Late time acceleration due to generic modification of gravity and Hubble tension. (arXiv:2106.03093v2 [astro-ph.CO] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Adil_S/0/1/0/all/0/1">Shahnawaz A. Adil</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gangopadhyay_M/0/1/0/all/0/1">Mayukh R. Gangopadhyay</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sami_M/0/1/0/all/0/1">M. Sami</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sharma_M/0/1/0/all/0/1">Mohit K. Sharma</a>
We consider a scenario of modified gravity, which is generic to late-time
acceleration, namely, acceleration in the Jordan frame and no acceleration in
the Einstein frame. The possibility is realized by assuming an interaction
between dark matter and the baryonic component in the Einstein frame which is
removed by going to the Jordan frame using a disformal transformation giving
rise to an exotic effective fluid responsible for causing phantom crossing at
late times. In this scenario, past evolution is not distinguished from
$Lambda$CDM but late time dynamics is generically different due to the
presence of phantom crossing that causes a monotonous increase in the expansion
rate giving rise to distinctive late-time cosmic feature. The latter can play a
crucial role in addressing the tension between the observed value of Hubble
parameter by CMB (Cosmic Microwave Background) measurements and the local
observations. We demonstrate that the Hubble tension significantly reduces in
the scenario under consideration for the chosen scale factor parametrizations.
The estimated age of the universe in the model is well within the observational
bounds in the low and high red-shift regimes.
We consider a scenario of modified gravity, which is generic to late-time
acceleration, namely, acceleration in the Jordan frame and no acceleration in
the Einstein frame. The possibility is realized by assuming an interaction
between dark matter and the baryonic component in the Einstein frame which is
removed by going to the Jordan frame using a disformal transformation giving
rise to an exotic effective fluid responsible for causing phantom crossing at
late times. In this scenario, past evolution is not distinguished from
$Lambda$CDM but late time dynamics is generically different due to the
presence of phantom crossing that causes a monotonous increase in the expansion
rate giving rise to distinctive late-time cosmic feature. The latter can play a
crucial role in addressing the tension between the observed value of Hubble
parameter by CMB (Cosmic Microwave Background) measurements and the local
observations. We demonstrate that the Hubble tension significantly reduces in
the scenario under consideration for the chosen scale factor parametrizations.
The estimated age of the universe in the model is well within the observational
bounds in the low and high red-shift regimes.
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