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Rapid advances in deep learning have brought not only myriad powerful neural networks, but also breakthroughs that benefit established scientific research. In particular, automatic differentiation (AD) tools and computational accelerators…

Instrumentation and Methods for Astrophysics · Physics 2024-02-13 Yin Li , Chirag Modi , Drew Jamieson , Yucheng Zhang , Libin Lu , Yu Feng , François Lanusse , Leslie Greengard

We propose a novel approach for parameterizing the luminosity distance, based on the use of rational "Pad\'e" approximations. This new technique extends standard Taylor treatments, overcoming possible convergence issues at high redshifts…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Alejandro Aviles , Alessandro Bravetti , Salvatore Capozziello , Orlando Luongo

The Planck satellite, along with several ground based telescopes, have mapped the cosmic microwave background (CMB) at sufficient resolution and signal-to-noise so as to allow a detection of the subtle distortions due to the gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-06 Ethan Anderes , Benjamin Wandelt , Guilhem Lavaux

In this study, we introduce a novel analytical Gaussian Process (GP) cosmography methodology, leveraging the differentiable properties of GPs to derive key cosmological quantities analytically. Our approach combines cosmic chronometer (CC)…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-19 Bikash R. Dinda

In this paper, by considering an absorption probability independent of photon wavelength, we show that current type Ia supernovae (SNe Ia) and gamma ray burst (GRBs) observations plus high-redshift measurements of the cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-07 R. F. L. Holanda , S. H. Pereira , Deepak Jain

We present an analytical approximation formula for the luminosity distance in spatially flat cosmologies with dust and a cosmological constant. Apart from the overall factor, the effect of non-zero cosmological constant in our formula is…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-03 Masaru Adachi , Masumi Kasai

We present jax-cosmo, a library for automatically differentiable cosmological theory calculations. It uses the JAX library, which has created a new coding ecosystem, especially in probabilistic programming. As well as batch acceleration,…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-01 Jean-Eric Campagne , François Lanusse , Joe Zuntz , Alexandre Boucaud , Santiago Casas , Minas Karamanis , David Kirkby , Denise Lanzieri , Yin Li , Austin Peel

Cosmological distances are fundamental observables in cosmology. The luminosity ($D_L$), angular diameter ($D_A$) and gravitational wave ($D_{\rm GW}$) distances are all trivially related in General Relativity assuming no significant…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-07 Isabela Matos , Miguel Quartin , Luca Amendola , Martin Kunz , Riccardo Sturani

We investigate higher order symplectic integration strategies within Bayesian cosmic density field reconstruction methods. In particular, we study the fourth-order discretisation of Hamiltonian equations of motion (EoM). This is achieved by…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-29 Mónica Hernández-Sánchez , Francisco-Shu Kitaura , Metin Ata , Claudio Dalla Vecchia

We study exact cosmological solutions in $f(Q)$ gravity formulated beyond the coincident gauge, focusing on the non-coincident connection branch $\Gamma_B$. Using a minisuperspace approach, the field equations are recast into an equivalent…

General Relativity and Quantum Cosmology · Physics 2025-09-18 Avik De , Andronikos Paliathanasis

Cosmography has been extensively utilized to constrain the kinematic state of the Universe using measured distances. In this work, we propose a new method to reconstruct coupling theories using the first kind of Chebyshev polynomial for two…

General Relativity and Quantum Cosmology · Physics 2024-12-06 Sai Swagat Mishra , N. S. Kavya , P. K. Sahoo , V. Venkatesha

The most recent cosmological observations indicate that the present universe is flat and vacuum dominated. In such a universe, the distance measurements are always difficult and involve numerical computations. In this paper, it is shown…

Astrophysics · Physics 2007-12-06 T. Wickramasinghe

The cosmic distance ladder is the succession of techniques by which it is possible to determine distances to astronomical objects. Here, we present a new method to build the cosmic distance ladder, going from local astrophysical…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-09 David Camarena , Valerio Marra

In this study, we apply the Analytical method of Blind Separation (ABS) of the cosmic microwave background (CMB) from foregrounds to estimate the CMB temperature power spectrum from multi-frequency microwave maps. We test the robustness of…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-21 Jian Yao , Le Zhang , Yuxi Zhao , Pengjie Zhang , Larissa Santos , Jun Zhang

Recently, cosmography emerged as a valuable tool to effectively describe the vast amount of astrophysical observations without relying on a specific cosmological model. Its model-independent nature ensures a faithful representation of data,…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-21 Alexandra T. Petreca , Micol Benetti , Salvatore Capozziello

In this paper, an analytic approximation method for highly nonlinear equations, namely the homotopy analysis method (HAM), is employed to solve some backward stochastic differential equations (BSDEs) and forward-backward stochastic…

Numerical Analysis · Mathematics 2018-01-25 Xiaoxu Zhong , Shijun Liao

Although many exoplanets have been indirectly detected over the last years, direct imaging of them with ground-based telescopes remains challenging. In the presence of atmospheric fluctuations, it is ambitious to resolve the high brightness…

Instrumentation and Methods for Astrophysics · Physics 2023-02-08 Jakob Roth , Gianluca Li Causi , Vincenzo Testa , Philipp Arras , Torsten A. Enßlin

Approximate Bayesian computation (ABC) using a sequential Monte Carlo method provides a comprehensive platform for parameter estimation, model selection and sensitivity analysis in differential equations. However, this method, like other…

Machine Learning · Statistics 2015-07-21 Sanmitra Ghosh , Srinandan Dasmahapatra , Koushik Maharatna

Most Machine Learning (ML) methods, from clustering to classification, rely on a distance function to describe relationships between datapoints. For complex datasets it is hard to avoid making some arbitrary choices when defining a distance…

Machine Learning · Statistics 2016-07-04 Gina Gruenhage , Manfred Opper , Simon Barthelme

Weak gravitational lensing is one of the few direct methods to map the dark-matter distribution on large scales in the Universe, and to estimate cosmological parameters. We study a Bayesian inference problem where the data covariance…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-01 Martin Kilbinger , Emille E. O. Ishida , Jessi Cisewski-Kehe