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arXiv · 2510.03042

Scalar-Tensor Symmetric Teleparallel Gravity: Reconstruct the Cosmological History with a Steep Potential

Ghulam Murtaza·Avik De·Andronikos Paliathanasis
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Abstract

Within the framework of scalar-non-metricity gravity, we introduce a steep potential together with a power-law coupling function and investigate whether the acceleration phases of the universe can be consistently described by this model. In the symmetric teleparallel formulation, and under a Friedmann--Lema\^itre--Robertson--Walker background, three distinct branches of the connection arise, leading to three different cosmological scenarios. We perform a detailed dynamical analysis of these models by examining the phase space and determining the asymptotic cosmological solutions. The analysis reveals a rich hierarchy of critical points, including matter-dominated epochs, kinetic-dominated stiff-fluid regimes, and steep potential-dominated de Sitter solutions, along with asymptotic trajectories that approach Big Crunch or Big Rip singularities, as well as transient, unstable matter-dominated eras. The stability of the steep potential-dominated de Sitter points is further studied using Center Manifold Theory, showing that, under specific parametric conditions, the model can provide a unified description of both the early and late-time acceleration phases of the universe.

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Ghulam Murtaza, Avik De, Andronikos Paliathanasis. 2025-10-03. Scalar-Tensor Symmetric Teleparallel Gravity: Reconstruct the Cosmological History with a Steep Potential. https://doi.org/10.1088/1475-7516%2F2026%2F09%2F057

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