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Related papers: Observational Insights on DBI K-essence Models Usi…

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In this work, we investigate the Dirac--Born--Infeld (DBI) scalar field model with and without the inclusion of the chameleon mechanism in light of the latest cosmological observations. We constrain the model using data from Pantheon Plus,…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-28 Burin Gumjudpai , Nandan Roy , John Ward

We present a simulation-based cosmological analysis using a combination of Gaussian and non-Gaussian statistics of the weak lensing mass (convergence) maps from the first three years (Y3) of the Dark Energy Survey (DES). We implement: 1)…

We assess dataset agreement and late-time predictive adequacy in $\Lambda$CDM and its sign-switching extension, $\Lambda_{\rm s}$CDM, using a suite of Gaussian and exact non-Gaussian consistency diagnostics. Both models are constrained with…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-11 Sehjal Khandelwal , Abraão J. S. Capistrano , Suresh Kumar

We investigate several phenomenological dark energy parameterizations using a joint analysis of late-time cosmological observations, including cosmic-chromatometer measurements of the Hubble parameter, DESI DR2 baryon acoustic oscillation…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-08 Chanchal Kumari , Dinesh Kumar

We investigate the cosmological observational test of the extended quintessence model, i.e. a scalar-tensor gravity model with a scalar field potential serving as dark energy, by using the Planck 2018 cosmic microwave background (CMB) data,…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 Gong Cheng , Fengquan Wu , Xuelei Chen

We perform a comprehensive observational test of a canonical quintessence model driven by an exponential potential, motivated by its emergence in higher-dimensional theories, string-inspired scenarios, and modified gravity. Using a Markov…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-07 Sanjeeda Sultana , Surajit Chattopadhyay

We perform for the first time a dynamical system analysis of both the background and perturbation equations, of $\Lambda$CDM cosmology and quintessence scenario with an exponential potential. In the former case the perturbations do not…

General Relativity and Quantum Cosmology · Physics 2019-08-21 Spyros Basilakos , Genly Leon , G. Papagiannopoulos , Emmanuel N. Saridakis

There is mounting evidence from multiple cosmological probes that dark energy may be dynamical, with an equation of state that evolves over cosmic time. While this evidence is typically quantified using the Chevallier-Polarski-Linder (CPL)…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-02 Daniel A. Kessler , Luis A. Escamilla , Supriya Pan , Eleonora Di Valentino

The standard approach to inference from cosmic large-scale structure data employs summary statistics that are compared to analytic models in a Gaussian likelihood with pre-computed covariance. To overcome the idealising assumptions about…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-24 Kiyam Lin , Maximilian von Wietersheim-Kramsta , Benjamin Joachimi , Stephen Feeney

This paper examines interacting dark energy models within the Chevallier-Polarski-Linder (CPL) parametrization, emphasizing both theoretical structure and observational viability. Two commonly adopted interaction terms are considered: $Q =…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-28 Gerald Neumann , Nelson Videla , Dorian Araya

There are several methods for model selection in cosmology which have at least two major goals, that of finding the correct model or predicting well. In this work we discuss through a study of well-known model selection methods like Akaike…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-23 Mehdi Rezaei , Mohammad Malekjani

We study the integrated Sachs-Wolfe (ISW) effect using a model-independent parameterization of the dark energy equation of state. Cosmic variance severely restricts the class of models distinguishable from Lambda-CDM. In particular if the…

Astrophysics · Physics 2009-11-07 P. S. Corasaniti , B. A. Bassett , C. Ungarelli , E. J. Copeland

The DESI collaboration have recently analyzed their first year of data, finding a preference for thawing dark energy scenarios when using parameterized equations of state for dark energy. We investigate whether this preference persists when…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-30 Omar F. Ramadan , Jeremy Sakstein , David Rubin

In this work, we explore the evolution of the dark energy equation of state {\omega} by using Chevalliear-PolarskiLinder (CPL) parametrization and the binned parametrizations. For binned parametrizations, we adopt three methods to choose…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-05 Xiaolin Luo , Shuang Wang , Sixiang Wen

The new Dark Energy Spectroscopic Instrument (DESI) DR2 results have strengthened the possibility that dark energy is dynamical, i.e., it has evolved over the history of the Universe. One simple, but theoretically well motivated and widely…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-14 Yashar Akrami , George Alestas , Savvas Nesseris

We carry out a comparative analysis of the standard $\Lambda$CDM cosmological model and the alternative $R_h=ct$ framework using recent observational data from cosmic chronometers (CC), Type Ia supernova, and baryon acoustic oscillations.…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-26 Amritansh Mehrotra , S. K. J. Pacif , A. F. Santos

Recent baryon acoustic oscillation (BAO) measurements from the Dark Energy Spectroscopic Instrument (DESI) collaboration have renewed interest in dynamical dark energy models, particularly those that cross the "phantom divide" ($w_{\rm DE}…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-24 Samuel Goldstein , Marco Celoria , Fabian Schmidt

The $\Lambda$ cold dark matter ($\Lambda\textrm{CDM}$) model is currently known as the simplest cosmology model that best describes observations with minimal number of parameters. Here we introduce a cosmology model that is preferred over…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-05 Chan-Gyung Park

We study a class of Unified Dark Matter (UDM) models based on generalized K-essence, where a single scalar field with non-canonical kinetic terms accounts for dark radiation, dark matter, and dark energy. Starting from the purely kinetic…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-26 Eladio Moreno , Josue De-Santiago

Observations of Type Ia supernovae (\sne), which probe the late Universe, together with baryon acoustic oscillations (BAO) and the cosmic microwave background (CMB), which probe the intermediate and early epochs, provide complementary…