<p>Our analysis focuses on the Generalized Chaplygin Gas (GCG) model within the <InlineEquation ID="IEq3"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10509_2025_4483_Article_IEq1.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="68" /> </InlineMediaObject> <EquationSource Format="MATHML"><math> <mi>f</mi> <mo stretchy="false">(</mo> <mi>Q</mi> <mo>,</mo> <msub> <mi>L</mi> <mi>m</mi> </msub> <mo stretchy="false">)</mo> </math></EquationSource> <EquationSource Format="TEX">$f(Q, L_{m})$</EquationSource> </InlineEquation> gravity framework, assuming <InlineEquation ID="IEq4"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10509_2025_4483_Article_IEq4.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="165" /> </InlineMediaObject> <EquationSource Format="MATHML"><math> <mi>f</mi> <mo stretchy="false">(</mo> <mi>Q</mi> <mo>,</mo> <msub> <mi>L</mi> <mi>m</mi> </msub> <mo stretchy="false">)</mo> <mo>=</mo> <mi>β</mi> <mi>Q</mi> <mo>+</mo> <mi>δ</mi> <msub> <mi>L</mi> <mi>m</mi> </msub> </math></EquationSource> <EquationSource Format="TEX">$f(Q,L_{m})=\beta Q+\delta L_{m}$</EquationSource> </InlineEquation> with <InlineEquation ID="IEq5"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10509_2025_4483_Article_IEq5.gif" Format="GIF" Height="17" Rendition="HTML" Resolution="72" Type="Linedraw" Width="70" /> </InlineMediaObject> <EquationSource Format="MATHML"><math> <msub> <mi>L</mi> <mi>m</mi> </msub> <mo>=</mo> <mo>−</mo> <mi>ρ</mi> </math></EquationSource> <EquationSource Format="TEX">$L_{m}=-\rho $</EquationSource> </InlineEquation>. Using the GCG equation of state <InlineEquation ID="IEq6"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10509_2025_4483_Article_IEq6.gif" Format="GIF" Height="25" Rendition="HTML" Resolution="72" Type="Linedraw" Width="61" /> </InlineMediaObject> <EquationSource Format="MATHML"><math> <mi>p</mi> <mo>=</mo> <mo>−</mo> <mfrac> <mi>A</mi> <msup> <mi>ρ</mi> <mi>α</mi> </msup> </mfrac> </math></EquationSource> <EquationSource Format="TEX">$p=-\frac{A}{\rho ^{\alpha }}$</EquationSource> </InlineEquation>, we derive expressions for energy density <InlineEquation ID="IEq7"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10509_2025_4483_Article_IEq7.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="32" /> </InlineMediaObject> <EquationSource Format="MATHML"><math> <mi>ρ</mi> <mo stretchy="false">(</mo> <mi>z</mi> <mo stretchy="false">)</mo> </math></EquationSource> <EquationSource Format="TEX">$\rho (z)$</EquationSource> </InlineEquation> and the Hubble parameter <InlineEquation ID="IEq8"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10509_2025_4483_Article_IEq8.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="38" /> </InlineMediaObject> <EquationSource Format="MATHML"><math> <mi>H</mi> <mo stretchy="false">(</mo> <mi>z</mi> <mo stretchy="false">)</mo> </math></EquationSource> <EquationSource Format="TEX">$H(z)$</EquationSource> </InlineEquation>. Constraining parameters through MCMC analysis with 31 cosmic chronometers, 15 BAO points, recent DESI DR2 BAO points and 1701 Pantheon+, we find best-fit values <InlineEquation ID="IEq9"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10509_2025_4483_Article_IEq9.gif" Format="GIF" Height="22" Rendition="HTML" Resolution="72" Type="Linedraw" Width="124" /> </InlineMediaObject> <EquationSource Format="MATHML"><math> <msub> <mi>H</mi> <mn>0</mn> </msub> <mo>=</mo> <msubsup> <mn>74.026</mn> <mrow> <mo>−</mo> <mn>3.317</mn> </mrow> <mrow> <mo>+</mo> <mn>3.332</mn> </mrow> </msubsup> </math></EquationSource> <EquationSource Format="TEX">$H_{0}=74.026^{+3.332}_{-3.317}$</EquationSource> </InlineEquation> km/s/Mpc, <InlineEquation ID="IEq10"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10509_2025_4483_Article_IEq10.gif" Format="GIF" Height="22" Rendition="HTML" Resolution="72" Type="Linedraw" Width="115" /> </InlineMediaObject> <EquationSource Format="MATHML"><math> <msub> <mi>A</mi> <mi>s</mi> </msub> <mo>=</mo> <msubsup> <mn>0.880</mn> <mrow> <mo>−</mo> <mn>0.020</mn> </mrow> <mrow> <mo>+</mo> <mn>0.019</mn> </mrow> </msubsup> </math></EquationSource> <EquationSource Format="TEX">$A_{s}=0.880^{+0.019}_{-0.020}$</EquationSource> </InlineEquation> and <InlineEquation ID="IEq11"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10509_2025_4483_Article_IEq11.gif" Format="GIF" Height="22" Rendition="HTML" Resolution="72" Type="Linedraw" Width="120" /> </InlineMediaObject> <EquationSource Format="MATHML"><math> <mi>α</mi> <mo>=</mo> <mo>−</mo> <msubsup> <mn>0.001</mn> <mrow> <mo>−</mo> <mn>0.052</mn> </mrow> <mrow> <mo>+</mo> <mn>0.053</mn> </mrow> </msubsup> </math></EquationSource> <EquationSource Format="TEX">$\alpha =-0.001^{+0.053}_{-0.052}$</EquationSource> </InlineEquation> which are consistent with local measurements. The deceleration parameter transitions at <InlineEquation ID="IEq12"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10509_2025_4483_Article_IEq12.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="71" /> </InlineMediaObject> <EquationSource Format="MATHML"><math> <msub> <mi>z</mi> <mrow> <mi>t</mi> <mi>r</mi> </mrow> </msub> <mo>≈</mo> <mn>0.79</mn> </math></EquationSource> <EquationSource Format="TEX">$z_{tr} \approx 0.79$</EquationSource> </InlineEquation>, with present value <InlineEquation ID="IEq13"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10509_2025_4483_Article_IEq13.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="80" /> </InlineMediaObject> <EquationSource Format="MATHML"><math> <msub> <mi>q</mi> <mn>0</mn> </msub> <mo>=</mo> <mo>−</mo> <mn>0.61</mn> </math></EquationSource> <EquationSource Format="TEX">$q_{0}=-0.61$</EquationSource> </InlineEquation>, while the equation of state evolves toward <InlineEquation ID="IEq14"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10509_2025_4483_Article_IEq14.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="56" /> </InlineMediaObject> <EquationSource Format="MATHML"><math> <mi>ω</mi> <mo>=</mo> <mo>−</mo> <mn>1</mn> </math></EquationSource> <EquationSource Format="TEX">$\omega =-1$</EquationSource> </InlineEquation> with <InlineEquation ID="IEq15"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10509_2025_4483_Article_IEq15.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="83" /> </InlineMediaObject> <EquationSource Format="MATHML"><math> <msub> <mi>ω</mi> <mn>0</mn> </msub> <mo>≈</mo> <mo>−</mo> <mn>0.79</mn> </math></EquationSource> <EquationSource Format="TEX">$\omega _{0} \approx -0.79$</EquationSource> </InlineEquation>. Energy conditions are satisfied except for the SEC, which is violated during acceleration. The model predicts a cosmic age of 13.42 Gyr and shows freezing quintessence behavior in the <InlineEquation ID="IEq16"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10509_2025_4483_Article_IEq16.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="50" /> </InlineMediaObject> <EquationSource Format="MATHML"><math> <mi>ω</mi> <mo>−</mo> <msup> <mi>ω</mi> <mo>′</mo> </msup> </math></EquationSource> <EquationSource Format="TEX">$\omega -\omega '$</EquationSource> </InlineEquation> plane, confirming its potential as a viable dark energy candidate.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Observational viability of generalized Chaplygin gas in \(f(Q, L_{m})\) gravity

