A neutron star with a strange quark star-like mass-radius relation
Publication date: Available online 7 February 2020Source: Physics of the Dark UniverseAuthor(s): A. Savaş Arapoğlu, A. Emrah YükselciAbstractWe study the structure of spherically symmetric and static objects in the presence of a nonminimally coupled scalar field having a potential of the form V(ϕ)=−μ2ϕ2∕2+λϕ4∕4. We numerically solve equations of the system using two different realistic equations of state for neutron matter and give the mass–radius relations as well as the radial profiles of the scalar field, densities and the mass function for a sample configuration. We show that a specific solution type en...
Source: Physics of the Dark Universe - February 8, 2020 Category: Physics Source Type: research
Fuzzy Euclidean wormholes in the inflationary universe
Publication date: Available online 5 February 2020Source: Physics of the Dark UniverseAuthor(s): Pisin Chen, Daeho Ro, Dong-han YeomAbstractIn this paper, we investigate complex-valued Euclidean wormholes in the Starobinsky inflation. Due to the properties of the concave inflaton potential, the classicality condition at both ends of the wormhole can be satisfied, as long as the initial condition of the inflaton field is such that it is located sufficiently close to the hilltop. We compare the probabilities of classicalized wormholes with the Hartle-Hawking compact instantons and conclude that the Euclidean wormholes are pr...
Source: Physics of the Dark Universe - February 7, 2020 Category: Physics Source Type: research
Analysis method for detecting topological defect dark matter with a global magnetometer network
Publication date: Available online 6 February 2020Source: Physics of the Dark UniverseAuthor(s): Hector Masia-Roig, Joseph A. Smiga, Dmitry Budker, Vincent Dumont, Zoran Grujic, Dongok Kim, Derek F. Jackson Kimball, Victor Lebedev, Madeline Monroy, Szymon Pustelny, Theo Scholtes, Perrin C. Segura, Yannis K. Semertzidis, Yun Chang Shin, Jason E. Stalnaker, Ibrahim Sulai, Antoine Weis, Arne WickenbrockAbstractThe Global Network of Optical Magnetometers for Exotic physics searches (GNOME) is a network of time-synchronized, geographically separated, optically pumped atomic magnetometers that is being used to search for correla...
Source: Physics of the Dark Universe - February 7, 2020 Category: Physics Source Type: research
Joint analysis of EDGES 21-cm line observations with standard candles and rulers in ΛCDM and non-adiabatic gCg models
Publication date: Available online 4 February 2020Source: Physics of the Dark UniverseAuthor(s): C. Pigozzo, S. Carneiro, J.C. FabrisAbstractA decomposed generalised Chaplygin gas (gCg) with energy flux from dark energy to dark matter, represented by a negative value for the gas parameter α, is shown to alleviate the tension between EDGES data and the cosmological standard model. Using EDGES data and employing a Bayesian statistical analysis, the agreement with the standard model is only marginal. However, if α is negative enough the gCg fits remarkably well the data, even in combination with SNe Ia datasets. On the othe...
Source: Physics of the Dark Universe - February 5, 2020 Category: Physics Source Type: research
On the change of old neutron star masses with galactocentric distance
Publication date: Available online 30 January 2020Source: Physics of the Dark UniverseAuthor(s): Antonino Del Popolo, Maksym Deliyergiyev, Morgan Le Delliou, Laura Tolos, Fiorella BurgioAbstractWe show that the pulsar mass depends on the environment, and that it decreases going towards the center of the Milky Way. This is due to two combined effects, the capture and accumulation of self-interacting, non-annihilating dark matter by pulsars, and the increase of the dark matter density going towards the galactic center. We show that mass decrease depends both on the density profile of dark matter, steeper profiles producing a...
Source: Physics of the Dark Universe - January 31, 2020 Category: Physics Source Type: research
