Related papers: Properties of blueshifted light rays in quasispher…

This work discusses observational evidences of quantum effects on geometry in a black hole (BH) astrophysical context. We study properties of a family of loop quantum corrected regular BH solutions and their horizons, focusing on the…

We demonstrate the redshift-evolution of the spectral profile of H i Lyman-alpha (Ly{\alpha}) emission from star-forming galaxies. In this first study we pay special attention to the contribution of blueshifted emission. At redshift z =…

We have utilized the largest sample of $\gamma$-ray selected Fermi flat-spectrum radio quasars (FSRQs) ever used (519 sources) to construct the luminosity function and its evolution through the cosmic history. In addition to spanning large…

We study the properties and behaviour of the quasi-pseudospherical and quasi-planar Szekeres models, obtain the regularity conditions, and analyse their consequences. The quantities associated with "radius" and "mass" in the quasi-spherical…

Some quasi-thermal (QT) dominated gamma-ray bursts (GRBs) could be well described by a multi-color blackbody (BB) function or a combined model of BB plus non-thermal (NT) component. In this analysis, two QT radiation-dominated bursts with…

The structure and kinematics of the broad line region (BLR) in quasars are still not well established. One popular BLR model is the disk-wind model that offers a geometric unification of a quasar based on the angle of viewing. We construct…

For the sample from Ge et al. of 87 low-$z$ Palomar--Green (PG) quasi-stellar objects (QSOs) and 130 high-$z$ QSOs ($0<z<5$) with $\hb$-based single-epoch supermassive black hole (SMBH) masses, we performed a uniform decomposition of the…

We study the cosmic microwave background (CMB) anisotropy due to spherically symmetric nonlinear structures in flat universes with dust and a cosmological constant. By modeling a time-evolving spherical compensated void/lump by…

This paper investigates the characteristics of quasinormal modes (QNMs) of static, spherically symmetric black holes under the combined influence of spontaneous Lorentz symmetry breaking (LSB) induced by the Kalb-Ramond (KR) field and…

The intriguing observations of Swift/BAT X-ray flash XRF 060218 and the BATSE-BeppoSAX gamma-ray burst GRB 980425, both with much lower luminosity and redshift compared to other observed bursts, naturally lead to the question of how these…

In this catalog, we present the results of a systematic study of gamma-ray bursts (GRBs) with reliable redshift estimates detected in the triggered mode of the Konus-Wind (KW) experiment during the period from 1997 February to 2016 June.…

The Cosmic Blackbody Background Radiation pervades the entire Universe, and so falls into every astrophysical black hole. The blueshift of the infalling photons, measured by a static observer, is infinite at the event horizon. This raises a…

(I) We observed eight Seyfert~2s and two X--ray--weak Seyfert~1/QSOs with the ROSAT PSPC, and one Seyfert~2 with the ROSAT HRI. These targets were selected from the Extended 12\um\ Galaxy Sample. (II) Both Seyfert~1/QSOs vary by factors of…

Gamma-ray bursts (GRBs), among the most compelling astrophysical phenomena, are potential candidates for exploring the evolution of energy distribution among magnetic fields and particles through multiwavelength observations. The fraction…

The notion of an apparent horizon (AH) in a collapsing object can be carried over from the Lema\^{\i}tre -- Tolman (L--T) to the quasispherical Szekeres models in three ways: 1. Literally by the definition -- the AH is the boundary of the…

We investigated the rest frame spectral lags of two complete samples of bright long (50) and short (6) gamma-ray bursts (GRB) detected by Swift. We analysed the Swift/BAT data through a discrete cross-correlation function (CCF) fitted with…

In this work, we restudy the dependence of luminosity function and event rates for different gamma-ray burst samples on the criteria of sample selection and threshold effect. To compare with many previous studies, we have chosen two samples…

We introduce a quasi-local integral functional and scalar quasi-local variables to examine a wide class of spherically symmetric inhomogeneous spacetimes that generalize the Lemaitre-Tolman-Bondi (LTB) dust solutions ("LTB" spacetimes). By…

In this paper, we explore a deformed Schwarzschild black hole (BH) within a loop quantum gravity (LQG) framework incorporating both a quintessence field (QF) and a cloud of strings (CS), aiming to understand how these exotic fields…

Several authors have previously shown that Gpc-scale void based on the spherically symmetric LTB model can provide a good fit to certain cosmological data, including the SNIa data, but it is only consistent with the observed CMB dipole if…