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Related papers: New gaps on the Lagrange and Markov spectra

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We study the convergence rate to equilibrium for a family of Markov semigroups $\{\mathcal{P}_t^{\epsilon}\}_{\epsilon > 0}$ generated by a class of hypoelliptic stochastic differential equations on $\mathbb{R}^d$, including Galerkin…

Analysis of PDEs · Mathematics 2021-11-03 Jacob Bedrossian , Kyle Liss

We present the first high-resolution (R ~ 31,000) spectra of the cool sdL 2MASS0532, and what was originally identified as an early-type L subdwarf (sdL) LSR1610-0040. Our work, in combination with contemporaneous work by Cushing and Vacca,…

Astrophysics · Physics 2008-11-26 Ansgar Reiners , Gibor Basri

This paper presents a new Bayesian spectral unmixing algorithm to analyse remote scenes sensed via sparse multispectral Lidar measurements. To a first approximation, in the presence of a target, each Lidar waveform consists of a main peak,…

Several cosmic ray experiments have measured excesses in electrons and positrons, relative to standard backgrounds, for energies from ~ 10 GeV - 1 TeV. These excesses could be due to new astrophysical sources, but an explanation in which…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Spencer Chang , Lisa Goodenough

In the present paper we consider Riemannian coverings $(X,g) \to (M,g)$ with residually finite covering group $\Gamma$ and compact base space $(M,g)$. In particular, we give two general procedures resulting in a family of deformed coverings…

Mathematical Physics · Physics 2009-09-29 Fernando Lledó , Olaf Post

We report new nearby L and late-M dwarfs (d_phot <= 30 pc) discovered in our search for nearby ultracool dwarfs (I-J >= 3.0, later than M8.0) at low Galactic latitude (|b| < 15 degr) over 4,800 square degrees in the DENIS database. We used…

The experiments searching for a hidden gauge sector with a leptophilic neutral gauge boson have already ruled out $U(1)_{L_e-L_\mu}$ as a feasible extension of the Standard Model (SM) gauge group ($\mathcal{G}_{\rm SM}$) for explaining the…

High Energy Physics - Phenomenology · Physics 2025-01-28 Bibhabasu De

Brualdi and Hoffman proposed a well-known problem of determining the graph with maximum adjacency spectral radius among all graphs with given size $m$. Early work by Friedland and Stanley addressed some specific cases. This problem was…

Combinatorics · Mathematics 2026-04-30 Hongzhang Chen , Jianxi Li , Yongtao Li

Hidden Markov Models (HMMs) can be accurately approximated using co-occurrence frequencies of pairs and triples of observations by using a fast spectral method in contrast to the usual slow methods like EM or Gibbs sampling. We provide a…

Machine Learning · Statistics 2012-03-29 Dean P. Foster , Jordan Rodu , Lyle H. Ungar

We present a multi-wavelength physical characterization of 14 luminous Ly$\alpha$ emitters (LAEs) at $z\approx6$, integrating deep ground-based Magellan/M2FS spectroscopy with heterogeneous JWST/NIRCam broad- and medium-band imaging.…

Astrophysics of Galaxies · Physics 2026-05-15 Yuanhang Ning , Zheng Cai , Linhua Jiang , Yucheng Guo , Qiong Li , Si-Yue Yu , Xiaodi Yu , Zhen-Ya Zheng

Let $\varphi_0$ be a smooth area-preserving diffeomorphism of a compact surface $M$ and let $\Lambda_0$ be a horseshoe of $\varphi_0$ with Hausdorff dimension strictly smaller than one. Given a smooth function $f:M\to \mathbb{R}$ and a…

Dynamical Systems · Mathematics 2018-04-12 Aline Cerqueira , Carlos Matheus , Carlos Gustavo Moreira

We study the graph of the function $d(t)$ encoding the Hausdorff dimensions of the classical Lagrange and Markov spectra with half-infinite lines of the form $(-\infty, t)$. For this sake, we use the fact that the Hausdorff dimension of…

Number Theory · Mathematics 2026-04-24 Carlos Matheus , Carlos Gustavo Moreira , Polina Vytnova

In 1972, A. J. Hoffman proved his celebrated theorem concerning the limit points of spectral radii of non-negative symmetric integral matrices less than $\sqrt{2+\sqrt{5}}$. In this paper, after giving a new version of Hoffman's theorem, we…

Combinatorics · Mathematics 2020-12-29 Jianfeng Wang , Jing Wang , Maurizio Brunetti

We use new and published medium resolution 0.6--2.5 $\mu$m spectra of L and T dwarfs to develop a unified classification system for both of these new spectral classes. Two indices of the system at 1.2 $\mu$m and 1.5 $\mu$m are based on…

Astrophysics · Physics 2007-05-23 T. R. Geballe , G. R. Knapp , S. K. Leggett , X. Fan , D. A. Golimowski

We prove that the first gap of $\mathbb R$-complementary thresholds of surfaces is $\frac{1}{13}$. More precisely, the largest $\mathbb R$-complementary threshold for surfaces that is strictly less than $1$ is $\frac{12}{13}$. This result…

Algebraic Geometry · Mathematics 2023-05-31 Jihao Liu , V. V. Shokurov

We present a homogeneous sample of 1361 L and T dwarfs brighter than J = 17.5 (of which 998 are new), from an effective area of 3070 deg2, classified by the photo-type method to an accuracy of one spectral sub-type using izYJHKW1W2…

Instrumentation and Methods for Astrophysics · Physics 2016-04-13 N. Skrzypek , S. J. Warren , J. K. Faherty

In this paper we study the spectral properties of Markov-operator on $L^{2}$-spaces. Lawler and Sokal (Trans. Amer. Math. Soc., 1988, 309, pp. 557-580) used isoperimetric constants for discrete and continuous time Markov chains to obtain a…

Probability · Mathematics 2009-08-07 Achim Wuebker

In this article we study the differences of two consecutive eigenvalues $\lambda_{i}-\lambda_{i-1}$ up to $i=2g-2$ for the Laplacian on hyperbolic surfaces of genus $g$, and show that the supremum of such spectral gaps over the moduli space…

Differential Geometry · Mathematics 2024-05-22 Yunhui Wu , Haohao Zhang , Xuwen Zhu

Detection of sparse signals arises in a wide range of modern scientific studies. The focus so far has been mainly on Gaussian mixture models. In this paper, we consider the detection problem under a general sparse mixture model and obtain…

Information Theory · Computer Science 2012-11-13 T. Tony Cai , Yihong Wu

We develop a novel hyperspectral imaging system using structured illumination in an SLM-based Michelson interferometer. In our design, we use a reflective SLM as a mirror in one of the arms of a Michelson interferometer, and scan the…

Optics · Physics 2022-04-25 Amar Deo Chandra , Mintu Karmakar , Dibyendu Nandy , Ayan Banerjee
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