Related papers: Charged neutron stars and observational tests of a…
Many classes of extended scalar-tensor theories predict that dynamical instabilities can take place at high energies, leading to the formation of scalarized neutron stars. Depending on the theory parameters, stars in a scalarized state can…
Recent detections by the gravitational wave facilities LIGO/Virgo have opened a window to study the internal structure of neutron stars through the gravitational waves emitted during their coalescence. In this work we explore, through…
The origin of neutrino mass remains an open question in particle physics. One intriguing possibility is that neutrinos are massless in vacuum but acquire an effective refractive mass through interactions with ultralight dark matter during…
For nearly a century, Einstein's theory of gravity has been the standard theory for describing gravitational phenomena in our universe. Along with its successes, limitations of the theory from theoretical (e.g., singularities) and…
We consider a dark sector model containing stable fermions charged under an unbroken $U(1)$ gauge interaction, with a massless dark photon as force carrier, and interacting with ordinary matter via scalar messengers. We study its early…
Neutron stars are unique testbeds for exploring the physics of strongly interacting matter in extreme regimes of density, temperature, and isospin that are not accessible anywhere else in the universe. The nature of neutron star matter can…
In standard cosmologies, dark energy interacts only gravitationally with dark matter. There could be a non-gravitational interaction in the dark sector, leading to changes in the effective DE equation of state, in the redshift dependence of…
We report a measurement of the local acceleration $g$ with ultracold neutrons based on quantum states in the gravity potential of the Earth. The new method uses resonant transitions between the states $|1> -> |3>$ and for the first time…
We examine the possibility that dark matter (DM) may be an ultralight scalar that was misaligned via non-minimal coupling to gravity, in the early Universe. For a certain regime of scalar masses, gravitational effects in neutron stars could…
The detection of GW170817 and the identification of its host galaxy have allowed for the first standard-siren measurement of the Hubble constant, with an uncertainty of $\sim 14\%$. As more detections of binary neutron stars with redshift…
Gravitational wave (GW) standard siren observations provide a rather useful tool to explore the evolution of the Universe. In this work, we wish to investigate whether dark sirens with neutron star (NS) deformation from third-generation GW…
Neutron star observations, including direct mass and radius measurements as well as the analysis of gravitational wave signals emitted by stellar mergers, provide valuable and unique insights into the properties of strongly interacting…
In a recent paper we have shown that a minimally coupled, self-interacting scalar field of mass $m$ can form black holes of mass $M=\sqrt{3}/(4m)$ (in Planck units). If dark matter is composed by axions, they can form miniclusters that for…
We consider a long-range force, mediated by an ultralight scalar, which can give rise to violation of baryon number. This would lead to very different lifetimes for nucleons in different astrophysical environments. Possible signals of this…
Recent experimental observation suggests that neutron decay is always accompanied by emission of electron while in 1% of cases proton is not emitted. We develop a scenario kinematically compatible with experimental observation, where…
We observe that sub-GeV Dark Matter (DM) induces Casimir-Polder forces between nucleons, that can be accessed by experiments from nuclear to molecular scales. We calculate the nucleon-nucleon potentials arising in the DM effective theory…
The observable macroscopic properties of relativistic stars (whose equations of state are known) can be predicted by solving the stellar structure equations that follow from Einstein's equation. For neutron stars, however, our knowledge of…
The precise measurement of neutron star (NS) spins can provide important insight into the formation and evolution of compact binaries containing NS. While traditional methods of NS spin measurement rely on pulsar observations, gravitational…
By assuming that ultra dense hybrid neutron stars are endowed with a distribution of electric charge, we study the corresponding twin star solutions and their properties resulting from a sharp first order transition from confined hadronic…
Neutron stars contain a significant number of stable muons due to the large chemical potential and degenerate electrons. This makes them the unique vessel to capture muonphilic dark matter, which does not interact with other astrophysical…