Constrain the Rastall parameters in static spacetimes with galaxy-sclale strong gravitational lensing. (arXiv:1903.08790v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Li_R/0/1/0/all/0/1">Rui Li</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_J/0/1/0/all/0/1">Jiancheng Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Xu_Z/0/1/0/all/0/1">Zhaoyi Xu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Guo_X/0/1/0/all/0/1">Xiaotong Guo</a>

Recently, Rastall gravity is undergoing a significant surge in popularity. We
naturally obtain a power-law total mass-density profile for the inner regions
(within several effective radius) of early-type galaxies (ETGs) from the
space-time structures which are described by the static spherically-symmetric
solutions of Rastall gravity under the assumption of the perfect fluid matter.
We find that in the inner region of ETGs, the Rastall dimensionless parameter
$beta=kappalambda$ determines the mass distribution. We then use 118
galaxy-galaxy strong gravitational lensing systems to constrain the Rastall
dimensionless parameter $beta$. We find that the mean value of $beta$ for
total 118 ETGs is $beta=0.163pm0.001$(68% CL) with a minor intrinsic scatter
of $delta=0.020pm 0.001$. Our work observationally illustrates the physical
meaning of theRastall dimensionless parameter in galaxy scale. From the
Newtonian approximation of Rastall gravity, we also find that an absolute
isothermal mass distribution for ETGs is not allowed in the Rastall gravity
framework.

Recently, Rastall gravity is undergoing a significant surge in popularity. We
naturally obtain a power-law total mass-density profile for the inner regions
(within several effective radius) of early-type galaxies (ETGs) from the
space-time structures which are described by the static spherically-symmetric
solutions of Rastall gravity under the assumption of the perfect fluid matter.
We find that in the inner region of ETGs, the Rastall dimensionless parameter
$beta=kappalambda$ determines the mass distribution. We then use 118
galaxy-galaxy strong gravitational lensing systems to constrain the Rastall
dimensionless parameter $beta$. We find that the mean value of $beta$ for
total 118 ETGs is $beta=0.163pm0.001$(68% CL) with a minor intrinsic scatter
of $delta=0.020pm 0.001$. Our work observationally illustrates the physical
meaning of theRastall dimensionless parameter in galaxy scale. From the
Newtonian approximation of Rastall gravity, we also find that an absolute
isothermal mass distribution for ETGs is not allowed in the Rastall gravity
framework.

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