Both microlensing surveys and radio-frequency observations of gas flow imply that the inner Milky Way is completely dominated by baryons , contrary to the predictions of standard cold dark matter ( CDM ) cosmology .
We investigate the predictions of the Modified Newtonian Dynamics ( MOND ) formula for the Galaxy given the measured baryon distribution .
Satisfactory fits to the observationally determined terminal-velocity curve are obtained for different choices of the MOND ’ s interpolating function \mu ( x ) .
However , with simple analytical forms of \mu ( x ) , the local circular speed v _ { c } ( R _ { 0 } ) can be as large as 220 { km s ^ { -1 } } only for values of the parameter a _ { 0 } that are excluded by observations of NGC 3198 .
Only a numerically specified interpolating function can produce v _ { c } ( R _ { 0 } ) = 220 { km s ^ { -1 } } , which is therefore an upper limit in MOND , while the asymptotic velocity is predicted to be v _ { c } ( \infty ) = 170 \pm 5 { km s ^ { -1 } } .
The data are probably not consistent with the functional form of \mu ( x ) that has been explored as a toy model in the framework of Bekenstein ’ s covariant theory of gravity .