scholarly journals SCHWARZSCHILD–de SITTER BLACK HOLES IN (4 + 1)-DIMENSIONAL BULK

2007 ◽  
Vol 22 (04) ◽  
pp. 289-296
Author(s):  
METİN ARIK ◽  
DİLEK ÇİFTCİ

We construct a static solution for (4 + 1)-dimensional bulk such that the (3 + 1)-dimensional world has a linear warp factor and describes the Schwarzschild–dS4 black hole. For m = 0 this four-dimensional universe and Friedmann–Robertson–Walker universe are related with an explicit coordinate transformation. We emphasize that for linear warp factors the effect of bulk on the brane world shows up as the dS4 background which is favored by the big bang cosmology.

Author(s):  
F. Melia ◽  
T. M. McClintock

The recent discovery of the ultraluminous quasar SDSS J010013.02+280225.8 at redshift 6.3 has exacerbated the time compression problem implied by the appearance of supermassive black holes only approximately 900 Myr after the big bang, and only approximately 500 Myr beyond the formation of Pop II and III stars. Aside from heralding the onset of cosmic re-ionization, these first and second generation stars could have reasonably produced the approximately 5–20  M ⊙ seeds that eventually grew into z approximately 6–7 quasars. But this process would have taken approximately 900 Myr, a timeline that appears to be at odds with the predictions of Λ CDM without an anomalously high accretion rate, or some exotic creation of approximately 10 5   M ⊙ seeds. There is no evidence of either of these happening in the local Universe. In this paper, we show that a much simpler, more elegant solution to the supermassive black hole anomaly is instead to view this process using the age–redshift relation predicted by the R h = ct Universe, an Friedmann–Robertson–Walker (FRW) cosmology with zero active mass. In this context, cosmic re-ionization lasted from t approximately 883 Myr to approximately 2 Gyr ( 6 ≲ z ≲ 15 ), so approximately 5–20  M ⊙ black hole seeds formed shortly after re-ionization had begun, would have evolved into approximately 10 10   M ⊙ quasars by z approximately 6–7 simply via the standard Eddington-limited accretion rate. The consistency of these observations with the age–redshift relationship predicted by R h = ct supports the existence of dark energy; but not in the form of a cosmological constant.


Author(s):  
Jae-Kwang Hwang

The origins of the stellar mass neutron black holes and supermassive dark matter black holes without the singularities are reported based on the 4-D Euclidean space. The neutron black holes with the mass of mBH = 5 – 15 msun are made by the 6-quark merged states (N6q) of two neutrons with the mass (m(N6q) = 10 m(n)) of 9.4 GeV/c2 that gives the black hole mass gap of mBH = 3 – 5 msun. Also, the supermassive black holes with the mass of mSMBH = 106 – 1011 msun are made by the merged 3-D states (J(B1B2B3)3 particles) of the dark matters. The supermassive black hole at the center of the Milky way galaxy has the mass of mSMBH = 4.1 106 msun that is consistent with mSMBH = 2.08 - 6.23 106 msun calculated from the 3-D states (J(B1B2B3)3 particles) of the dark matters with the mass of m(J) = 1.95 1015 eV/c2. In other words, this supports the existence of the B1, B2 and B3 dark matters with the proposed masses. The first dark matter black hole (primary black hole) was created at the big bang. This first dark matter black hole decayed to the supermassive dark matter black holes through the secondary dark matter black holes that are explained by the merged states of the J(B1B2B3)3 particles. The universe evolution is closely connected to the decaying process of the dark matter black holes since the big bang. The dark matter cloud states are proposed at the intermediate mass black hole range of mIMBH = 102 – 105 msun. This can explain why the dark matter black holes are not observed at the intermediate mass black hole range of mIMBH = 102 – 105 msun.


Author(s):  
Jae-Kwang Hwang

The origins of the stellar mass neutron black holes and supermassive dark matter black holes without the singularities are reported based on the 4-D Euclidean space. The neutron black holes with the mass of mBH = 5 – 15 msun are made by the 6-quark merged states (N6q) of two neutrons with the mass (m(N6q) = 10 m(n)) of 9.4 GeV/c2 that gives the black hole mass gap of mBH = 3 – 5 msun. Also, the supermassive black holes with the mass of mSMBH = 106 – 1011 msun are made by the merged 3-D states (J(B1B2B3)3 particles) of the dark matters. The supermassive black hole at the center of the Milky way galaxy has the mass of mSMBH = 4.1 106 msun that is consistent with mSMBH = 2.08 - 6.23 106 msun calculated from the 3-D states (J(B1B2B3)3 particles) of the dark matters with the mass of m(J) = 1.95 1015 eV/c2. In other words, this supports the existence of the B1, B2 and B3 dark matters with the proposed masses. The first dark matter black hole (primary black hole) was created at the big bang. This first dark matter black hole decayed to the supermassive dark matter black holes through the secondary dark matter black holes that are explained by the merged states of the J(B1B2B3)3 particles. The universe evolution is closely connected to the decaying process of the dark matter black holes since the big bang. The dark matter cloud states are proposed at the intermediate mass black hole range of mIMBH = 102 – 105 msun. This can explain why the dark matter black holes are not observed at the intermediate mass black hole range of mIMBH = 102 – 105 msun.


