<p>We investigate late–time cosmology in the Finsler–Barthel–Kropina framework, where anisotropic effects are introduced into the FLRW background through a time–dependent function <InlineEquation ID="IEq1"> <EquationSource Format="MATHML"><math> <mi>η</mi> <mo stretchy="false">(</mo> <mi>t</mi> <mo stretchy="false">)</mo> </math></EquationSource> <EquationSource Format="TEX">$\eta (t)$</EquationSource> </InlineEquation> constructed via the osculating Riemannian approach. The resulting modified Friedmann equations generate direction–dependent corrections to the expansion history. Using Cosmic Chronometers (CC), DESI BAO, and Pantheon+ supernova observations, we reconstruct the Hubble rate, energy density, and key cosmographic quantities. The model yields <InlineEquation ID="IEq2"> <EquationSource Format="MATHML"><math> <msub> <mi>H</mi> <mn>0</mn> </msub> </math></EquationSource> <EquationSource Format="TEX">$H_{0}$</EquationSource> </InlineEquation> values consistent with late–time observations and negative value of deceleration parameter at present indicates ongoing acceleration phase of universe, while the reconstructed jerk and <InlineEquation ID="IEq3"> <EquationSource Format="MATHML"><math> <mi>O</mi> <mi>m</mi> <mo stretchy="false">(</mo> <mi>z</mi> <mo stretchy="false">)</mo> </math></EquationSource> <EquationSource Format="TEX">$Om(z)$</EquationSource> </InlineEquation> diagnostics show clear departures from constant–<InlineEquation ID="IEq4"> <EquationSource Format="MATHML"><math> <mi mathvariant="normal">Λ</mi> </math></EquationSource> <EquationSource Format="TEX">$\Lambda $</EquationSource> </InlineEquation> evolution, indicating effective dark-energy like dynamics sourced by Finslerian anisotropy. The predicted cosmic age is slightly higher than <InlineEquation ID="IEq5"> <EquationSource Format="MATHML"><math> <mi mathvariant="normal">Λ</mi> </math></EquationSource> <EquationSource Format="TEX">$\Lambda $</EquationSource> </InlineEquation>CDM. A model selection analysis based on information criteria shows that the Finsler–Kropina model performs competitively with <InlineEquation ID="IEq6"> <EquationSource Format="MATHML"><math> <mi mathvariant="normal">Λ</mi> </math></EquationSource> <EquationSource Format="TEX">$\Lambda $</EquationSource> </InlineEquation>CDM for the CC+ DESI BAO dataset, whereas the full joint dataset mildly favors <InlineEquation ID="IEq7"> <EquationSource Format="MATHML"><math> <mi mathvariant="normal">Λ</mi> </math></EquationSource> <EquationSource Format="TEX">$\Lambda $</EquationSource> </InlineEquation>CDM due to its lower parameter complexity. This demonstrates that Finsler–Kropina geometry offers a viable anisotropic extension of late–time cosmology.</p>

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Observational constraints on anisotropic cosmology and dark energy in Finsler–Kropina models

  • J. Praveen,
  • S. K. Narasimhamurthy

摘要

We investigate late–time cosmology in the Finsler–Barthel–Kropina framework, where anisotropic effects are introduced into the FLRW background through a time–dependent function η ( t ) $\eta (t)$ constructed via the osculating Riemannian approach. The resulting modified Friedmann equations generate direction–dependent corrections to the expansion history. Using Cosmic Chronometers (CC), DESI BAO, and Pantheon+ supernova observations, we reconstruct the Hubble rate, energy density, and key cosmographic quantities. The model yields H 0 $H_{0}$ values consistent with late–time observations and negative value of deceleration parameter at present indicates ongoing acceleration phase of universe, while the reconstructed jerk and O m ( z ) $Om(z)$ diagnostics show clear departures from constant– Λ $\Lambda $ evolution, indicating effective dark-energy like dynamics sourced by Finslerian anisotropy. The predicted cosmic age is slightly higher than Λ $\Lambda $ CDM. A model selection analysis based on information criteria shows that the Finsler–Kropina model performs competitively with Λ $\Lambda $ CDM for the CC+ DESI BAO dataset, whereas the full joint dataset mildly favors Λ $\Lambda $ CDM due to its lower parameter complexity. This demonstrates that Finsler–Kropina geometry offers a viable anisotropic extension of late–time cosmology.