The curvature effect on the gravitational collapse of interacting and non-interacting combination of dark matter and dark energy

2020 ◽  
Vol 35 (17) ◽  
pp. 2050078
Author(s):  
S. Z. Abbas ◽  
H. H. Shah ◽  
W. Chammam ◽  
H. Sun ◽  
Wasim Ul Haq ◽  
...  

The study of gravitational collapse is a very interesting phenomena in general relativistic astrophysics. Here, in this study we investigated the gravitational collapse of a spherically symmetric core of a star, constituted of dark matter (DM) ([Formula: see text]), in dark energy (DE) ([Formula: see text]) background. It was investigated that gravitational collapse of interacting and noninteracting combination of DM and DE yields BH formation. In this work, our main aim is to examine the effect of space–time curvature [Formula: see text] on the gravitational collapse of interacting and noninteracting combination of dark matter and DE. We achieve the visible influence of curvature on gravitational collapse analytically and interpret the results graphically.

2017 ◽  
Vol 26 (13) ◽  
pp. 1750142 ◽  
Author(s):  
Hasrat Hussain Shah ◽  
Quaid Iqbal

In this work, we study the gravitational collapsing process of a spherically symmetric star constitute of Dark Matter (DM), [Formula: see text], and Dark Energy (DE) [Formula: see text]. In this model, we use anisotropic pressure with Equation of State (EoS) [Formula: see text] and [Formula: see text], [Formula: see text]. It reveals that gravitational collapse of DM and DE with interaction leads to the formation of the black hole. When [Formula: see text] (phantoms), dust and phantoms could be ejected from the death of white hole. This emitted matter again undergoes to collapsing process and becomes the black hole. This study gives the generalization for isotropy of pressure in the fluid to anisotropy when there will be interaction between DM and DE.


2018 ◽  
Vol 27 (03) ◽  
pp. 1850020 ◽  
Author(s):  
Hasrat Hussain Shah

In the last three to four decades, various programs have been studied in order to investigate the final fate of gravitational collapse of massive astronomical objects. In the theoretical context, Black Holes (BHs) are the consequence of final stage of the gravitational collapse. In this work, we investigated the gravitational collapse process of a spherically symmetric star constituted of dark matter (DM), [Formula: see text], and Dark Energy (DE), [Formula: see text] in the context of the brane-world scenario. In our model, we discussed the anisotropy of the pressure in a fluid with Equation of State (EoS) [Formula: see text] and [Formula: see text], [Formula: see text]. We briefly discussed various cases of gravitational collapse and it is found that BH can be formed by the gravitational collapse in brane-world regime while in some cases there is only a naked singularity at their end state.


2018 ◽  
Vol 33 (23) ◽  
pp. 1850132 ◽  
Author(s):  
Hasrat Hussain Shah ◽  
Farook Rahaman

In the scenario of an optimal consideration that is, homogeneous and flat spacetime, we study the Black Hole (BH) formation from the gravitational collapse of a spherical symmetric clump of matter in the case of the specific Dark Matter (DM) model interacting with Dark Energy (DE) in the context of the brane world regime. This clump of matter constituted of DM, [Formula: see text] and DE, [Formula: see text]. In the present model, we consider anisotropic pressure in the energy–momentum tensor with a polytropic equation of state (EoS), [Formula: see text] and [Formula: see text], [Formula: see text]. Our results show that the gravitational collapse of an interacting combination of DM and DE leads to the formation of BH in the presence of brane tension. Recent work provides the generalization of isotropic pressure to an-isotropic pressure in the energy–momentum tensor for the specific interacting combination model of DM and DE in a brane world regime.


2019 ◽  
Vol 34 (29) ◽  
pp. 1950240 ◽  
Author(s):  
Syed Zaheer Abbas ◽  
Hasrat Hussain Shah ◽  
Huafei Sun ◽  
Farook Rahaman ◽  
Faizuddin Ahmed

Study of gravitational collapse and black hole formation has got much interest in recent years after gravitational waves detection from mergers of black hole binaries. Here, we studied the gravitational collapse of a spherically symmetric clump of matter, constituted of dust fluid, [Formula: see text], in a background of dark energy, [Formula: see text]. We investigate the curvature effect [Formula: see text] on the gravitational collapsing process. Gravitational collapsing process for two different cases is discussed i.e. collapse of dust cloud only and collapse of dark energy. We used equation of state [Formula: see text], [Formula: see text]. For dark energy case, we discuss the collapsing process and curvature effect for different parameter values of equation of state.


1976 ◽  
Vol 31 (11) ◽  
pp. 1271-1276 ◽  
Author(s):  
M. Heller ◽  
M. Reinhardt

Abstract After a general classification of meaningless questions in science we concentrate on empirically meaningless questions. Introducing the concepts of informationally connected, semiconnected and disconnected observers, a formalism for the analysis of the informational structure of space-time is developed. We discuss some problems of epistemological nature in cosmology and blade hole physics. A number of questions like "What was 'before' the initial singularity of the universe?" or "What is the fate of matter in gravitational collapse inside the event horizon?" turn out to be empirically meaningless. We also show that a "wormhole" does not violate causality for the set of informationally connected observers who do not enter it.


2011 ◽  
Vol 26 (28) ◽  
pp. 2135-2147 ◽  
Author(s):  
KANG ZHOU ◽  
ZHAN-YING YANG ◽  
DE-CHENG ZOU ◽  
RUI-HONG YUE

We explore the gravitational collapse of a spherically symmetric dust cloud in the Einstein–Gauss–Bonnet gravity without a cosmological constant, and obtain three families of LTB-like solutions. It is shown that the Gauss–Bonnet term has a profound influence on the nature of singularities, and the global structure of spacetime changes drastically from the analogous general relativistic case. Interestingly, the formation of a naked, massive and uncentral singularity, allowed in five-dimensional spacetime, is forbidden if D≥6. Moreover, such singularity is gravitational strong and a serious counterexample to CCH.


2014 ◽  
Vol 11 (06) ◽  
pp. 1450059 ◽  
Author(s):  
Stuart Marongwe

In a recently published paper called Nexus: A quantum theory of space-time, gravity and the quantum vacuum by the above author, a plausible self-consistent quantum theory of space-time, gravity and the quantum vacuum is provided. In this current paper the author focuses primarily on the graviton as described in Nexus as a solution to the enigmatic phenomena of Dark Energy and Dark Matter as well as includes corrections to the first paper.


Author(s):  
Rodney Bartlett

In 1982, MIT physicist Frank Wilczek predicted and named ANYONS, quasiparticles (particle-like formations) that are confined to 2 dimensions and were discovered in 2020. The name might come from Prof. Wilczek's lighthearted comment "anything goes". This article's main goal is to show that anyons could be another name for 1) virtual particles, 2) Mobius strips, and 3) figure-8 Klein bottles. Along the way, we'll see the picture painted by the article confirm that Einstein's dream of gravitational-electromagnetic unity fits in with anyons being Mobius strips. The topological hypothesis offers an explanation of dark matter and dark energy. We'll also have encounters with intergalactic travel and imaginary computers. They really could exist but are imaginary in the sense that they use imaginary time (as well as space-time warping).


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