共查询到20条相似文献,搜索用时 593 毫秒
1.
Mubasher Jamil 《The European Physical Journal C - Particles and Fields》2009,62(3):609-614
In the classical relativistic regime, the accretion of phantom energy onto a black hole reduces the mass of the black hole.
In this context, we have investigated the evolution of a Schwarzschild black hole in the standard model of cosmology using
the phantom-like modified variable Chaplygin gas and the viscous generalized Chaplygin gas. The corresponding expressions
for accretion time scale and evolution of mass have been derived. Our results indicate that the mass of the black hole will
decrease if the accreting phantom Chaplygin gas violates the dominant energy condition and will increase in the opposite case.
Thus, our results are in agreement with the results of Babichev et al. who first proposed this scenario. 相似文献
2.
We investigate the effects of accretion of phantom energy onto primordial black holes. Since Hawking radiation and phantom
energy accretion contribute to a decrease of the mass of the black hole, the primordial black hole that would be expected to decay now due to the Hawking process would
decay earlier due to the inclusion of the phantom energy. Equivalently, to have the primordial black hole decay now it would have to be
more massive initially. We find that the effect of the phantom energy is substantial and the black holes decaying now would
be much more massive—over ten orders of magnitude! This effect will be relevant for determining the time of production and hence
the number of evaporating black holes expected in a universe accelerating due to phantom energy. 相似文献
3.
Solution for a stationary spherically symmetric accretion of the relativistic perfect fluid with an equation of state p(rho) onto the Schwarzschild black hole is presented. This solution is a generalization of Michel solution and applicable to the problem of dark energy accretion. It is shown that accretion of phantom energy is accompanied by the gradual decrease of the black hole mass. Masses of all black holes tend to zero in the phantom energy Universe approaching the Big Rip. 相似文献
4.
We consider the effect of accretion of radiation, matter and dark energy in the early universe on primordial black holes (PBH) in f(T) gravity. Due to the Hawking radiation, mass of the primordial black hole decreases. We show that for the phantom accretion inclusion with the Hawking evaporation, the mass of the PBH decreases faster whereas for the accretion of radiation, matter and quintessence together with Hawking evaporation, the mass increases in f(T) gravity. 相似文献
5.
In this paper, we have studied the accretion of phantom energy on a (2 + 1)-dimensional stationary Banados–Teitelboim–Zanelli
(BTZ) black hole. It has already been shown by Babichev et al. that for the accretion of phantom energy onto a Schwarzschild
black hole, the mass of black hole would decrease and the rate of change of mass would be dependent on the mass of the black
hole. However, in the case of (2 + 1)-dimensional BTZ black hole, the mass evolution due to phantom accretion is independent
of the mass of the black hole and is dependent only on the pressure and density of the phantom energy. We also study the generalized
second law of thermodynamics at the event horizon and construct a condition that puts an lower bound on the pressure of the
phantom energy. 相似文献
6.
ABBAS G. 《中国科学:物理学 力学 天文学(英文版)》2014,57(4):604-607
In this Letter,we examine the phantom energy accretion onto a Kehagias-Sfetsos black hole in Horava-Lifshitz gravity.To discuss the accretion process onto the black hole,the equations of phantom flow near the black hole have been derived.It is found that mass of the black hole decreases because of phantom accretion.We discuss the conditions for critical accretion.Graphically,it has been found that the critical accretion phenomena is possible for different values of parameters.The results for the Schwarzschild black hole can be recovered in the limiting case. 相似文献
7.
Sandip Dutta Ritabrata Biswas 《The European Physical Journal C - Particles and Fields》2017,77(10):717
This paper deals with the viscous accretion flow of a modified Chaplygin gas towards a black hole as the central gravitating object. A modified Chaplygin gas is a particular type of dark energy model which mimics of radiation era to phantom era depending on the different values of its parameters. We compare the dark energy accretion with the flow of adiabatic gas. An accretion disc flowing around a black hole is an example of a transonic flow. To construct the model, we consider three components of the Navier–Stokes equation, the equation of continuity and the modified Chaplygin gas equation of state. As a transonic flow passes through the sonic point, the velocity gradient being apparently singular there, it gives rise to two flow branches: one in-falling, the accretion and the other outgoing, the wind. We show that the wind curve is stronger and the wind speed reaches that of light at a finite distance from the black hole when dark energy is considered. Besides, if we increase the viscosity, the accretion disc is shortened in radius. These two processes acting together make the system deviate much from the adiabatic accretion case. It shows a weakening process for the accretion procedure by the work of the viscous system influencing both the angular momentum transport and the repulsive force of the modified Chaplygin gas. 相似文献
8.
