analysis of PDEs · Mathematics 2022-05-02 Yanqing Wang , Yike Huang , Gang Wu , Daoguo Zhou

The Krasnoselskii-Mann iteration is an important algorithm in optimization and variational analysis for finding fixed points of nonexpansive mappings. In the general case, it produces a sequence converging \emph{weakly} to a fixed point…

Optimization and Control · Mathematics 2026-03-24 Sedi Bartz , Heinz H. Bauschke , Yuan Gao

Let M be a random (alpha n) x n matrix of rank r<<n, and assume that a uniformly random subset E of its entries is observed. We describe an efficient algorithm that reconstructs M from |E| = O(rn) observed entries with relative root mean…

Machine Learning · Computer Science 2009-09-17 Raghunandan H. Keshavan , Andrea Montanari , Sewoong Oh

We construct large Salem sets avoiding patterns, complementing previous constructions of pattern avoiding sets with large Hausdorff dimension. For a (possibly uncountable) family of uniformly Lipschitz functions $\{ f_i :…

Classical Analysis and ODEs · Mathematics 2026-01-14 Jacob Denson

A $k$-configuration is a collection of $k$ distinct integers $x_1,\ldots,x_k$ together with their pairwise arithmetic means $\frac{x_i+x_j}{2}$ for $1 \leq i < j \leq k$. Building on recent work of Filmus, Hatami, Hosseini and Kelman on…

Number Theory · Mathematics 2025-01-20 Adrian Beker

We define the quantile set of order $\alpha \in \left[ 1/2,1\right) $ associated to a law $P$ on $\mathbb{R}^{d}$ to be the collection of its directional quantiles seen from an observer $O\in \mathbb{R}^{d}$. Under minimal assumptions these…

Statistics Theory · Mathematics 2016-12-06 Adil Ahidar-Coutrix , Philippe Berthet

We present a framework to define a large class of neural networks for which, by construction, training by gradient flow provably reaches arbitrarily low loss when the number of parameters grows. Distinct from the fixed-space global…

Optimization and Control · Mathematics 2025-01-13 David A. R. Robin , Kevin Scaman , Marc Lelarge

Let ${\mathfrak M}=({\mathcal M},\rho)$ be a metric space and let $X$ be a Banach space. Let $F$ be a set-valued mapping from ${\mathcal M}$ into the family ${\mathcal K}_m(X)$ of all compact convex subsets of $X$ of dimension at most $m$.…

Functional Analysis · Mathematics 2021-02-19 Pavel Shvartsman

For every pattern $P$, consisting of a finite set of points in the plane, $S_{P}(n,m)$ is defined as the largest number of similar copies of $P$ among sets of $n$ points in the plane without $m$ points on a line. A general construction,…

Combinatorics · Mathematics 2011-02-28 Bernardo M. Ábrego , Silvia Fernández-Merchant

It turns out that a parametrization of degenerate density matrices requires a parametrization of $\mathfrak{F}=U(n)/({U(k_1)\times U(k_2)\times \cdots \times U(k_m)})\quad n=k_1 +\cdots + k_m $ where $U(k)$ denotes the set of all unitary…

Mathematical Physics · Physics 2017-09-13 Erwin Brüning , Shigeaki Nagamachi

We consider certain parametrised families of piecewise expanding maps on the interval, and estimate and sometimes calculate the Hausdorff dimension of the set of parameters for which the orbit of a fixed point has a certain shrinking target…

Dynamical Systems · Mathematics 2019-02-20 Magnus Aspenberg , Tomas Persson

We show that, up to Morita equivalence, any finite-dimensional algebra with a suitable homological system, admits an exact Borel subalgebra. This generalizes a theorem by Koenig, K\"ulshammer and Ovsienko, which holds for quasi-hereditary…

Representation Theory · Mathematics 2020-12-29 Raymundo Bautista Ramos , Jesús Efrén Pérez Terrazas , Leonardo Salmerón Castro

We extend the structure theory of Burago--Gromov--Perelman for Alexandrov spaces with curvature bounded below, to the setting of Busemann spaces with non-negative curvature. We prove that any finite-dimensional Busemann space with…

Metric Geometry · Mathematics 2026-04-20 Bang-Xian Han , Liming Yin

We show that the de Bruijn-Erd\H{o}s condition for the error term in their improvement of Fekete's Lemma is not only sufficient but also necessary in the following strong sense. Suppose that given a sequence $0\leq f(1)\leq f(2)\leq…

Combinatorics · Mathematics 2018-10-30 Zoltan Furedi , Imre Z. Ruzsa

It is well-known (see Dvoretzky, Erd{\H o}s and Kakutani [8] and Le Gall [12]) that a planar Brownian motion $(B_t)_{t\ge 0}$ has points of infinite multiplicity, and these points form a dense set on the range. Our main result is the…

Probability · Mathematics 2021-05-03 Elie Aïdékon , Yueyun Hu , Zhan Shi