Science ◽  
2017 ◽  
Vol 357 (6358) ◽  
pp. 1375-1378 ◽  
Author(s):  
Shingo Hirano ◽  
Takashi Hosokawa ◽  
Naoki Yoshida ◽  
Rolf Kuiper

The origin of super-massive black holes in the early universe remains poorly understood. Gravitational collapse of a massive primordial gas cloud is a promising initial process, but theoretical studies have difficulty growing the black hole fast enough. We report numerical simulations of early black hole formation starting from realistic cosmological conditions. Supersonic gas motions left over from the Big Bang prevent early gas cloud formation until rapid gas condensation is triggered in a protogalactic halo. A protostar is formed in the dense, turbulent gas cloud, and it grows by sporadic mass accretion until it acquires 34,000 solar masses. The massive star ends its life with a catastrophic collapse to leave a black hole—a promising seed for the formation of a monstrous black hole.


2018 ◽  
Vol 33 (03) ◽  
pp. 1850024
Author(s):  
Biplab Paik

Being inspired by the Eddington’s idea, along with other auxiliary arguments, it is unveiled that there exist regimes of a black hole that would prohibit accretion of ordinary energy. In explicit words, there exists a lower bound to black hole mass below which matter accretion process does not run for black holes. Not merely the baryonic matter, but, in regimes, also the massless photons could get prohibited from rushing into a black hole. However, unlike the baryon accretion abandoned black hole regime, the mass-regime of a black hole prohibiting accretion of radiation could vary along with its ambient temperature. For example, we discuss that earlier to [Formula: see text] s after the big-bang, as the cosmological temperature of the Universe grew above [Formula: see text] K, the mass range of black hole designating the radiation accretion abandoned regime, had to be in varying state being connected with the instantaneous age of the evolving Universe by an “one half” power law. It happens to be a fact that a black hole holding regimes prohibiting accretion of energy is gigantic by its size in comparison to the Planck length-scale. Hence the emergence of these regimes demands mini black holes for not being viable as profound suckers of energy. Consideration of accretion abandoned regimes could be crucial for constraining or judging the evolution of primordial black holes over the age of the Universe.


2014 ◽  
Vol 11 (05) ◽  
pp. 1450047 ◽  
Author(s):  
A. Belhaj ◽  
M. Chabab ◽  
H. El Moumni ◽  
M. B. Sedra ◽  
A. Segui

Inspired from the inflation brane world cosmology, we study the thermodynamics of a black hole solution in two-dimensional dilaton gravity with an arctangent potential background. We first derive the two-dimensional black hole geometry, then we examine its asymptotic behaviors. More precisely, we find that such behaviors exhibit properties appearing in some known cases including the anti-de Sitter and the Schwarzschild black holes. Using the complex path method, we compute the Hawking radiation. The entropy function can be related to the value of the potential at the horizon.


2020 ◽  
Vol 80 (7) ◽  
Author(s):  
P. Betzios ◽  
O. Papadoulaki

Abstract Motivated by the holographic self-tuning proposal of the cosmological constant, we generalize and study the cosmology of brane-worlds embedded in a higher-dimensional bulk black hole geometry. We describe the equations and matching conditions in the case of flat, spherical and hyperbolic slicing of the bulk geometry and find the conditions for the existence of a static solution. We solve the equations that govern dynamical geometries in the probe brane limit and we describe in detail the resulting brane-world cosmologies. Of particular interest are the properties of solutions when the brane-world approaches the black hole horizon. In this case the geometry induced on the brane is that of de Sitter, whose entropy and temperature is related to those of the higher dimensional bulk black hole.


2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Tomas Andrade ◽  
Christiana Pantelidou ◽  
Julian Sonner ◽  
Benjamin Withers

Abstract General relativity governs the nonlinear dynamics of spacetime, including black holes and their event horizons. We demonstrate that forced black hole horizons exhibit statistically steady turbulent spacetime dynamics consistent with Kolmogorov’s theory of 1941. As a proof of principle we focus on black holes in asymptotically anti-de Sitter spacetimes in a large number of dimensions, where greater analytic control is gained. We focus on cases where the effective horizon dynamics is restricted to 2+1 dimensions. We also demonstrate that tidal deformations of the horizon induce turbulent dynamics. When set in motion relative to the horizon a deformation develops a turbulent spacetime wake, indicating that turbulent spacetime dynamics may play a role in binary mergers and other strong-field phenomena.


2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Mehrdad Mirbabayi

Abstract We propose a Euclidean preparation of an asymptotically AdS2 spacetime that contains an inflating dS2 bubble. The setup can be embedded in a four dimensional theory with a Minkowski vacuum and a false vacuum. AdS2 approximates the near horizon geometry of a two-sided near-extremal Reissner-Nordström black hole, and the two sides can connect to the same Minkowski asymptotics to form a topologically nontrivial worm- hole geometry. Likewise, in the false vacuum the near-horizon geometry of near-extremal black holes is approximately dS2 times 2-sphere. We interpret the Euclidean solution as describing the decay of an excitation inside the wormhole to a false vacuum bubble. The result is an inflating region inside a non-traversable asymptotically Minkowski wormhole.


2004 ◽  
Vol 01 (03) ◽  
pp. 429-443
Author(s):  
JOEL SMOLLER ◽  
BLAKE TEMPLE

We derive and analyze the equations that extend the results in [20,21] to the case of non-critical expansion k≠0. By an asymptotic argument we show that the equation of state [Formula: see text] plays the same distinguished role in the analysis when k≠0 as it does when k=0: only for this equation of state does the shock emerge from the Big Bang at a finite nonzero speed — the speed of light. We also obtain a simple closed system that extends the case [Formula: see text] considered in [20,21] to the case of a general positive, increasing, convex equation of state p=p(ρ).


Sign in / Sign up

Export Citation Format

Share Document