We study the evolution of primordial black holes by considering present universe is no more matter dominated rather vacuum energy dominated. We also consider the accretion of radiation, matter and vacuum energy during respective dominance period. In this scenario, we found that radiation accretion efficiency should be less than 0.366 and accretion rate is much larger than previous analysis by Nayak et al. (2009) [1]. Thus here primordial black holes live longer than previous works Nayak and Singh (2011) [1]. Again matter accretion slightly increases the mass and lifetime of primordial black holes. However, the vacuum energy accretion is slightly complicated one, where accretion is possible only up to a critical time. If a primordial black hole lives beyond critical time, then its? lifespan increases due to vacuum energy accretion. But for presently evaporating primordial black holes, critical time comes much later than their evaporating time and thus vacuum energy could not affect those primordial black holes. 相似文献
9.
Xin Zhang 《The European Physical Journal C - Particles and Fields》2009,60(4):661-667
Infinitely cyclic cosmology is often frustrated by the black hole problem. It has been speculated that this obstacle in cyclic
cosmology can be removed by taking into account a peculiar cyclic model derived from loop quantum cosmology or the braneworld
scenario, in which phantom dark energy plays a crucial role. In this peculiar cyclic model, the mechanism of solving the black
hole problem is through tearing up black holes by phantom. However, using the theory of fluid accretion onto black holes,
we show in this paper that there exists another possibility: that black holes cannot be torn up by phantom in this cyclic
model. We discussed this possibility and showed that the masses of black holes might first decrease and then increase, through
phantom accretion onto black holes in the expanding stage of the cyclic universe. 相似文献
10.
We study the problem of standing shocks in viscous disc-like accretion flows around black holes. For the first time we parametrize such a flow with two physical constants, namely the specific angular momentum accreted by the black hole j and the energy quantity K. By providing the global dependence of shock formation in the j- K parameter space, we show that a significant parameter region can ensure solutions with Rankine-Hugoniot shocks; and that the possibilities of shock formation are the largest for inviscid flows, decreasing with increasing viscosity, and ceasing to exist for a strong enough viscosity. Our results support the view that the standing shock is an essential ingredient in black hole accretion discs and is a general phenomenon in astrophysics, and that there should be a continuous change from the properties of inviscid flows to those of viscous ones. 相似文献
11.
E. O. Babichev V. I. Dokuchaev Yu. N. Eroshenko 《Journal of Experimental and Theoretical Physics》2005,100(3):528-538
The stationary, spherically symmetric accretion of dark energy onto a Schwarzschild black hole is considered in terms of relativistic hydrodynamics. The approximation of an ideal fluid is used to model the dark energy. General expressions are derived for the accretion rate of an ideal fluid with an arbitrary equation of state p = p(ρ) onto a black hole. The black hole mass was found to decrease for the accretion of phantom energy. The accretion process is studied in detail for two dark energy models that admit an analytical solution: a model with a linear equation of state, p = α(ρ ? ρ0), and a Chaplygin gas. For one of the special cases of a linear equation of state, an analytical expression is derived for the accretion rate of dark energy onto a moving and rotating black hole. The masses of all black holes are shown to approach zero in cosmological models with phantom energy in which the Big Rip scenario is realized. 相似文献
12.
We have investigated the accretion of phantom energy onto a 5-dimensional extreme Einstein-Maxwell-Gauss-Bonnet (EMGB) black
hole. It is shown that the evolution of the EMGB black hole mass due to phantom energy accretion depends only on the pressure
and density of the phantom energy and not on the black hole mass. Further we study the generalized second law of thermodynamics
(GSL) at the event horizon and obtain a lower bound on the pressure of the phantom energy. 相似文献
13.
Mubasher Jamil Asghar Qadir Muneer Ahmad Rashid 《The European Physical Journal C - Particles and Fields》2008,58(2):325-329
In the classical relativistic regime, the accretion of phantom-like dark energy onto a stationary black hole reduces the mass
of the black hole. We have investigated the accretion of phantom energy onto a stationary charged black hole and have determined
the condition under which this accretion is possible. This condition restricts the mass-to-charge ratio in a narrow range.
