A general class of gravitational theories as alternatives to dark matter where the speed of gravity always equals the speed of light. (arXiv:1905.09465v1 [gr-qc])
<a href="http://arxiv.org/find/gr-qc/1/au:+Skordis_C/0/1/0/all/0/1">Constantinos Skordis</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Zlosnik_T/0/1/0/all/0/1">Tom Zlosnik</a>

A number of theories of gravity have been proposed as proxies for dark matter
in the regime of galaxies and cosmology. The recent observations of
gravitational waves (GW170817) from the merger of two neutron stars, followed
by an electromagnetic counterpart (GW170817a) have placed stringent constraints
on the difference of the speed of gravity to the speed of light, severely
restricting the phenomenological viability of such theories. We revisit the
impact of these observations on the Tensor-Vector-Scalar (TeVeS) paradigm of
relativistic Modified Newtonian Dynamics (MOND) and demonstrate the existence
of a previously unknown class of this paradigm where the speed of gravity
always equals the speed of light. We show that this holds without altering the
usual (bimetric) MOND phenomenology in galaxies.

A number of theories of gravity have been proposed as proxies for dark matter
in the regime of galaxies and cosmology. The recent observations of
gravitational waves (GW170817) from the merger of two neutron stars, followed
by an electromagnetic counterpart (GW170817a) have placed stringent constraints
on the difference of the speed of gravity to the speed of light, severely
restricting the phenomenological viability of such theories. We revisit the
impact of these observations on the Tensor-Vector-Scalar (TeVeS) paradigm of
relativistic Modified Newtonian Dynamics (MOND) and demonstrate the existence
of a previously unknown class of this paradigm where the speed of gravity
always equals the speed of light. We show that this holds without altering the
usual (bimetric) MOND phenomenology in galaxies.

http://arxiv.org/icons/sfx.gif