  • Amit Samaddar,
  • S. Surendra Singh

摘要

Our analysis focuses on the Generalized Chaplygin Gas (GCG) model within the f ( Q , L m ) $f(Q, L_{m})$ gravity framework, assuming f ( Q , L m ) = β Q + δ L m $f(Q,L_{m})=\beta Q+\delta L_{m}$ with L m = ρ $L_{m}=-\rho $ . Using the GCG equation of state p = A ρ α $p=-\frac{A}{\rho ^{\alpha }}$ , we derive expressions for energy density ρ ( z ) $\rho (z)$ and the Hubble parameter H ( z ) $H(z)$ . Constraining parameters through MCMC analysis with 31 cosmic chronometers, 15 BAO points, recent DESI DR2 BAO points and 1701 Pantheon+, we find best-fit values H 0 = 74.026 3.317 + 3.332 $H_{0}=74.026^{+3.332}_{-3.317}$ km/s/Mpc, A s = 0.880 0.020 + 0.019 $A_{s}=0.880^{+0.019}_{-0.020}$ and α = 0.001 0.052 + 0.053 $\alpha =-0.001^{+0.053}_{-0.052}$ which are consistent with local measurements. The deceleration parameter transitions at z t r 0.79 $z_{tr} \approx 0.79$ , with present value q 0 = 0.61 $q_{0}=-0.61$ , while the equation of state evolves toward ω = 1 $\omega =-1$ with ω 0 0.79 $\omega _{0} \approx -0.79$ . Energy conditions are satisfied except for the SEC, which is violated during acceleration. The model predicts a cosmic age of 13.42 Gyr and shows freezing quintessence behavior in the ω ω $\omega -\omega '$ plane, confirming its potential as a viable dark energy candidate.