English
Related papers

Related papers: New gaps on the Lagrange and Markov spectra

200 papers

The spectral gap of the Neumann and Dirichlet Laplacians are each known to have a sharp positive lower bound among convex domains of a given diameter. Between these cases, for each positive value of the Robin parameter an analogous sharp…

Spectral Theory · Mathematics 2022-03-29 Derek Kielty

Latest Lattice results on $D$ form factors evaluation from first principles show that the standard model (SM) branching ratios prediction for the leptonic $D_s \to \ell \nu_\ell$ decays and the semileptonic SM branching ratios of the $D^0$…

High Energy Physics - Phenomenology · Physics 2015-06-15 J. Barranco , D. Delepine , V. Gonzalez Macias , L. Lopez-Lozano

We estimate the size of the spectral gap at zero for some Hermitian block matrices. Included are quasi-definite matrices, quasi-semidefinite matrices (the closure of the set of the quasi-definite matrices) and some related block matrices…

Spectral Theory · Mathematics 2016-01-15 Ivan Veselic , Kresimir Veselic

We present here medium resolution (\lambda /\Delta\lambda\sim1200) H- and K-band spectra of M type dwarf stars covering the wavelength range 1.50 - 1.80 {\mu}m and 1.95 - 2.45 {\mu}m. The sample includes 53 dwarf stars (M0V-M7V) from new…

Solar and Stellar Astrophysics · Physics 2021-07-30 Dhrimadri Khata , Soumen Mondal , Ramkrishna Das , Supriyo Ghosh , Samrat Ghosh

We perform a discrimination procedure with the spectral index diagram of TiO5 and CaH2+CaH3 to separate M giants from M dwarfs. Using the M giant spectra identified from the LAMOST DR1 with high signal-to-noise ratio (SNR), we have…

Astrophysics of Galaxies · Physics 2015-06-01 Jing Zhong , Sebastien Lepine , Jing Li , Li Chen , Jinliang Hou , Ming Yang , Guangwei Li , Yong Zhang , Yonghui Hou

Determining the maximal density $m_1(\mathbb{R}^2)$ of planar sets without unit distances is a fundamental problem in combinatorial geometry. This paper investigates lower bounds for this quantity. We introduce a novel approach to…

Metric Geometry · Mathematics 2025-04-14 Alexander Tolmachev

A theoretical investigation is made of the dispersion characteristics of plasmons in a two-dimensional periodic system of semiconductor (dielectric) cylinders embedded in a dielectric (semiconductor) background. We consider both square and…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Manvir S. Kushwaha

The space of light rays $\mathcal{N}$ of a conformal Lorentz manifold $(M,\mathcal{C})$ is, under some topological conditions, a manifold whose basic elements are unparametrized null geodesics. This manifold $\mathcal{N}$, strongly inspired…

General Relativity and Quantum Cosmology · Physics 2022-06-29 A. Bautista , A. Ibort , J. Lafuente

This paper investigates the problem of estimating three stellar atmospheric physical parameters and thirteen elemental abundances for medium-resolution spectra from Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST). Typical…

Solar and Stellar Astrophysics · Physics 2023-12-27 Xiangru Li , Xiaoyu Zhang , Shengchun Xiong , Yulong Zheng , Hui Li

It is known (E.L. Green (1997), O. Post (2003)) that for an arbitrary $m\in\mathbb{N}$ one can construct a periodic non-compact Riemannian manifold $M$ with at least $m$ gaps in the spectrum of the corresponding Laplace-Beltrami operator…

Spectral Theory · Mathematics 2011-11-01 Andrii Khrabustovskyi

We report our initial discovery of 73 new planetary nebulae (PNe) in the Large Magellanic Cloud (LMC) following confirmatory 2dF spectroscopy on the Anglo-Australian Telescope (AAT). Preliminary candidate sources come from a 10 per cent…

Astrophysics · Physics 2009-11-13 Warren A. Reid , Quentin A. Parker

We identify a new way to divide the $\delta$-neighborhood of surfaces $\mathcal{M}\subset\mathbb{R}^3$ into a finitely-overlapping collection of rectangular boxes $S$. We obtain a sharp $(l^2,L^p)$ decoupling estimate using this…

Classical Analysis and ODEs · Mathematics 2025-12-03 Larry Guth , Dominique Maldague , Changkeun Oh

The classic graphical Cheeger inequalities state that if $M$ is an $n\times n$ symmetric doubly stochastic matrix, then \[ \frac{1-\lambda_{2}(M)}{2}\leq\phi(M)\leq\sqrt{2\cdot(1-\lambda_{2}(M))} \] where…

Combinatorics · Mathematics 2019-09-30 Jenish C. Mehta , Leonard J. Schulman

We present the results and prospects for searches beyond the Standard Model (SM) at the LHC by the ATLAS and CMS collaborations. The minimal supersymmetric extension of the SM has been investigated in various configurations and lower limits…

High Energy Physics - Experiment · Physics 2019-08-13 Daniel Teyssier

Let $X$ be a simplicial complex on $n$ vertices without missing faces of dimension larger than $d$. Let $L_{j}$ denote the $j$-Laplacian acting on real $j$-cochains of $X$ and let $\mu_{j}(X)$ denote its minimal eigenvalue. We study the…

Combinatorics · Mathematics 2019-10-16 Alan Lew

We present a general approach to proving the existence of spectral gaps and asynchronous exponential growth for growth-fragmentation semigroups in moment spaces $L^{1}(\mathbb{R}_{+};\ x^{\alpha }dx)$ and $L^{1}(\mathbb{R} _{+};\ \left(…

Functional Analysis · Mathematics 2022-01-14 Mustapha Mokhtar-Kharroubi , Jacek Banasiak

The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) has obtained more than 23 million spectra, opening an unprecedented opportunity to study stellar physics, as well as the formation and evolution of our Milky Way. In…

Solar and Stellar Astrophysics · Physics 2024-07-19 Chun-qian Li , Jian-rong Shi , Hong-liang Yan , Zhong-rui Bai , Jiang-tao Wang , Ming-yi Ding

Let $\lambda(G)$ be the smallest number of vertices that can be removed from a non-empty graph $G$ so that the resulting graph has a smaller maximum degree. Let $\lambda_{\rm e}(G)$ be the smallest number of edges that can be removed from…

Combinatorics · Mathematics 2020-07-24 Peter Borg

Given parameters k, l, and d, we give new lower bounds on the dimensions N such that there are maps from R^d to R^N that are k-regular, l-skew embeddings, or k-regular-l-skew embeddings. This extends and sharpens results due to Chisholm…

Algebraic Topology · Mathematics 2014-09-04 Pavle V. M. Blagojevic , Wolfgang Lueck , Guenter M. Ziegler

The spread of a graph $G$ is the difference $\lambda_1 - \lambda_n$ between the largest and smallest eigenvalues of its adjacency matrix. Breen, Riasanovsky, Tait and Urschel recently determined the graph on $n$ vertices with maximum spread…

Combinatorics · Mathematics 2025-10-10 George Brooks , William Linz , Linyuan Lu