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Related papers: Cosmographic analysis with Chebyshev polynomials

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The South Pole Telescope (SPT), using its third-generation camera, SPT-3G, is conducting observations of the cosmic microwave background (CMB) in temperature and polarization across approximately 10 000 deg$^2$ of the sky at 95, 150, and…

Marginal likelihoods for the cosmic expansion rates are evaluated using the `Constitution' data of 397 supernovas, thereby updating the results in some previous works. Even when beginning with a very strong prior probability that favors an…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Moncy V. John

For trigonometric series and series of Chebyshev polynomials, we defined trigonometric Hermite-Pad\'e and Hermite-Jacobi approximations, linear and nonlinear Hermite-Chebyshev approximations. We established criterion of the existence and…

Classical Analysis and ODEs · Mathematics 2025-07-22 A. P. Starovoitov , I. V. Kruglikov , T. M. Osnach

The constrained mock-Chebyshev least squares operator is a linear approximation operator based on an equispaced grid of points. Like other polynomial or rational approximation methods, it was recently introduced in order to defeat the Runge…

Numerical Analysis · Mathematics 2022-09-21 Francesco Dell'Accio , Federico Nudo

In this study, we use late-time probes, such as well-localized fast radio bursts (FRBs), baryon acoustic oscillations (BAO), supernovae (SNe), and cosmic chronometers (CC) to constrain cosmological parameters through a model-independent…

We use the machine learning techniques, for the first time, to study the background evolution of the universe in light of 30 cosmic chronometers. From 7 machine learning algorithms, using the principle of mean squared error minimization on…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-27 Deng Wang , Wei Zhang

A cosmological observable measured in a range of redshifts can be used as a probe of a set of cosmological parameters. Given the cosmological observable and the cosmological parameter, there is an optimum range of redshifts where the…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-07 L. Kazantzidis , L. Perivolaropoulos , F. Skara

We study the problem of approximately recovering a probability distribution given noisy measurements of its Chebyshev polynomial moments. This problem arises broadly across algorithms, statistics, and machine learning. By leveraging a…

Data Structures and Algorithms · Computer Science 2026-05-20 Cameron Musco , Christopher Musco , Lucas Rosenblatt , Apoorv Vikram Singh

In the framework of mapped pseudospectral methods, we introduce a new polynomial-type mapping function in order to describe accurately the dynamics of systems developing almost singular structures. Using error criteria related to the…

Computational Physics · Physics 2008-10-21 Adrian Alexandrescu , Alfonso Bueno-Orovio , Jose R. Salgueiro , Victor M. Perez-Garcia

In this work, we present independent determinations of cosmological parameters and new constraints on $f(T)$ cosmologies, employing two new catalogs related to HII galaxy Hubble and CMB distance priors, along with the local standard…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-13 Rodrigo Sandoval-Orozco , Celia Escamilla-Rivera , Rebecca Briffa , Jackson Levi Said

Harmonic Balance is one of the most popular methods for computing periodic solutions of nonlinear dynamical systems. In this work, we address two of its major shortcomings: First, we investigate to what extent the computational burden of…

Dynamical Systems · Mathematics 2023-03-30 Lukas Woiwode , Malte Krack

Attempts at constraining theories of late time accelerated expansion often assume broad priors for the parameters in their phenomenological description. Focusing on shift-symmetric scalar-tensor theories with standard gravitational wave…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-28 Dina Traykova , Emilio Bellini , Pedro G. Ferreira , Carlos García-García , Johannes Noller , Miguel Zumalacárregui

Since cosmology is no longer "the data-starved science", the problem of how to best analyze large data sets has recently received considerable attention, and Karhunen-Loeve eigenvalue methods have been applied to both galaxy redshift…

Astrophysics · Physics 2009-10-07 Max Tegmark , Andy Taylor , Alan Heavens

Systematic errors in the galaxy redshift distribution $n(z)$ can propagate to systematic errors in the derived cosmology. We characterize how the degenerate effects in tomographic bin widths and galaxy bias impart systematic errors on…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-12 Imran Hasan , Samuel J. Schmidt , Michael D. Schneider , J. Anthony Tyson

We propose a method for cosmographic measurements by combining gravitational lensing of the cosmic microwave background (CMB) with cosmic shear surveys. We cross-correlate the galaxy counts in the lens plane with two different source…

Astrophysics · Physics 2009-08-26 Sudeep Das , David N. Spergel

It is common practice in cosmology to model large-scale structure observables as lognormal random fields, and this approach has been successfully applied in the past to the matter density and weak lensing convergence fields separately. We…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-18 Henrique S. Xavier , Filipe B. Abdalla , Benjamin Joachimi

We present the cosmological distance errors achievable using the baryon acoustic oscillations as a standard ruler. We begin from a Fisher matrix formalism that is upgraded from Seo & Eisenstein (2003). We isolate the information from the…

Astrophysics · Physics 2011-02-11 Hee-Jong Seo , Daniel J. Eisenstein

The paper addresses parametric inequality systems described by polynomial functions in finite dimensions, where state-dependent infinite parameter sets are given by finitely many polynomial inequalities and equalities. Such systems can be…

Optimization and Control · Mathematics 2015-09-15 G. Li , B. S. Mordukhovich , T. T. A. Nghia , T. S. Pham

Persistent tension between low-redshift observations and the Cosmic Microwave Background radiation (CMB), in terms of two fundamental distance scales set by the sound horizon $r_d$ and the Hubble constant $H_0$, suggests new physics beyond…

The normal parameters are a non--linear transformation of the cosmological parameters whose likelihood function is very well--approximated by a normal distribution. This transformation serves as an extreme form of data compression allowing…

Astrophysics · Physics 2009-11-07 Mike Chu , Manoj Kaplinghat , Lloyd Knox