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Related papers: Cosmological Model Independent Time Delay Method

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In this work, we have considered a model independent approach to study the nature of the late time cosmic acceleration. We have used the Pade approximation to parametrize the comoving distance. Consequently, from this comoving distance, we…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-09 Bikash R. Dinda

We present a model-independent method of reconstructing scale factor against lookback time from the Observational Hubble parameter Data (OHD). The reconstruction method is independent of dynamical models and is only based on the…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-30 Jian-Chen Zhang , Jing Zheng , Tong-Jie Zhang

In this work, we investigate a cosmological scenario with a time-dependent cosmological constant $\Lambda$(t) within the spatially flat Friedmann-Lema\^itre-Robertson-Walker (FLRW) framework. Here we study a power-law $\Lambda(t)$CDM model…

General Relativity and Quantum Cosmology · Physics 2025-10-28 Archana Dixit , Manish Yadav , Anirudh Pradhan , M. S. Barak

This work proposes an interval observer design for nonlinear discrete-time systems based on the Kazantzis-Kravaris/Luenberger (KKL) paradigm. Our design extends to generic nonlinear systems without any assumption on the structure of its…

Systems and Control · Electrical Eng. & Systems 2024-04-30 Thach Ngoc Dinh , Gia Quoc Bao Tran

Verification of temporal logic properties plays a crucial role in proving the desired behaviors of hybrid systems. In this paper, we propose an interval method for verifying the properties described by a bounded linear temporal logic. We…

Logic in Computer Science · Computer Science 2015-07-15 Daisuke Ishii , Naoki Yonezaki , Alexandre Goldsztejn

A time-dependent phenomenological model of $\Lambda$, viz. $\dot \Lambda\sim H^3$ is selected to investigate the $\Lambda$-CDM cosmology. Time-dependent form of the equation of state parameter $\omega$ is derived and it has been possible to…

General Relativity and Quantum Cosmology · Physics 2008-11-26 U. Mukhopadhyay , Saibal Ray , S. B. Dutta Choudhury

We derive the free energy of a Lorentz invariance violating (LIV) O(2) model, for which a non-vanishing commutator among it's momenta is supposed. Then we investigate the possible implications of such a matter field on the time evolution of…

High Energy Physics - Theory · Physics 2012-10-10 A. Jahan

We pursue a program to confront observations with inhomogeneous extensions of the FLRW metric. The main idea is to test the Copernican principle rather than assuming it a priori. We consider the $\Lambda$CDM model endowed with a spherical…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-23 David Camarena , Valerio Marra , Ziad Sakr , Chris Clarkson

Imitation learning from demonstrations usually suffers from the confounding effects of unmeasured variables (i.e., unmeasured confounders) on the states and actions. If ignoring them, a biased estimation of the policy would be entailed. To…

Machine Learning · Computer Science 2025-07-24 Yan Zeng , Shenglan Nie , Feng Xie , Libo Huang , Peng Wu , Zhi Geng

We investigate cosmological constraints on K-mouflage models of modified gravity. We consider two scenarios: one where the background evolution is free to deviate from $\Lambda$CDM (K-mouflage) and another one which reproduces a…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-29 Giampaolo Benevento , Marco Raveri , Andrei Lazanu , Nicola Bartolo , Michele Liguori , Philippe Brax , Patrick Valageas

Measuring time delays between the multiple images of gravitationally lensed quasars is now recognized as a competitive way to constrain the cosmological parameters, and it is complementary with other cosmological probes. This requires long…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-21 M. Tewes , F. Courbin , G. Meylan

The cosmic curvature $\Omega_{K}$ is an important parameter related to the inflationary cosmology and the ultimate fate of the universe. In this work, we adopt the non-CMB observations to constrain $\Omega_{K}$ in the $\Lambda$CDM model and…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-12 Peng-Ju Wu , Xin Zhang

The absence of guidance from fundamental physics about the mechanism behind cosmic acceleration has given rise to a number of alternative cosmological scenarios. These are based either on modifications of general relativistic gravitation…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 M. A. Dantas , J. S. Alcaniz , D. Mania , Bharat Ratra

A measurement of the redshift drift constitutes a model-independent probe of fundamental cosmology. Several approaches are being considered to make the necessary observations, using (i) the Extremely Large Telescope (ELT), (ii) the Cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-13 Fulvio Melia

Cosmological models assuming the scale invariance of the macroscopic empty space show an accelerated expansion, without calling for some unknown particles. Several comparisons between models and observations (tests on distances, m-z…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-04 Andre Maeder

Conditional local independence is an asymmetric independence relation among continuous time stochastic processes. It describes whether the evolution of one process is directly influenced by another process given the histories of additional…

Statistics Theory · Mathematics 2024-02-26 Alexander Mangulad Christgau , Lasse Petersen , Niels Richard Hansen

In this study, we investigate signature flips within the framework of cosmological models featuring a time-varying vacuum energy term $\Lambda(t)$. Specifically, we consider the power-law form of $\Lambda=\alpha H^n$, where $\alpha$ and $n$…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-11 Yerlan Myrzakulov , M. Koussour , M. Karimov , J. Rayimbaev

We present a new solution to the cosmological constant (CC) and coincidence problems in which the observed value of the CC, $\Lambda$, is linked to other observable properties of the universe. This is achieved by promoting the CC from a…

General Relativity and Quantum Cosmology · Physics 2015-03-17 Douglas J. Shaw , John D. Barrow

We introduce a time-delay function in bulk viscosity cosmology. Even for bulk viscosity functions where closed-form solutions are known, because of the time-delay term the exact solutions are lost. Therefore in order to study the…

General Relativity and Quantum Cosmology · Physics 2022-11-23 Andronikos Paliathanasis

Recently Rizzo studied the Lorentz Invariance Violation (LIV) in a brane scenario with one extra dimension where he found a non-zero mass for the four-dimensional graviton. This leads to the conclusion that five-dimensional models with LIV…

High Energy Physics - Theory · Physics 2012-12-21 Victor Santos , C. A. S. Almeida