30 citations · 105 across the 12 of their papers we have counts for
12 papers · 1 filter
Quasibound states of the Dirac field in Schwarzschild and Reissner-Nordström black hole backgrounds
Ciprian A. Sporea
In this paper, we study the existence of (quasi)bound states in two spacetime geometries describing Schwarzschild and Reissner-Nordström black holes. For obtaining this type of sta…
Scattering of quantum fields by a MOG Black Hole
Ciprian A. Sporea
This paper aims to investigate the scattering of fermions by spherically symmetric MOG black holes, which are a type of black holes encountered in scalar-tensor-vector modified gra…
Scattering of Dirac fermions by spherical massive bodies
Ion I. Cotaescu, Ciprian A. Sporea
The asymptotic form of Dirac spinors in the field of a Schwarzschild black hole is used for deriving analytically for the first time the phase shifts of the partial wave analysis o…
Fermion scattering by a class of Bardeen black holes
Ciprian A. Sporea
In this paper the scattering of fermions by a class of Bardeen black holes is investigated. After obtaining the scattering modes by solving the Dirac equation in this geometry, we…
A simple model for explaining Galaxy Rotation Curves
Aneta Wojnar, Ciprian A. Sporea, Andrzej Borowiec
A new simple expression for the circular velocity of spiral galaxies is proposed and tested against HI Nearby Galaxy Survey (THINGS) data set. Its accuracy is compared with the one…
Scattering of massless fermions by Schwarzschild and Reissner-Nordström black holes
Ciprian A. Sporea
In this paper we are studying the scattering of massless Dirac fermions by Schwarzschild and Reissner-Nordström black holes. This is done by applying the partial wave analysis to t…
Galaxy Rotation Curves via Conformal Factors
Ciprian A. Sporea, Andrzej Borowiec, Aneta Wojnar
We propose a new formula to explain circular velocity profiles of spiral galaxies obtained from the Starobinsky model in Palatini formalism. It is based on the assumption that the…
Low energy Greybody factors for fermions emitted by a Schwarzschild-de Sitter black hole
Ciprian A. Sporea, Andrzej Borowiec
In this paper we are discussing the problem of low-energy greybody factors for fermions emitted by a Schwarzschild-de Sitter black hole. In our study we are using the analytical me…
New modes for massive Dirac field in higher dimensional Black Holes
Ciprian A. Sporea
In this letter we derive new modes for massive Dirac field in the background of a higher-dimensional Schwarzschild black hole. We use in our approach the Cartesian gauge defined in…
Using Maple + GRTensorII in teaching basics of General Relativity and Cosmology
Ciprian A. Sporea, Dumitru N. Vulcanov
In this article we propose some Maple procedures, for teaching purposes, to study the basics of General Relativity (GR) and Cosmology. After presenting some features of GRTensorII,…
Partial wave analysis of the Dirac fermions scattered from Schwarzschild black holes
Ion I. Cotaescu, Cosmin Crucean, Ciprian A. Sporea
Asymptotic analytic solutions of the Dirac equation, giving the scattering modes (of the continuous energy spectrum, ) in Schwarzschild's chart and Cartesian gauge, are use…
Notes on f(R) Theories of Gravity
Ciprian A. Sporea
In this review paper we present some basic notions about f(R) theories of gravity and some simple cosmological models derived from it. We first make an introduction to General Rela…