Astronomy, Volume 1, Issue 3

We present the geometric optics expansion for circularly polarized gravitational waves on a curved spacetime background, to subleading order. We call spin optics to the subleading order geometric optics expansion, which involves modifying the standar...

Atomic and molecular data are required to conduct the detailed calculations of microphysical processes performed by cloudy to predict the spectra of a theoretical model. cloudy now utilizes three atomic and molecular databases, one of which is CHIANT...

A comparison of gravitational forces and a space probe’s trajectory parameters is made for two different models of the sun’s field, expressed in Schwarzschild and isotropic coordinates. It is shown that these two representations of a sing...

We doubt whether the “Energetic Neutral Atom (ENA) ribbon” signals, especially the peak ones, scanned remotely by IBEX-Hi at the lunar resonance orbit, are really from the heliopause, which involves assessing the scale of solar wind parti...

After their initial formation, disk galaxies are observed to be rotationally stable over periods of >6 Gyr, implying that any large velocity disturbances of stars and gas clouds are damped rapidly on the timescale of their rotation. However, it is...

We determine the k-essence Lagrangian of a relativistic barotropic fluid. The equation of state of the fluid can be specified in different manners depending on whether the pressure is expressed in terms of the energy density (model I), the rest-mass...