English
Related papers

Related papers: Approximation of starshaped sets using polynomials

200 papers

Black holes and neutron stars present extreme forms of matter that cannot be created as such in a laboratory on Earth. Instead, we have to observe and analyze the experiments that are ongoing in the Universe. The most telling observations…

Astrophysics · Physics 2008-11-26 Piet Hut , Shin Mineshige , Douglas C. Heggie , Junichiro Makino

The distance-resolved effective interaction between two star polymers in a good solvent is calculated by Molecular Dynamics computer simulations. The results are compared with a pair potential proposed recently by Likos et al. [Phys. Rev.…

Soft Condensed Matter · Physics 2009-10-31 A. Jusufi , M. Watzlawek , H. Loewen

Final representation of all those measures $\mu$ for which algebraic polynomials are dense in $L_p(R, d\mu)$ is found. The weighted analogue of the Weierstrass polynomial approximation theorem and a new version of the M. Krein's theorem…

Classical Analysis and ODEs · Mathematics 2007-05-23 Andrew G. Bakan

Cosmological N-Body simulations have become an essential tool for studying formation of large scale structure. These simulations are computationally challenging even though the available computing power gets better every year. A number of…

Astrophysics · Physics 2007-05-23 J. S. Bagla

We provide and describe a library of diffuse stellar radiation fields in spiral galaxies derived using calculations of the transfer of stellar radiation from the main morphological components - disks, thin disks, and bulges - through the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 C. C. Popescu , R. J. Tuffs

Let $F$ be a homogeneous polynomial in $S = \mathbb{C}[x_0,...,x_n]$. Our goal is to understand a particular polynomial decomposition of $F$; geometrically, we wish to determine when the hypersurface defined by $F$ in $\mathbb{P}^n$…

Algebraic Geometry · Mathematics 2012-04-13 Enrico Carlini , Elena Guardo , Adam Van Tuyl

We study continuous approximate solutions to polynomial equations over the ring $C(X)$ of continuous complex-valued functions over a compact Hausdorff space $X$. We show that when $X$ is one-dimensional, the existence of such approximate…

General Topology · Mathematics 2025-10-03 Joshua Lau , Vicente Marin-Marquez

Circumstellar disks are an essential ingredient of the formation of low-mass stars. It is unclear, however, whether the accretion-disk paradigm can also account for the formation of stars more massive than about 10 solar masses, in which…

Given a compact semialgebraic set S of R^n and a polynomial map f from R^n to R^m, we consider the problem of approximating the image set F = f(S) in R^m. This includes in particular the projection of S on R^m for n greater than m. Assuming…

Optimization and Control · Mathematics 2015-07-23 Victor Magron , Didier Henrion , Jean-Bernard Lasserre

Using the Newtonian approximation, we study rotating compact bosonic objects. The equations which describe stationary states with non-zero angular momentum are constructed and some numerical results are presented as examples. Limits on the…

Astrophysics · Physics 2009-10-28 Vanda Silveira , Claudio M. G. de Sousa

We give a polynomial-time constant-factor approximation algorithm for maximum independent set for (axis-aligned) rectangles in the plane. Using a polynomial-time algorithm, the best approximation factor previously known is $O(\log\log n)$.…

Computational Geometry · Computer Science 2021-07-07 Joseph S. B. Mitchell

Outcomes of numerical relativity simulations of massive core collapses or binary neutron star mergers with moderate masses suggest formations of rapidly and differentially rotating neutron stars. Subsequent fall back accretion may also…

High Energy Astrophysical Phenomena · Physics 2017-11-29 Koji Uryu , Antonios Tsokaros , Luca Baiotti , Filippo Galeazzi , Keisuke Taniguchi , Shin'ichirou Yoshida

We study the geometry of algebraic numbers in the complex plane, and their Diophantine approximation, aided by extensive computer visualization. Motivated by these images, called algebraic starscapes, we describe the geometry of the map…

Number Theory · Mathematics 2022-07-12 Edmund Harriss , Katherine E. Stange , Steve Trettel

We test the methods developed in previous papers for inferring the intrinsic shapes of elliptical galaxies, using simulated objects from N-body experiments. The shapes of individual objects are correctly reproduced to within the statistical…

Astrophysics · Physics 2009-10-31 T. S. Statler

We introduce a rigorous and general framework to study systematically self-gravitating elastic materials within general relativity, and apply it to investigate the existence and viability, including radial stability, of spherically…

General Relativity and Quantum Cosmology · Physics 2022-06-07 Artur Alho , José Natário , Paolo Pani , Guilherme Raposo

Let $D$ be the set of $n\times n$ positive semidefinite matrices of trace equal to one, also known as the set of density matrices. We prove two results on the hardness of approximating $D$ with polytopes. First, we show that if $0 <…

Optimization and Control · Mathematics 2022-06-14 Hamza Fawzi

This survey provides an exposition of a suite of techniques based on the theory of polynomials, collectively referred to as polynomial methods, which have recently been applied to address several challenging problems in statistical…

Statistics Theory · Mathematics 2021-04-22 Yihong Wu , Pengkun Yang

Walsh introduced a generalisation of Faber polynomials to certain compact sets which need not be connected. We derive several equivalent representations of these Faber-Walsh polynomials, analogous to representations of Faber polynomials.…

Complex Variables · Mathematics 2013-06-07 Olivier Sète

We formulate and discuss a necessary and sufficient condition for polynomials to be dense in a space of continuous functions on the real line, with respect to Bernstein's weighted uniform norm. Equivalently, for a positive finite measure…

Complex Variables · Mathematics 2011-11-01 Alexei Poltoratski

External occulters, otherwise known as starshades, have been proposed as a solution to one of the highest priority yet technically vexing problems facing astrophysics - the direct imaging and characterization of terrestrial planets around…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 Webster Cash