相关论文: Remarkable analytic relations among greybody param…
In this work, we study a special form of Horndeski solutions, viz. quartic "square-root" Horndeski black hole immersed in a perfect-fluid dark-matter halo, by examining its thermodynamics, null geodesic shape, optical shadow, and…
We construct an analytic geodesic-optics description of quasinormal ringing, black-hole shadows, strong lensing, and grey-body factors for the static spherical metric introduced in [Bakopoulos, et. al. arXiv:2310.11919]. Working in a…
In this work we study the magnitude-redshift relation of a non-standard cosmological model. The model under consideration was firstly investigated within a special case of metric-affine gravity (MAG) and was recently recovered via different…
Recent observations by the Event Horizon Telescope (EHT) of supermassive black holes M87* and Sgr A* offer valuable insights into their spacetime properties and astrophysical conditions. Utilizing a library of model images (~2 million for…
We study various equilibrium thermodynamic properties of blackbody radiation (i.e. a photon gas) with an ultraviolet energy cut-off. We find that the energy density, specific heat etc. follow usual acoustic phonon dynamics as have been well…
In this note, I suggest that the beta-model used to fit the X-ray surface brightness profiles of extended sources, like groups and clusters of galaxies, has to be corrected when the counts are collected in a wide energy band comparable to…
The greybody factor of massless, uncharged scalar fields is studied in the background of cylindrically symmetric spacetimes, in the low-energy approximation. We discuss two cases. In the first case we derive analytical expression for the…
A cosmological model is proposed for the current Universe consisted of non-interacting baryonic matter and interacting dark components. The dark energy and dark matter are coupled through their effective barotropic indexes, which are…
Recently, some very strong correlations between the distribution of dark matter and baryons (the dark matter-baryon relations) in galaxies with very different morphologies, masses, sizes, and gas fractions have been obtained. Some models…
We study the reflection coefficient, the transmission coefficient and the greybody factors for black holes with topologically non trivial transverse sections in 4 and d-dimensions, in the limit of low energy. Considering a massive scalar…
A model of compact object coupled to inhomogeneous anisotropic dark energy is studied. It is assumed a variable dark energy that suffers a phase transition at a critical density. The anisotropic Lambda-Tolman-Oppenheimer-Volkoff equations…
In this paper, we have studied an interacting dark energy model. We have assumed the gravitational interaction between the matter fields i.e. between barotropic fluid and the dark energy. The dark energy evolution within the framework of…
An important question in polariton chemistry is whether reacting molecules are in thermal equilibrium with their surroundings. If not, can experimental changes observed in reaction rates of molecules in a cavity (even without optical…
Astrometry -- the precise measurement of positions and motions of celestial objects -- has emerged as a promising avenue for characterizing the dark matter population in our Galaxy. By leveraging recent advances in simulation-based…
In this paper we compute the corrections to the black-body force (BBF) potential due to spacetime geometry and topology. This recently discovered attractive force on neutral atoms is caused by the thermal radiation emitted from black bodies…
Thermodynamical properties of nuclear matter are studied in the framework of an effective many-body field theory at finite temperature, considering the Sommerfeld approximation. We perform the calculations by using the nonlinear Boguta and…
In today's modern wide-field galaxy surveys, there is the necessity for parametric surface brightness decomposition codes characterised by accuracy, small degree of user intervention, and high degree of parallelisation. We try to address…
Recent work has suggested that the fraction of obscured AGN declines with increasing luminosity, but it has been difficult to quantify this trend. Here, we attempt to measure this fraction as a function of luminosity by studying the ratio…
We investigate the possibility of dark matter being a pure geometrical effect, rather than a particle or a compact object, by exploring a specific modified gravity model: mimetic dark matter. We present an alternative formulation of the…
The field of asteroid thermophysical modeling has experienced an extraordinary growth in the last ten years, as new thermal infrared data became available for hundreds of thousands of asteroids. The infrared emission of asteroids depends on…