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Related papers: Null tests with Gaussian Process

200 papers

The $O_k$ null test can not only assess whether the cosmic curvature is zero, therefore if true reducing degeneracies between cosmic curvature and other cosmological parameters, but also provide a model-independent check of compatibility…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-27 Yungui Gong , Qing Gao , Xuchen Lu , Zhu Yi

The DESI DR2 BAO data, in combination with CMB and different SNIa datasets, exclude the flat $\Lambda$CDM model at more than 2.5$\sigma$ when analyzed through the $w_0w_a$CDM parametrization for evolving dark energy. This simple…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-11 Bikash R. Dinda , Roy Maartens , Shun Saito , Chris Clarkson

We investigate the null tests of cosmic accelerated expansion by using the Baryon Acoustic Oscillation (BAO) data measured by the Dark Energy Spectroscopic Instrument (DESI) and reconstruct the dimensionless Hubble parameter $E(z)$ from the…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-23 Xuchen Lu , Shengqing Gao , Yungui Gong

We introduce a new diagnostic for the null tests of dynamical dark energy alongside two other combined equivalent diagnostics. These diagnostics are useful, especially when we include anisotropic baryon acoustic oscillation (BAO) data in an…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-05 Bikash R. Dinda

In this analysis we apply a model-independent framework to test the flat $\Lambda$CDM cosmology using simulated SNIa data from the upcoming Legacy Survey of Space and Time (LSST) and combined with simulated Dark Energy Spectroscopic…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-19 Benjamin L'Huillier , Ayan Mitra , Arman Shafieloo , Ryan E. Keeley , Hanwool Koo

We present a calibration-free consistency test of spatially flat $\Lambda$CDM based on baryon acoustic oscillation (BAO) distance measurements. The method forms ratios of BAO distances including the Hubble distance, the comoving angular…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-26 Xing-Han A. Zhao , Zheng Cai

Baryon Acoustic Oscillations (BAO) provide an important standard ruler which can be used to probe the recent expansion history of our universe. We show how a simple extension of the Om diagnostic, which we call Om3, can combine standard…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-07 Arman Shafieloo , Varun Sahni , Alexei A. Starobinsky

We use the Om statistic and the Genetic Algorithms (GA) in order to derive a null test on the spatially flat cosmological constant model $\Lambda$CDM. This is done in two steps: first, we apply the GA to the Constitution SNIa data in order…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-14 Savvas Nesseris , Arman Shafieloo

Baryon acoustic oscillation (BAO) analyses usually report the anisotropic shift parameters $\alpha_\perp(z)$ and $\alpha_\parallel(z)$ relative to a fiducial cosmology, and these quantities are primarily used for cosmological parameter…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-20 Domenico Sapone , Savvas Nesseris

Since there is no known symmetry in Nature that prevents a non-minimal coupling between the dark energy (DE) and cold dark matter (CDM) components, such a possibility constitutes an alternative to standard cosmology, with its theoretical…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-21 Rodrigo von Marttens , Valerio Marra , Luciano Casarini , J. E. Gonzalez , Jailson Alcaniz

This article questions the common assumption of cold dark matter (DM) by exploring the possibility of a non-zero equation of state (EoS) without relying on any parametric approach. In standard cosmological analyses, DM is typically modeled…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-01 Mazaharul Abedin , Luis A. Escamilla , Supriya Pan , Eleonora Di Valentino , Weiqiang Yang

In this work, we implement Gaussian process regression to reconstruct the expansion history of the universe in a model-agnostic manner, using the Pantheon-Plus SN-Ia compilation in combination with two different BAO measurements (SDSS-IV…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-02 Purba Mukherjee , Anjan Ananda Sen

We propose a new and highly model-independent test of cosmic acceleration by comparing observations of the baryon acoustic oscillation (BAO) scale at low and intermediate redshifts: we derive a new inequality relating BAO observables at two…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-19 Will Sutherland

In this work, we present comprehensive observational constraints on the time-varying vacuum $\Lambda(t)$CDM cosmology using the latest baryon acoustic oscillation (BAO) data from Dark Energy Spectroscopic Instrument (DESI) Data Release 2…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-05 Olga Avsajanishvili

We develop methods for investigating baryon acoustic oscillation (BAO) features in cosmological models with non-trivial (but slowly varying) averaged spatial curvature: models that are not necessarily flat, close to flat, nor with constant…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-06 Asta Heinesen , Chris Blake , Yong-Zhuang Li , David L. Wiltshire

We nonparametrically reconstruct the late-time expansion history in light of the latest Baryon Acoustic Oscillation (BAO) measurements from DESI combined with various Type Ia Supernovae (SNeIa) catalogs, using interpolation through…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-12 Jun-Qian Jiang , Davide Pedrotti , Simony Santos da Costa , Sunny Vagnozzi

We analyse some open debates in cosmology in light of the most updated quasar (QSO) sample, covering a wide redshift range up to $z\sim7.5$, combined with type Ia supernovae (SNe) and baryon acoustic oscillations (BAO). Indeed, extending…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-04 G. Bargiacchi , M. Benetti , S. Capozziello , E. Lusso , G. Risaliti , M. Signorini

The cosmic microwave background (CMB) and baryon acoustic oscillations (BAO) are two of the most robust observations in cosmology. The recent BAO measurements from the DESI collaboration have presented, for the first time, inconsistency…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-13 Gen Ye , Matteo Martinelli , Bin Hu , Alessandra Silvestri

Recent measurements of Baryon Acoustic Oscillations (BAO) from the Dark Energy Spectroscopic Survey (DESI DR2), combined with data from the cosmic microwave background (CMB) and Type Ia supernovae (SNe), challenge the $\Lambda$-Cold Dark…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-16 Agripino Sousa-Neto , Carlos Bengaly , Javier E. Gonzalez , Jailson Alcaniz

Combined measurements of Baryon Acoustic Oscillations (BAO) from the Dark Energy Spectroscopic Survey (DESI), the Cosmic Microwave Background (CMB) and Type Ia Supernovae (SN Ia), have recently challenged the $\Lambda$-Cold Dark Matter…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-10 Rayff de Souza , Agripino Sousa-Neto , Javier E. González , Jailson Alcaniz
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