Cosmological Perturbation Theory in $f(Q,T)$ Gravity

Abstract

We developed the cosmological linear theory of perturbations for $f(Q,T)$ gravity, which is an extension of symmetric teleparallel gravity, with $Q$ the non-metricity and $T$ the trace of the stress-energy tensor. By considering an ansatz of $f(Q,T)=f_1(Q)+f_2(T)$, which has been broadly studied in the literature and the coincident gauge where the connection vanishes, we got equations consistent with $f(Q)$ gravity when $f_T=0$. In the case of the tensor perturbations, the propagation of gravitational waves was found to be identical to $f(Q)$, as expected. For scalar perturbations, outside the limit $f_T=0$, we got that the coupling between $Q$ and $T$ in the Lagrangian produces a coupling between the perturbation of the density and the pressure. The presence of $T$ in the Lagrangian breaks the equation of the conservation of energy, which in turn breaks the standard ${\rho }^{\prime }+3\mathcal{H}(\rho +p)=0$ relation. We also derived a coupled system of differential equations between $\delta$, the density contrast and $v$ in the $\mathcal{H}<<k$ limit and with negligible time derivative of the scalar perturbation potentials, which will be useful in future studies to see whether this class of theories constitute a good alternative to dark matter. These results might also enable to test $f(Q,T)$ gravity with CMB and standard siren data that will help to determine if these models can reduce the Hubble constant tension and if they can constitute an alternative to the $\Lambda$CDM model.

20 pages. Accepted by JCAP

References in corpus (25)

• f(R,T) gravity
• Large Magellanic Cloud Cepheid Standards Provide a 1% Foundation for the Determination of the Hubble Constant and Stronger Evidence for Physics Beyond LambdaCDM
• The teleparallel equivalent of general relativity
• Teleparallel Gravity: From Theory to Cosmology
• The Cosmic Linear Anisotropy Solving System (CLASS) I: Overview
• On the Hubble constant tension in the SNe Ia Pantheon sample
• Running Hubble Tension and a H0 Diagnostic
• $f(Q,T)$ gravity models with observational constraints
• Matter Bounce Scenario and the Dynamical aspects in f(Q,T) Gravity
• Constraining $f(Q,T)$ gravity from energy conditions
• Cosmology Intertwined I: Perspectives for the Next Decade
• Energy conditions in $f(Q,T)$ gravity
• Fitting $f(Q,T)$ gravity models with a $\Lambda$CDM limit using H(z) and Pantheon data
• Constraining effective equation of state in $f(Q,T)$ gravity
• FRW Cosmology in $f(Q,T)$ Gravity
• Model parameters in the context of late time cosmic acceleration in $f(Q,T)$ gravity
• Viscous cosmology in the Weyl-type $f(Q,T)$ gravity
• Power-law cosmology in Weyl-type $f(Q,T)$ gravity
• Variational Principles in Teleparallel Gravity Theories
• Bulk viscous matter and the cosmic acceleration of the universe in $f(Q,T)$ gravity
• Transit cosmological models with observational constraints in f(Q, T) gravity
• The Atacama Cosmology Telescope: Summary of DR4 and DR5 Data Products and Data Access
• BBN Constraints on $f(Q,T)$ Gravity
• How to calculate the CMB spectrum
• A new perspective on cosmology through Supernovae Ia and Gamma Ray Bursts

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