11,414 research outputs found
Black hole solution and strong gravitational lensing in Eddington-inspired Born-Infeld gravity
A new theory of gravity called Eddington-inspired Born-Infeld (EiBI) gravity
was recently proposed by Ba\~{n}ados and Ferreira. This theory leads to some
exciting new features, such as free of cosmological singularities. In this
paper, we first obtain a charged EiBI black hole solution with a nonvanishing
cosmological constant when the electromagnetic field is included in. Then based
on it, we study the strong gravitational lensing by the asymptotic flat charged
EiBI black hole. The strong deflection limit coefficients and observables are
shown to closely depend on the additional coupling parameter in the
EiBI gravity. It is found that, compared with the corresponding charged black
hole in general relativity, the positive coupling parameter will
shrink the black hole horizon and photon sphere. Moreover, the coupling
parameter will decrease the angular position and relative magnitudes of the
relativistic images, while increase the angular separation, which may shine new
light on testing such gravity theory in near future by the astronomical
instruments.Comment: 14 pages, 7 figures, 1 table. Two issues on the deflection angle and
photon sphere were corrected and clarifie
Non-classicalities via perturbing local unitary operations
We study the nonclassical correlations in a two-qubit state by the perturbing
local unitary operation method. We find that the definitions of various
non-classicalities including quantum discord (QD), measurement-induced
nonlocality (MIN) and so on usually do not have a unique definition when
expressed as the perturbation of local unitary operations, so a given
non-classicality can lead to different definitions of its dual
non-classicality. In addition, it is shown that QD and MIN are not the
corresponding dual expressions in a simple set of unitary operations, even
though they are in their original definitions. In addition, we also consider
the non-classicalities in general dimensional systems
Particle collisions in the lower dimensional rotating black hole space-time with the cosmological constant
In this paper, we study the effect of ultra-high energy collisions of two
particles with different energies near the horizon of a 2+1 dimensional BTZ
black hole (BSW effect). We find that the particle with the critical angular
momentum could exist inside the outer horizon of BTZ black hole regardless of
the particle energy. Therefore, for the non-extremal BTZ black hole, the BSW
process is possible on the inner horizon with the fine tuning of parameters
which are characterized by the motion of particle. While for the extremal BTZ
black hole, the particle with the critical angular momentum could only exist on
the degenerate horizon, and the BSW process could also happen there.Comment: 12 pages,3 figure
Noncommutativity as a Possible Origin of the Ultrahigh Energy Cosmic Ray and the TeV-photon Paradoxes
In this paper, we present a general modified dispersion relation derived from
q-deformed noncommutative theory and apply it to the ultrahigh energy cosmic
ray and the TeV-photon paradoxes--threshold anomalies. Our purpose is not only
trying to solve these puzzles by noncommutative theory but also to support
noncommutative theory through the coincidence of the region in the parameter
space for resolving the threshold anomalies with the one from the q-deformed
noncommutative theory.Comment: 9 pages, 1 figur
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