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Quasars are variable and their variability can both constrain their physical properties and help to identify them. We look for ways to efficiently identify quasars exhibiting consistent variability over multi-year time-scales, based on a…

Astrophysics of Galaxies · Physics 2025-07-02 E. A. Zaharieva , V. D. Ivanov , E. P. Ovcharov , O. I. Stanchev

There have recently been several reports of apparently periodic variations in the light curves of quasars, e.g. PG 1302-102 by Graham et al. (2015a). Any quasar showing periodic oscillations in brightness would be a strong candidate to be a…

Instrumentation and Methods for Astrophysics · Physics 2016-07-27 S. Vaughan , P. Uttley , A. G. Markowitz , D. Huppenkothen , M. J. Middleton , W. N. Alston , J. D. Scargle , W. M. Farr

Based on the central limit theorem, we discuss the problem of evaluation of the statistical error of Monte Carlo calculations using a time discretized diffusion process. We present a robust and practical method to determine the effective…

Computational Physics · Physics 2017-02-22 François Delyon , Bernard Bernu , Markus Holzmann

High resolution spectra of quasar absorption systems provide the best constraints on temporal or spatial changes of fundamental constants in the early universe. An important systematic that has never before been quantified concerns model…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-25 Chung-Chi Lee , John K. Webb , Dinko Milaković , Robert F. Carswell

This paper examines the use of Monte Carlo simulations to understand statistical concepts in A/B testing and Randomized Controlled Trials (RCTs). We discuss the applicability of simulations in understanding false positive rates and estimate…

Applications · Statistics 2024-11-12 Márton Trencséni

By measuring the fundamental constants in astrophysical objects one can test basic physical principles as space-time invariance of physical laws along with probing the applicability limits of the standard model of particle physics. The…

Instrumentation and Methods for Astrophysics · Physics 2016-03-07 S. A. Levshakov

We investigate the use of different variational principles in quantum Monte Carlo, namely energy and variance minimization, prompted by the interest in the robust and accurate estimate of electronic excited states. For two prototypical,…

Chemical Physics · Physics 2021-11-19 Alice Cuzzocrea , Anthony Scemama , Wim J. Briels , Saverio Moroni , Claudia Filippi

Most applications of Bayesian Inference for parameter estimation and model selection in astrophysics involve the use of Monte Carlo techniques such as Markov Chain Monte Carlo (MCMC) and nested sampling. However, these techniques are time…

Instrumentation and Methods for Astrophysics · Physics 2022-01-26 Geetakrishnasai Gunapati , Anirudh Jain , P. K. Srijith , Shantanu Desai

One of the topical problems of contemporary physics is a possible variability of the fundamental constants. Here we consider possible variability of two dimensionless constants which are most important for calculation of atomic and…

Atomic Physics · Physics 2016-09-08 D. A. Varshalovich , A. Y. Potekhin , A. V. Ivanchik

Experimentation platforms in industry must often deal with customer trust issues. Platforms must prove the validity of their claims as well as catch issues that arise. As a central quantity estimated by experimentation platforms, the…

Methodology · Statistics 2025-11-21 Kedar Karhadkar , Jack Klys , Daniel Ting , Artem Vorozhtsov , Houssam Nassif

We devise an optimal method to measure the temporal power spectrum of the lensing and intrinsic fluctuations of multiply-imaged strongly lensed quasar light curves, along with the associated time delays. The method is based on a Monte-Carlo…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-18 Mansour Karami , Niayesh Afshordi , Jesús Zavala

The combination of continuum Many-Body Quantum physics and Monte Carlo methods provide a powerful and well established approach to first principles calculations for large systems. Replacing the exact solution of the problem with a…

Computational Physics · Physics 2009-10-01 J. R. Trail

Variability in gravitationally lensed quasars can be due to intrinsic fluctuations of the quasar or due to ``microlensing'' by compact objects along the line of sight. If disentangled from each other, microlens-induced variability can be…

Astrophysics · Physics 2007-05-23 Joachim Wambsganss

Categorical variables are of uttermost importance in biomedical research. When two of them are considered, it is often the case that one wants to test whether or not they are statistically dependent. We show weaknesses of classical methods…

We use numerical simulations to test a broad range of plausible observational strategies designed to measure the time delay between the images of gravitationally lensed quasars. Artificial quasar light curves are created along with…

Astrophysics · Physics 2009-11-10 A. Eigenbrod , F. Courbin , C. Vuissoz , G. Meylan , P. Saha , S. Dye

Cosmological weak lensing by the large scale structure of the Universe, cosmic shear, is coming of age as a powerful probe of the parameters describing the cosmological model and matter power spectrum. It complements CMB studies, by…

Astrophysics · Physics 2009-11-10 Patrick Simon , Lindsay J. King , Peter Schneider

The standard technique for measurement of random uncertainties of star formation histories (SFHs) is the bootstrap Monte Carlo, in which the color-magnitude diagram (CMD) is repeatedly resampled. The variation in SFHs measured from the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-16 Andrew E. Dolphin

Gravitational microlensing is a powerful tool to probe the inner structure of strongly lensed quasars and to constrain parameters of the stellar mass function of lens galaxies. This is done by analysing microlensing light curves between the…

Astrophysics of Galaxies · Physics 2022-03-14 E. Paic , G. Vernardos , D. Sluse , M. Millon , F. Courbin , J. H. Chan , V. Bonvin

High precision asteroseismic data provide a unique opportunity to test input microphysics such as stellar opacities, chemical composition or equation of state. These tests are possible because pulsational frequencies as well as amplitudes…

Solar and Stellar Astrophysics · Physics 2015-06-18 Przemysław Walczak , Jadwiga Daszyńska-Daszkiewicz

This paper presents an investigation into the gravitational microlensing of quasars by stars and stellar remnants in the Milky Way. We present predictions for the all-sky microlensing optical depth, time-scale distributions and event rates…

Astrophysics of Galaxies · Physics 2015-05-18 Jian Wang , Martin C. Smith