Related papers: Maximum Mass-Radius Ratios for Charged Compact Gen…
We generalise the Buchdahl-Bondi limit for the case of static, spherically symmetric, relativistic compact stars immersed in Schwarzschild vacuum in f(R)-theory of gravity, subject to very generic regularity, thermodynamic stability and…
Planets have maximum radii close to that of Jupiter. Qualitatively, the reason for this maximum size is that, as one adds mass, the force of gravity becomes sufficiently strong to cause the radius to decrease. We show that this effect can…
Precise and reliable measurements of the masses and radii of neutron stars with a variety of masses would provide valuable guidance for improving models of the properties of cold matter with densities above the saturation density of nuclear…
Recent literature has seen an ongoing discussion on the limiting mass of strongly magnetized white dwarfs, since such objects may prove to be a source of over-luminous type-Ia supernovae. In an earlier paper, we have presented the…
We study the effects of anisotropic pressure on the properties of spherically symmetric, gravitationally bound objects. We consider the full general relativistic treatment of this problem and obtain exact solutions for various form of…
Neutron stars, produced at the death of massive stars, are often regarded as giant neutron-rich nuclei. This picture is especially relevant for low-mass (below about solar mass) neutron stars, where non-nucleonic components are not expected…
We present early results from a Hubble Space Telescope (HST) WFC3/IR imaging survey of star-forming galaxies in the redshift range 1.5 < z < 3.0. When complete, this survey will consist of 42 orbits of F160W imaging distributed amongst 10…
Causality alone suffices to set a lower bound on the period of rotation of relativistic stars as a function of their maximum observed mass. That is, by assuming a one-parameter equation of state (EOS) that satisfies v_sound < c and that…
By using elementary astrophysical concepts, we show that for any self-luminous astrophysical object, the ratio of radiation energy density inside the body (rho_r) and the baryonic energy density (rho_0) may be crudely approximated, in the…
We investigate the equations of state for pure neutron matter and strange hadronic matter in $\beta$-equilibrium, including $\Lambda$, $\Sigma$ and $\Xi$ hyperons. The masses and radii of pure neutron stars and strange hadronic stars are…
We revisit the determination of binary mass ratio in the Galactic microquasar SS433 based on recent GRAVITY VLTI measurements of mass and angular momentum outflow through a circumbinary disc. The new observations combined with the constancy…
Observational identification of black holes as members of binary systems requires the knowledge of the upper limit on the gravitational mass of a neutron star. We use modern equations of state for neutron star matter, fitted to experimental…
Considering the observed anisotropy in cosmic microwave background radiation ($\Delta T/T \leq 10^{-4}$) an upper limit on the electric charge asymmetry over a cosmological scale is found which is several orders more stringent than those…
The maximum size of a cosmic structure is given by the maximum turnaround radius -- the scale where the attraction due to its mass is balanced by the repulsion due to dark energy. We derive generic formulae for the estimation of the maximum…
In this research, we introduce magnetically charged stars in the framework of non-singular metric which is explained with nonlinear electrodynamics(NED). This model allows us to have an upper limit for the maximum limit for the mass of…
We prove that in the family of static, asymptotically flat, spherically symmetric scalar hairy black holes with the central electric charge, the set of the charge-to-mass ratios has the exact upper bound $3\sqrt{2}/4\approx1.06$.
We study the lifetimes of the remnant produced by the merger of two neutron stars and revisit the determination of the threshold mass to prompt collapse, $M_{\rm th}$. Using a fully general-relativistic numerical approach and a novel method…
We show how gravitational-wave observations with advanced detectors of tens to several tens of neutron-star binaries can measure the neutron-star radius with an accuracy of several to a few percent, for mass and spatial distributions that…
We show that microscopic calculations based on chiral effective field theory interactions constrain the properties of neutron-rich matter below nuclear densities to a much higher degree than is reflected in commonly used equations of state.…
The formation of the most massive quasars observed at high redshifts requires extreme inflows of gas down to the length scales of the central compact object. Here, we estimate the maximum inflow rate allowed by gravity down to the surface…