<p>We examine an isotropic cosmological framework in which both the gravitational constant <InlineEquation ID="IEq2"> <EquationSource Format="MATHML"><math> <mi>G</mi> </math></EquationSource> <EquationSource Format="TEX">$G$</EquationSource> </InlineEquation> and the cosmological term <InlineEquation ID="IEq3"> <EquationSource Format="MATHML"><math> <mi mathvariant="normal">Λ</mi> </math></EquationSource> <EquationSource Format="TEX">$\Lambda $</EquationSource> </InlineEquation> evolve with cosmic time. The varying dark energy explains the different features of the universe in the considered framework. For the power-law parametrization for <InlineEquation ID="IEq4"> <EquationSource Format="MATHML"><math> <mi>G</mi> </math></EquationSource> <EquationSource Format="TEX">$G$</EquationSource> </InlineEquation>, we solve the corresponding cosmological equations to obtain the expansion rate. In order to determine the robust observational constraints on model parameters, we employ the latest DESI DR2 BAO measurements with the Cosmic Chronometers (CC) and Pantheon+SH0ES (PPS) data. The likelihood is constructed using the Markov chain Monte Carlo (MCMC) analysis and compared for the estimated parameters. The evolution of cosmological parameters such as the Hubble parameter, deceleration parameter, effective equation of state parameter are analyzed to investigate the cosmic evolution and dynamical behavior of the model. The late-time accelerating scenario of model has also been tested for bounds on <InlineEquation ID="IEq5"> <EquationSource Format="MATHML"><math> <mover accent="true"> <mi>G</mi> <mo>˙</mo> </mover> <mo stretchy="false">/</mo> <mi>G</mi> </math></EquationSource> <EquationSource Format="TEX">$\dot{G}/G$</EquationSource> </InlineEquation> and information criterion to describe its performance with <InlineEquation ID="IEq6"> <EquationSource Format="MATHML"><math> <mi mathvariant="normal">Λ</mi> </math></EquationSource> <EquationSource Format="TEX">$\Lambda $</EquationSource> </InlineEquation>CDM model.</p>

Observational constraints on varying-$(G,\Lambda )$ cosmology with DESI DR2

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发表日期：

2026年4月24日

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S. Mandal,
A. Singh,
R. Chaubey

摘要

We examine an isotropic cosmological framework in which both the gravitational constant $G$ $G$ and the cosmological term $Λ$ $\Lambda $ evolve with cosmic time. The varying dark energy explains the different features of the universe in the considered framework. For the power-law parametrization for $G$ $G$ , we solve the corresponding cosmological equations to obtain the expansion rate. In order to determine the robust observational constraints on model parameters, we employ the latest DESI DR2 BAO measurements with the Cosmic Chronometers (CC) and Pantheon+SH0ES (PPS) data. The likelihood is constructed using the Markov chain Monte Carlo (MCMC) analysis and compared for the estimated parameters. The evolution of cosmological parameters such as the Hubble parameter, deceleration parameter, effective equation of state parameter are analyzed to investigate the cosmic evolution and dynamical behavior of the model. The late-time accelerating scenario of model has also been tested for bounds on $\dot{G} / G$ $\dot{G}/G$ and information criterion to describe its performance with $Λ$ $\Lambda $ CDM model.

Observational constraints on varying-\((G,\Lambda )\) cosmology with DESI DR2

摘要