Asymptotic Cosmological Behavior of Scalar-Torsion Mode in Poincare Gauge Theory

摘要

We study the cosmological effect of the simple scalar-torsion ($0^+$) mode inPoincar\'{e} gauge theory of gravity. We find that for the non-constant(affine) curvature case, the early evolution of the torsion density $\rho_T$has a radiation-like asymptotic behavior of $a^{-4}$ with $a$ representing thescale factor, along with the stable point of the torsion pressure ($P_T$) anddensity ratio $P_T/\rho_T\rightarrow 1/3$ in the high redshift regime $(z \gg0)$, which is different from the previous result in the literature. We use theLaurent expansion to resolve the solution. We also illustrate our result by theexecution of numerical computations.