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In this paper, we use quasars calibrated from type Ia supernova (SN Ia) to constrain cosmological models. We consider three different X-ray luminosity ($L_{X}$) - ultraviolet luminosity ($L_{UV}$) relations of quasars, i.e., the standard…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-14 Haixiang Zhang , Yang Liu , Hongwei Yu , Xiaodong Nong , Nan Liang , Puxun Wu

In many scenarios, it is necessary to monitor a complex system via a time-series of observations and determine when anomalous exogenous events have occurred so that relevant actions can be taken. Determining whether current observations are…

Machine Learning · Computer Science 2022-09-20 Alex Mallen , Christoph A. Keller , J. Nathan Kutz

We use cosmography to present constraints on the kinematics of the Universe, without postulating any underlying theoretical model. To this end, we use a Monte Carlo Markov Chain analysis to perform comparisons to the supernova Ia Union 2…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Alejandro Aviles , Christine Gruber , Orlando Luongo , Hernando Quevedo

To efficiently probe primordial non-Gaussianity using Cosmic Microwave Background (CMB) data, we require theoretical predictions that are factorizable, \textit{i.e.}\ those whose kinematic dependence can be separated. This property does not…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-25 Oliver H. E. Philcox , Kunhao Zhong , Salvatore Samuele Sirletti

Deep learning is a powerful analysis technique that has recently been proposed as a method to constrain cosmological parameters from weak lensing mass maps. Due to its ability to learn relevant features from the data, it is able to extract…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-26 Janis Fluri , Tomasz Kacprzak , Aurelien Lucchi , Alexandre Refregier , Adam Amara , Thomas Hofmann

We present a proof of concept for a new algorithm which can be used to detect exoplanets in high contrast images. The algorithm properly combines mutliple observations acquired during different nights, taking into account the orbital motion…

Instrumentation and Methods for Astrophysics · Physics 2018-08-01 M. Nowak , H. Le Coroller , L. Arnold , K. Dohlen , D. Estevez , T. Fusco , J. -F. Sauvage , A. Vigan

Combining measurements on the expansion history of the Universe and on the growth rate of cosmic structures is key to discriminate between alternative cosmological frameworks and to test gravity. Recently, Linder (2017) proposed a new…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-16 Michele Moresco , Federico Marulli

Given the growth in the variety and precision of astronomical datasets of interest for cosmology, the best cosmological constraints are invariably obtained by combining data from different experiments. At the likelihood level, one…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-04 Arrykrishna Mootoovaloo , Carlos García-García , David Alonso , Jaime Ruiz-Zapatero

Despite their successes in the field of self-learning AI, Convolutional Neural Networks (CNNs) suffer from having too many trainable parameters, impacting computational performance. Several approaches have been proposed to reduce the number…

Machine Learning · Computer Science 2019-02-28 Sebastiaan Koning , Caspar Greeven , Eric Postma

Convolutional Neural Networks (CNNs) have recently been applied to cosmological fields -- weak lensing mass maps and galaxy maps. However, cosmological maps differ in several ways from the vast majority of images that CNNs have been tested…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-05 Kunhao Zhong , Marco Gatti , Bhuvnesh Jain

The study of cosmic expansion history and the late time cosmic acceleration from observational data depends on the nuisance parameters associated with the data. For example, the absolute peak magnitude of type Ia supernova associated with…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-19 Bikash R. Dinda

The growing field of large-scale time domain astronomy requires methods for probabilistic data analysis that are computationally tractable, even with large datasets. Gaussian Processes are a popular class of models used for this purpose…

Instrumentation and Methods for Astrophysics · Physics 2017-11-15 Daniel Foreman-Mackey , Eric Agol , Sivaram Ambikasaran , Ruth Angus

We present an algorithm that uses the distribution of photon arrival times to distinguish speckles from incoherent sources, like planets and disks, in high contrast images. Using simulated data, we show that our approach can overcome the…

Instrumentation and Methods for Astrophysics · Physics 2019-10-09 Alex B. Walter , Clinton Bockstiegel , Timothy D. Brandt , Benjamin A. Mazin

Recent studies of optimization methods and GNC of spacecraft near small bodies focusing on descent, landing, rendezvous, etc., with key safety constraints such as line-of-sight conic zones and soft landings have shown promising results;…

Optimization and Control · Mathematics 2020-05-22 Steven van Leeuwen

This study explores the application of autoencoder-based machine learning techniques for anomaly detection to identify exoplanet atmospheres with unconventional chemical signatures using a low-dimensional data representation. We use the…

Earth and Planetary Astrophysics · Physics 2026-01-06 Alexander Roman , Emilie Panek , Roy T. Forestano , Eyup B. Unlu , Katia Matcheva , Konstantin T. Matchev

In this paper, we propose a sampling algorithm based on state-of-the-art statistical machine learning techniques to obtain conditional nonlinear optimal perturbations (CNOPs), which is different from traditional (deterministic) optimization…

Optimization and Control · Mathematics 2024-03-26 Bin Shi , Guodong Sun

The direct imaging of potentially habitable exoplanets is one prime science case for high-contrast imaging instruments on extremely large telescopes. Most such exoplanets orbit close to their host stars, where their observation is limited…

Instrumentation and Methods for Astrophysics · Physics 2026-05-27 Jalo Nousiainen , Iremsu Taskin , Markus Kasper , Gilles Orban De Xivry , Olivier Absil

In this paper, we place constraints on four alternative cosmological models under the assumption of the spatial flatness of the Universe: CPL, EDE, GCG and MPC. A new compilation of 120 compact radio quasars observed by very-long-baseline…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-08 Xiaolei Li , Shuo Cao , Xiaogang Zheng , Jingzhao Qi , Marek Biesiada , Zong-Hong Zhu

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

Recent studies using four-point correlations suggest a parity violation in the galaxy distribution, though the significance of these detections is sensitive to the choice of simulation used to model the noise properties of the galaxy…

Instrumentation and Methods for Astrophysics · Physics 2024-05-24 Matthew Craigie , Peter L. Taylor , Yuan-Sen Ting , Carolina Cuesta-Lazaro , Rossana Ruggeri , Tamara M. Davis