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Galaxy rotation curves determined observationally out to a radius well beyond the galaxy cores can provide a critical test of modified gravity models without dark matter. The predicted rotational velocity curve obtained from scalar-vector-tensor gravity is in excellent agreement with data for the Milky Way without a dark matter halo, with a mass of 5 × 1010M☉. The velocity rotation curve predicted by modified Newtonian dynamics does not agree with the data. [ABSTRACT FROM AUTHOR]

The temperature dependence of the infrared absorption spectrum of ZnSe was measured by using a variable temperature, liquid nitrogen cooled, absorption cell interfaced with a Fourier transform infrared spectrometer. Absorption difference spectra were obtained as a function of temperature by using the on-board computing facilities of the spectrometer coupled with its data storage capabilities. The temperature dependence of the absorption feature, which extends from about 450 to 800 cm −1, is shown to be consistent with a two phonon interaction as have been previously suggested.

The lensing and Einstein ring at the core of the galaxy cluster Abell 3827 are reproduced in the modified gravity theory (MOG). The estimated effective lensing mass ML=(1+α)Mb=5.2×1012 M⊙ within R=18.3  kpc for a baryon mass Mb=1.0×1012 M⊙ within the same radius produces the observed Einstein ring angular radius θE=10". A detailed derivation of the total lensing mass is based on modeling of the cluster configuration of galaxies, intracluster light and x-ray emission. The MOG can fit the lensing and Einstein ring in Abell 3827 without dark matter as well as general relativity with dark matter. [ABSTRACT FROM AUTHOR]

We present calculations for the anticipated shadow sizes of Sgr A* and the supermassive black hole in the galaxy M87 in the context of the MOG modified theory of gravitation (also known as Scalar-Tensor-Vector-Gravity). We demonstrate that mass estimates derived from stellar and gas dynamics in the vicinity of these black holes are the Newtonian masses of the black holes even in the MOG theory. Consequently, shadow sizes increase as a function of the key dimensionless MOG parameter α that characterizes the variable gravitational coupling coefficient G and may offer an observational means to distinguish the MOG theory from standard general relativity. [ABSTRACT FROM AUTHOR]