This condition also challenges the validity of the cosmic-censorship conjecture since a naked singularity is eventually produced
due to accretion of phantom energy onto black hole. 相似文献
14.
Majumdar AS 《Physical review letters》2003,90(3):031303
We consider the evolution of primordial black holes formed during the high energy phase of the braneworld scenario. We show that the effect of accretion from the surrounding radiation bath is dominant compared to evaporation for such black holes. This feature lasts till the onset of matter (or black hole) domination of the total energy density which could occur either in the high energy phase or later. We find that the black hole evaporation times could be significantly large even for black holes with small initial mass to survive until several cosmologically interesting eras. 相似文献
15.
In this paper we deal with the accretion of phantom energy onto static spherically symmetric Bardeen black hole. It is shown that the mass of black hole reduces with the accretion of phantom energy. We compute accretion rate onto Bardeen black hole at critical point. Furthermore, we obtain the conditions at critical point, under which accretion is possible and also discuss certain relevant cases. Finally, we discuss the validity of generalized second law of thermodynamics at the event horizon of Bardeen black hole. 相似文献
16.
In this work, we study the evolution of primordial black holes within the context of Brans–Dicke theory by considering the
presence of a dark energy component with a super-negative equation of state, called phantom energy, as a background. Besides
Hawking evaporation, here we consider two types of accretion—radiation accretion and phantom energy accretion. We found that
radiation accretion increases the lifetime of primordial black holes whereas phantom accretion decreases the lifespan of primordial
black holes. Investigating the competition between the radiation accretion and phantom accretion, we found that there is an
instant during the matter-dominated era beyond which phantom accretion dominates radiation accretion. So the primordial black
holes which are formed in the later part of radiation-dominated era and in matter-dominated era are evaporated at a quicker
rate than by Hawking evaporation. But for presently evaporating primordial black holes, radiation accretion and Hawking evaporation
terms are dominant over the phantom accretion term and hence presently evaporating primordial black holes are not much affected
by phantom accretion. 相似文献
17.
A. S. Majumdar 《Pramana》2004,62(3):737-739
The Randall-Sundrum (RS-II) braneworld cosmological model with a fraction of the total energy density in primordial black
holes is considered. Due to their 5d geometry, these black holes undergo modified Hawking evaporation. It is shown that during
the high-energy regime, accretion from the surrounding radiation bath is dominant compared to evaporation. This effect increases
the mass of the black holes till the onset of matter (or black hole) domination of the total energy density. Thus black holes
with even very small initial masses could survive till several cosmologically interesting eras. 相似文献
18.
We study perturbations of black holes absorbing dark energy. Due to the accretion of dark energy, the black hole mass changes. We observe distinct perturbation behaviors for absorption of different forms of dark energy onto the black holes. This provides the possibility of extracting information whether dark energy lies above or below the cosmological constant boundary w=−1. In particular, we find in the late time tail analysis that, differently from the other dark energy models, the accretion of phantom energy exhibits a growing mode in the perturbation tail. The instability behavior found in this work is consistent with the Big Rip scenario, in which all of the bound objects are torn apart with the presence of the phantom dark energy. 相似文献
19.
S. Habib Mazharimousavi M. Halilsoy T. Tahamtan 《The European Physical Journal C - Particles and Fields》2012,72(3):1-9
In this work, we have studied accretion of the dark energies in new variable modified Chaplygin gas (NVMCG) and generalized cosmic Chaplygin gas (GCCG) models onto Schwarzschild and Kerr?CNewman black holes. We find the expression of the critical four velocity component which gradually decreases for the fluid flow towards the Schwarzschild as well as the Kerr?CNewman black hole. We also find the expression for the change of mass of the black hole in both cases. For the Kerr?CNewman black hole, which is rotating and charged, we calculate the specific angular momentum and total angular momentum. We showed that in both cases, due to accretion of dark energy, the mass of the black hole increases and angular momentum increases in the case of a Kerr?CNewman black hole. 相似文献
20.
The Babichev–Dokuchaev–Eroshenko model for the accretion of dark energy onto black holes has been extended to deal with black holes with non-static metrics. The possibility that for an asymptotic observer a black hole with large mass will rapidly increase and eventually engulf the Universe at a finite time in the future has been studied by using reasonable values for astronomical parameters. It is concluded that such a phenomenon is forbidden for all black holes in quintessential cosmological models. 相似文献