Exact Solutions for a Teleparallel Cosmological Model with Vector Field via Noether Symmetry
Exact Solutions for a Teleparallel Cosmological Model with Vector Field via Noether Symmetry
We study a cosmological model in the framework of teleparallel gravity, where a vector field $A_μ$ is non-minimally coupled to the torsion scalar $T$ in a flat Friedmann-Robertson-Walker (FRW) universe. Using the Noether symmetry approach, we identify specific forms for the coupling function $g(ξ)$ and the potential $V(ξ) = V_0 ξ^n$, with $ξ\equiv A_μA^μ$. The method allows us to find exact analytical solutions for the scale factor $a(t)$ and the scalar function $ξ(t)$. General solutions for arbitrary values of $n$ are derived, but special cases such as $n = 1$ and $n = 3$ are studied separately due to their distinct behavior. For $n = 1$, the model describes a transition from decelerated to accelerated expansion, and depending on the value of the model parameter, a transition to a phantom phase is also possible, which is consistent with phantom dark energy. For the special case $n=3$, this model first experiences a deceleration phase and then enters a stable accelerating phase, such that the acceleration parameter $q(t)$ changes from positive to negative values and the equation of state parameter $Ï_ξ(t)$ tends to $-1$ at late times, similar to quintessence dark energy. Unlike the case $n=1$, in this case, no transition to the phantom phase is observed. Therefore, this model can describe the behavior of the universe during periods of dark energy dominance.
Yusuf Kucukakca、Fereshteh Omidvar、Amin Rezaei Akbarieh
物理学
Yusuf Kucukakca,Fereshteh Omidvar,Amin Rezaei Akbarieh.Exact Solutions for a Teleparallel Cosmological Model with Vector Field via Noether Symmetry[EB/OL].(2025-08-25)[2025-09-06].https://arxiv.org/abs/2508.17795.点此复制
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