<p>We investigate the cosmological implications of strange quark matter in a four-dimensional locally rotationally symmetric (LRS) Bianchi type-III universe within the framework of General Relativity. By adopting the MIT bag equation of state, exact analytical solutions of the Einstein field equations are obtained for different expansion phases of the universe, in which the bag constant naturally emerges as an effective vacuum energy component. The resulting cosmological evolution exhibits a transition from an early radiation-dominated. The Hubble parameter is explicitly expressed as a function of redshift and confronted with cosmic chronometer and baryon acoustic oscillation data using a Markov Chain Monte Carlo analysis. The combined CC+BAO constraints <Equation ID="Equa"> <EquationSource Format="MATHML"><math> <msub> <mi>H</mi> <mn>0</mn> </msub> <mo>=</mo> <msubsup> <mn>69.91</mn> <mrow> <mo>−</mo> <mn>1.94</mn> </mrow> <mrow> <mo>+</mo> <mn>2.43</mn> </mrow> </msubsup> <mspace width="0.3em" /> <mtext>km</mtext> <mspace width="0.2em" /> <msup> <mtext>s</mtext> <mrow> <mo>−</mo> <mn>1</mn> </mrow> </msup> <mspace width="0.2em" /> <msup> <mtext>Mpc</mtext> <mrow> <mo>−</mo> <mn>1</mn> </mrow> </msup> <mo>,</mo> <mspace width="1em" /> <msub> <mi mathvariant="normal">Ω</mi> <mi mathvariant="normal">Λ</mi> </msub> <mo>=</mo> <msubsup> <mn>0.59</mn> <mrow> <mo>−</mo> <mn>0.18</mn> </mrow> <mrow> <mo>+</mo> <mn>0.11</mn> </mrow> </msubsup> <mo>,</mo> <mspace width="1em" /> <msub> <mi mathvariant="normal">Ω</mi> <mi>k</mi> </msub> <mo>=</mo> <msubsup> <mn>0.37</mn> <mrow> <mo>−</mo> <mn>0.12</mn> </mrow> <mrow> <mo>+</mo> <mn>0.09</mn> </mrow> </msubsup> <mo>,</mo> </math></EquationSource> <EquationSource Format="TEX">$ H_{0} = 69.91^{+2.43}_{-1.94}~\mbox{km}\,\mbox{s}^{-1}\,\mbox{Mpc}^{-1}, \quad \Omega _{\Lambda }= 0.59^{+0.11}_{-0.18}, \quad \Omega _{k} = 0.37^{+0.09}_{-0.12}, $</EquationSource> </Equation> provides a qualitatively consistent description of anisotropic strange quark matter models while remaining consistent with late-time expansion measurements within a negatively curved cosmological framework. Although the imposed LRS symmetry leads to vanishing shear and effective isotropization, the intrinsic spatial curvature remains dynamically relevant at early times and leaves observable imprints on the expansion history of the universe. These results indicate that strange quark matter, through its bag constant contribution, can provide an effective and consistent description unifying early radiation-dominated evolution with late-time cosmic acceleration.</p>

Strange quark matter cosmology in LRS Bianchi type-III universe

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发表日期：

2026年4月16日

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A Patra,
S Panda,
R. N Patra

摘要

We investigate the cosmological implications of strange quark matter in a four-dimensional locally rotationally symmetric (LRS) Bianchi type-III universe within the framework of General Relativity. By adopting the MIT bag equation of state, exact analytical solutions of the Einstein field equations are obtained for different expansion phases of the universe, in which the bag constant naturally emerges as an effective vacuum energy component. The resulting cosmological evolution exhibits a transition from an early radiation-dominated. The Hubble parameter is explicitly expressed as a function of redshift and confronted with cosmic chronometer and baryon acoustic oscillation data using a Markov Chain Monte Carlo analysis. The combined CC+BAO constraints $H_{0} = {69.91}_{- 1.94}^{+ 2.43} km s^{- 1} {Mpc}^{- 1}, Ω_{Λ} = {0.59}_{- 0.18}^{+ 0.11}, Ω_{k} = {0.37}_{- 0.12}^{+ 0.09},$ $ H_{0} = 69.91^{+2.43}_{-1.94}~\mbox{km}\,\mbox{s}^{-1}\,\mbox{Mpc}^{-1}, \quad \Omega _{\Lambda }= 0.59^{+0.11}_{-0.18}, \quad \Omega _{k} = 0.37^{+0.09}_{-0.12}, $ provides a qualitatively consistent description of anisotropic strange quark matter models while remaining consistent with late-time expansion measurements within a negatively curved cosmological framework. Although the imposed LRS symmetry leads to vanishing shear and effective isotropization, the intrinsic spatial curvature remains dynamically relevant at early times and leaves observable imprints on the expansion history of the universe. These results indicate that strange quark matter, through its bag constant contribution, can provide an effective and consistent description unifying early radiation-dominated evolution with late-time cosmic acceleration.