Dynamical Stability of Bulk Viscous Isotropic and Homogeneous Universe
In this paper, we study the phase space portrait of homogeneous and isotropic universe by taking different coupling functions between dark energy models and bulk viscous dark matter. The dimensionless quantities are introduced to establish an autonomous set of equations. To analyze the stability of...
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| Format: | Article |
| Language: | English |
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MDPI AG
2019-08-01
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| Series: | Universe |
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| Online Access: | https://www.mdpi.com/2218-1997/5/8/185 |
| _version_ | 1811212943583346688 |
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| author | Muhammad Sharif Qanitah Ama-Tul-Mughani |
| author_facet | Muhammad Sharif Qanitah Ama-Tul-Mughani |
| author_sort | Muhammad Sharif |
| collection | DOAJ |
| description | In this paper, we study the phase space portrait of homogeneous and isotropic universe by taking different coupling functions between dark energy models and bulk viscous dark matter. The dimensionless quantities are introduced to establish an autonomous set of equations. To analyze the stability of the cosmos, we evaluate critical points and respective eigenvalues for different dynamical quantities. For bulk viscous matter and radiation in tachyon coupled field, these points show stable evolution when <inline-formula> <math display="inline"> <semantics> <mrow> <mi>γ</mi> <mo>≫</mo> <mi>δ</mi> </mrow> </semantics> </math> </inline-formula> but accelerated expansion of the universe for <inline-formula> <math display="inline"> <semantics> <mrow> <mi>δ</mi> <mo>></mo> <mfrac> <mn>1</mn> <mn>9</mn> </mfrac> </mrow> </semantics> </math> </inline-formula>. The stability of the universe increases for some stationary points which may correspond to the late-time expansion for the coupled phantom field. |
| first_indexed | 2024-04-12T05:38:08Z |
| format | Article |
| id | doaj.art-cfb70e02c4004119997ff829a1940ec5 |
| institution | Directory Open Access Journal |
| issn | 2218-1997 |
| language | English |
| last_indexed | 2024-04-12T05:38:08Z |
| publishDate | 2019-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Universe |
| spelling | doaj.art-cfb70e02c4004119997ff829a1940ec52022-12-22T03:45:46ZengMDPI AGUniverse2218-19972019-08-015818510.3390/universe5080185universe5080185Dynamical Stability of Bulk Viscous Isotropic and Homogeneous UniverseMuhammad Sharif0Qanitah Ama-Tul-Mughani1Department of Mathematics, University of the Punjab, Quaid-e-Azam Campus, Lahore-54590, PakistanDepartment of Mathematics, University of the Punjab, Quaid-e-Azam Campus, Lahore-54590, PakistanIn this paper, we study the phase space portrait of homogeneous and isotropic universe by taking different coupling functions between dark energy models and bulk viscous dark matter. The dimensionless quantities are introduced to establish an autonomous set of equations. To analyze the stability of the cosmos, we evaluate critical points and respective eigenvalues for different dynamical quantities. For bulk viscous matter and radiation in tachyon coupled field, these points show stable evolution when <inline-formula> <math display="inline"> <semantics> <mrow> <mi>γ</mi> <mo>≫</mo> <mi>δ</mi> </mrow> </semantics> </math> </inline-formula> but accelerated expansion of the universe for <inline-formula> <math display="inline"> <semantics> <mrow> <mi>δ</mi> <mo>></mo> <mfrac> <mn>1</mn> <mn>9</mn> </mfrac> </mrow> </semantics> </math> </inline-formula>. The stability of the universe increases for some stationary points which may correspond to the late-time expansion for the coupled phantom field.https://www.mdpi.com/2218-1997/5/8/185stabilityphase space analysisbulk viscosity |
| spellingShingle | Muhammad Sharif Qanitah Ama-Tul-Mughani Dynamical Stability of Bulk Viscous Isotropic and Homogeneous Universe Universe stability phase space analysis bulk viscosity |
| title | Dynamical Stability of Bulk Viscous Isotropic and Homogeneous Universe |
| title_full | Dynamical Stability of Bulk Viscous Isotropic and Homogeneous Universe |
| title_fullStr | Dynamical Stability of Bulk Viscous Isotropic and Homogeneous Universe |
| title_full_unstemmed | Dynamical Stability of Bulk Viscous Isotropic and Homogeneous Universe |
| title_short | Dynamical Stability of Bulk Viscous Isotropic and Homogeneous Universe |
| title_sort | dynamical stability of bulk viscous isotropic and homogeneous universe |
| topic | stability phase space analysis bulk viscosity |
| url | https://www.mdpi.com/2218-1997/5/8/185 |
| work_keys_str_mv | AT muhammadsharif dynamicalstabilityofbulkviscousisotropicandhomogeneousuniverse AT qanitahamatulmughani dynamicalstabilityofbulkviscousisotropicandhomogeneousuniverse |