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Related papers: Expected redshift drift for tilted observers

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We study a parametrization of the deceleration parameter in a tilted universe, namely a cosmological model equipped with two families of observers. The first family follows the smooth Hubble flow, while the second are the real observers…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-01 Kerkyra Asvesta , Lavrentios Kazantzidis , Leandros Perivolaropoulos , Christos G. Tsagas

A key observational prediction of Einstein's Equivalence Principle is that light undergoes redshift when it escapes from a gravitational field. Although astrophysics provides a wide variety of physical conditions in which this redshift…

Astrophysics of Galaxies · Physics 2022-04-20 Carlos M. Gutiérrez , Nataliya Ramos-Chernenko

The interpretation of cosmological observations relies on a notion of an average Universe, which is usually considered as the homogeneous and isotropic Friedmann-Lema\^itre-Robertson-Walker (FLRW) model. However, inhomogeneities may…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-24 Michel-Andrès Breton , Pierre Fleury

We study the estimation of time-homogeneous drift functions in multivariate stochastic differential equations with known diffusion coefficient, from multiple trajectories observed at high frequency over a fixed time horizon. We formulate…

Machine Learning · Statistics 2026-02-23 Marcos Tapia Costa , Nikolas Kantas , George Deligiannidis

We carry out a covariant calculation of the measurable relativistic effects in an orbiting gyroscope experiment. The experiment, currently known as Gravity Probe B, compares the spin directions of an array of spinning gyroscopes with the…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Clifford M. Will

We derive a redshift drift formula within the framework of varying speed of light (VSL) theory using the specific ansatz for the variability of $c(t) = c_0 a^n(t)$. We show that negative values of the parameter $n$, which correspond to…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-26 Adam Balcerzak , Mariusz P. Dabrowski

The success of precision cosmology depends not only on accurate observations, but also on the theoretical model - which must be understood to at least the same level of precision. Subtle relativistic effects can lead to biased measurements…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Chris Clarkson , Obinna Umeh , Roy Maartens , Ruth Durrer

Reinforcement learning (RL) agents typically assume stationary environment dynamics. Yet in real-world applications such as healthcare, robotics, and finance, transition probabilities or reward functions may evolve, leading to model drift.…

Machine Learning · Computer Science 2025-09-16 Chang-Hwan Lee , Alexander Shim

The notion of drift refers to the phenomenon that the distribution, which is underlying the observed data, changes over time. Albeit many attempts were made to deal with drift, formal notions of drift are application-dependent and…

Machine Learning · Computer Science 2019-12-05 Fabian Hinder , André Artelt , Barbara Hammer

An adaptive-gain super-twisting sliding mode observer is proposed for fault reconstruction in electro-hydraulic servo systems (EHSS) receiving bounded perturbations with unknown bounds. The objective is to address challenging problems in…

Systems and Control · Electrical Eng. & Systems 2023-10-27 Rayan Bahrami , Mahyar Naraghi , Mohammad Zareinejad

In recent years the possibility of measuring the temporal change of radial and transverse position of sources in the sky in real time have become conceivable thanks to the thoroughly improved technique applied to new astrometric and…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-26 Claudia Quercellini , Luca Amendola , Amedeo Balbi , Paolo Cabella , Miguel Quartin

In Continual Learning (CL) contexts, concept drift typically refers to the analysis of changes in data distribution. A drift in the input data can have negative consequences on a learning predictor and the system's stability. The majority…

Machine Learning · Computer Science 2024-10-23 Sebastian Basterrech

The redshift dependence of the cosmic microwave background temperature, $T(z)=T_0(1+z)$, is a key prediction of standard cosmology, but this relation is violated in many extensions thereof. Current astrophysical facilities can probe it in…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-09 C. J. A. P. Martins , A. M. M. Vieira

Exact inhomogeneous solutions of Einstein's equations have been used in the literature to build models reproducing the cosmological data without dark energy. However, owing to the degrees of freedom pertaining to these models, it is…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-29 Priti Mishra , Marie-Noëlle Célérier , Tejinder P. Singh

We derive consistency and asymptotic normality results for quasi-maximum likelihood methods for drift parameters of ergodic stochastic processes observed in discrete time in an underlying continuous-time setting. The special feature of our…

Statistics Theory · Mathematics 2021-09-20 Teppei Ogihara , Mitja Stadje

We consider some aspects of the perturbation to the luminosity distance $d(z)$ that are of relevance for SN1a cosmology and for future peculiar velocity surveys at non-negligible redshifts. 1) Previous work has shown that the correction to…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Nick Kaiser , Michael J. Hudson

We derive exact expressions for the relativistic redshift between an Earth-bound observer, that is meant to model a standard clock on the Earth's surface, and various (geodesic) observers in the Schwarzschild spacetime. We assume that the…

General Relativity and Quantum Cosmology · Physics 2017-11-06 Dennis Philipp , Eva Hackmann , Claus Laemmerzahl

We investigate the potential and accuracy of clustering-based redshift estimation using the method proposed by M\'enard et al. (2013). This technique enables the inference of redshift distributions from measurements of the spatial…

Astrophysics of Galaxies · Physics 2015-06-22 Mubdi Rahman , Brice Ménard , Ryan Scranton , Samuel J. Schmidt , Christopher B. Morrison

The redshift of all cosmological sources drifts by a systematic velocity of order a few m/s over a century due to the deceleration of the Universe. The specific functional dependence of the predicted velocity shift on the source redshift…

Astrophysics · Physics 2011-02-11 Abraham Loeb

Recent calculations using non-linear relativistic cosmological perturbation theory show biases in the mean luminosity distance and distance modulus at low redshift. We show that these effects may be understood very simply as a…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-30 Nick Kaiser , Michael J. Hudson