451 research outputs found

    A Note on Rate of Convergence in Probability to Semicircular Law

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    In the present paper, we prove that under the assumption of the finite sixth moment for elements of a Wigner matrix, the convergence rate of its empirical spectral distribution to the Wigner semicircular law in probability is O(n1/2)O(n^{-1/2}) when the dimension nn tends to infinity.Comment: 13 page

    Convergence of the empirical spectral distribution function of Beta matrices

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    Let Bn=Sn(Sn+αnTN)1\mathbf{B}_n=\mathbf {S}_n(\mathbf {S}_n+\alpha_n\mathbf {T}_N)^{-1}, where Sn\mathbf {S}_n and TN\mathbf {T}_N are two independent sample covariance matrices with dimension pp and sample sizes nn and NN, respectively. This is the so-called Beta matrix. In this paper, we focus on the limiting spectral distribution function and the central limit theorem of linear spectral statistics of Bn\mathbf {B}_n. Especially, we do not require Sn\mathbf {S}_n or TN\mathbf {T}_N to be invertible. Namely, we can deal with the case where p>max{n,N}p>\max\{n,N\} and p<n+Np<n+N. Therefore, our results cover many important applications which cannot be simply deduced from the corresponding results for multivariate FF matrices.Comment: Published at http://dx.doi.org/10.3150/14-BEJ613 in the Bernoulli (http://isi.cbs.nl/bernoulli/) by the International Statistical Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm

    Circle packings and total geodesic curvatures in hyperbolic background geometry

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    In this paper, we study a new type of circle packings in hyperbolic background geometry. Horocycles and hypercycles are also considered in this packing. We give the existence and rigidity of this type of circle packing with conical singularities in terms of the total geodesic curvature. Moreover, we introduce the combinatorial curvature flow on surfaces to find the desired circle packing with the prescribed total geodesic curvature

    Hyperbolic Circle Packings and Total Geodesic Curvatures on Surfaces with Boundary

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    This paper investigates a generalized hyperbolic circle packing (including circles, horocycles or hypercycles) with respect to the total geodesic curvatures on the surface with boundary. We mainly focus on the existence and rigidity of circle packing whose contact graph is the 11-skeleton of a finite polygonal cellular decomposition, which is analogous to the construction of Bobenko and Springborn [4]. Motivated by Colin de Verdi\`ere's method [6], we introduce the variational principle for generalized hyperbolic circle packings on polygons. By analyzing limit behaviours of generalized circle packings on polygons, we give an existence and rigidity for the generalized hyperbolic circle packing with conical singularities regarding the total geodesic curvature on each vertex of the contact graph. As a consequence, we introduce the combinatoral Ricci flow to find a desired circle packing with a prescribed total geodesic curvature on each vertex of the contact graph.Comment: 26 pages, 7 figure

    LHMap-loc: Cross-Modal Monocular Localization Using LiDAR Point Cloud Heat Map

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    Localization using a monocular camera in the pre-built LiDAR point cloud map has drawn increasing attention in the field of autonomous driving and mobile robotics. However, there are still many challenges (e.g. difficulties of map storage, poor localization robustness in large scenes) in accurately and efficiently implementing cross-modal localization. To solve these problems, a novel pipeline termed LHMap-loc is proposed, which achieves accurate and efficient monocular localization in LiDAR maps. Firstly, feature encoding is carried out on the original LiDAR point cloud map by generating offline heat point clouds, by which the size of the original LiDAR map is compressed. Then, an end-to-end online pose regression network is designed based on optical flow estimation and spatial attention to achieve real-time monocular visual localization in a pre-built map. In addition, a series of experiments have been conducted to prove the effectiveness of the proposed method. Our code is available at: https://github.com/IRMVLab/LHMap-loc.Comment: Accepted by 2024 IEEE International Conference on Robotics and Automation (ICRA 2024
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