Cosmological implications and causality in $f(R,L_m,T)$ gravity theory with observational constraints

Abstract

In the generalized matter-geometry coupling theory, we investigate the physical characteristics and causality of some new cosmological models for a flat, homogeneous, and isotropic spacetime filled with stiff, radiation, dust, and curvature fluid sources. We obtain a particular cosmological model corresponding to each source fluid, called Models I, II, III, and IV, respectively. We make observational constraints on each model using the joint analysis of $31$ Cosmic Chronometer (CC) Hubble dataset and $1701$ Pantheon+SH0ES datasets to estimate the current values of model parameters. Using these statistical results, we have analyzed the information criteria, effective EoS parameter, causality of the models, and viability of this generalized gravity theory. Subsequently, we investigate the effective equation of state and deceleration parameter for each model. We found that all models in the late-time universe exhibit transit-phase acceleration, and Models I and II show both the early as well as late-time accelerating phase of the expanding universe. We found the current values of the deceleration parameter in the range $-0.8857\le q_0\le -0.4279$ with transition redshift $0.4867\le z_t\le 0.839$ and the effective EoS parameter in the range $-0.9238\le {\omega }_{eff}\le -0.6186$. We analyzed the square sound speed condition $c_s^2\le c^2$ for each model.

23 pages, 8 figures

References in corpus (26)

• Dynamics of dark energy
• Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models
• f(R,T) gravity
• A Comprehensive Measurement of the Local Value of the Hubble Constant with 1 km/s/Mpc Uncertainty from the Hubble Space Telescope and the SH0ES Team
• The Pantheon+ Analysis: Cosmological Constraints
• Spectra and Light Curves of Six Type Ia Supernovae at 0.511 < z < 1.12 and the Union2 Compilation
• Extra force in $f(R)$ modified theories of gravity
• The Pantheon+ Analysis: The Full Dataset and Light-Curve Release
• Cosmic Distances Calibrated to 1% Precision with Gaia EDR3 Parallaxes and Hubble Space Telescope Photometry of 75 Milky Way Cepheids Confirm Tension with LambdaCDM
• f(R,L_m) gravity
• Nonminimal coupling of perfect fluids to curvature
• Modified gravity with arbitrary coupling between matter and geometry
• Thermodynamic interpretation of the generalized gravity models with geometry - matter coupling
• Cosmographic bounds on the cosmological deceleration-acceleration transition redshift in $f(\mathcal{R})$ gravity
• Unifying of Inflation with Early and Late Dark Energy Epochs in Axion $F(R)$ Gravity
• Causality and the speed of sound
• Generalizing the coupling between geometry and matter: $f(R,L_m,T)$ gravity
• On the homogeneity of SnIa absolute magnitude in the Pantheon+ sample
• Observational constraints on Myrzakulov gravity
• Cosmology in scalar-tensor $f(R,T)$ gravity
• Constraints on the transition redshift from the calibrated Gamma-ray Burst $E_{\mathrm{p}}$-$E_{\mathrm{iso}}$ correlation
• Modeling Transit Dark Energy in $f(R,L_m)$-gravity
• A model independent approach to the study of $f(R)$ cosmologies with expansion histories close to $\Lambda$CDM
• Energy conditions in the $f(R,L,T)$ theory of gravity
• Dark Energy Nature in Logarithmic $f(R,T)$ Cosmology
• Constrained transit cosmological models in $f(R,L_m,T)$-gravity