Dynamical analysis of logarithmic energy-momentum squared gravity
Fuente:
arXiv
Gespeichert in:
| Hauptverfasser: | , |
|---|---|
| Format: | Preprint |
| Veröffentlicht: |
2022
|
| Schlagworte: | |
| Online-Zugang: | |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| _version_ | 1866913919625330688 |
|---|---|
| author | Acquaviva, Giovanni Katirci, Nihan |
| author_facet | Acquaviva, Giovanni Katirci, Nihan |
| contents | We perform the dynamical system analysis of a cosmological model in the energy-momentum squared gravity (EMSG) of the form $f(T_{μν} T^{μν})=α\ln(λT_{μν} T^{μν})$, which is known as energy-momentum log gravity (EMLG). In particular, we show that the analytical cosmological solution of EMLG presented by Akarsu {\it et al.} (Eur. Phys. J. C 79:846, 2019) is a future attractor. It includes new terms in the right-hand side of the Einstein field equations, which yield constant inertial mass density and provide a dynamical dark energy with a density passing below zero at large redshifts, accommodating a mechanism for screening $Λ$ in the past for $α<0$, suggested for alleviating some cosmological tensions. We show that the second law of thermodynamics requires $α\leq0$ that allows the screening mechanism to take place. We also show that the model gives rise to an entire class of new stable late-time solutions with $H\rightarrow\sqrt{(Λ+2α)/3}$ as $a\rightarrow\infty$, where the new term is due to the constant effective inertial mass density that arises from EMLG contribution of dust, whereas $H\rightarrow\sqrt{Λ/3}$ as $a\rightarrow\infty$ in the $Λ$CDM model. We also show the existence of new interesting features and trajectories that are absent in $Λ$CDM with or without spatial curvature. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2203_01234 |
| institution | arXiv |
| publishDate | 2022 |
| record_format | arxiv |
| spellingShingle | Dynamical analysis of logarithmic energy-momentum squared gravity Acquaviva, Giovanni Katirci, Nihan General Relativity and Quantum Cosmology Cosmology and Nongalactic Astrophysics We perform the dynamical system analysis of a cosmological model in the energy-momentum squared gravity (EMSG) of the form $f(T_{μν} T^{μν})=α\ln(λT_{μν} T^{μν})$, which is known as energy-momentum log gravity (EMLG). In particular, we show that the analytical cosmological solution of EMLG presented by Akarsu {\it et al.} (Eur. Phys. J. C 79:846, 2019) is a future attractor. It includes new terms in the right-hand side of the Einstein field equations, which yield constant inertial mass density and provide a dynamical dark energy with a density passing below zero at large redshifts, accommodating a mechanism for screening $Λ$ in the past for $α<0$, suggested for alleviating some cosmological tensions. We show that the second law of thermodynamics requires $α\leq0$ that allows the screening mechanism to take place. We also show that the model gives rise to an entire class of new stable late-time solutions with $H\rightarrow\sqrt{(Λ+2α)/3}$ as $a\rightarrow\infty$, where the new term is due to the constant effective inertial mass density that arises from EMLG contribution of dust, whereas $H\rightarrow\sqrt{Λ/3}$ as $a\rightarrow\infty$ in the $Λ$CDM model. We also show the existence of new interesting features and trajectories that are absent in $Λ$CDM with or without spatial curvature. |
| title | Dynamical analysis of logarithmic energy-momentum squared gravity |
| topic | General Relativity and Quantum Cosmology Cosmology and Nongalactic Astrophysics |
| url | https://arxiv.org/abs/2203.01234 |