scholarly journals Cosmic cloaking of rich extra dimensions

2021 ◽  
Author(s):  
Aghil Alaee ◽  
Marcus Khuri ◽  
Hari Kunduri
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Extra Dimensions ◽  
Large Extra Dimensions ◽  
Dimensional Theory ◽  
Hoop Conjecture ◽  
Significant Size ◽  
The Universe ◽  
Lower Dimensional ◽  
Kaluza Klein

We present arguments that show why it is difficult to see rich extra dimensions in the universe. Conditions are found where significant size and variation of the extra dimensions in a Kaluza–Klein compactification lead to a black hole in the lower-dimensional theory. The idea is based on the hoop conjecture concerning black hole existence, as well as on the observation that dimensional reduction on macroscopically large, twisted, or highly dynamical extra dimensions contributes positively to the energy density in the lower-dimensional theory and can induce gravitational collapse. A threshold for the size is postulated on the order of [Formula: see text][Formula: see text]m, whereby extra dimensions of length above this level must lie inside black holes, thus cloaking them from the view of outside observers. The threshold depends on the size of the universe, leading to speculation that in the early stages of evolution truly macroscopic and large extra dimensions would have been visible.

scholarly journals SIGNATURES FOR BLACK HOLE PRODUCTION FROM HADRONIC OBSERVABLES AT THE LARGE HADRON COLLIDER

2007 ◽  
Vol 16 (03) ◽  
pp. 841-851 ◽  
Author(s):  
THOMAS J. HUMANIC ◽  
BENJAMIN KOCH ◽  
HORST STÖCKER
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Large Hadron Collider ◽  
Particle Tracking ◽  
Extra Dimensions ◽  
Large Extra Dimensions ◽  
Hadron Collider ◽  
Hierarchy Problem ◽  
Tracking Detector ◽  
Weak Forces

The concept of Large Extra Dimensions (LED) provides a way of solving the Hierarchy Problem which concerns the weakness of gravity compared with the strong and electro-weak forces. A consequence of LED is that miniature Black Holes (mini-BHs) may be produced at the Large Hadron Collider in p + p collisions. The present work uses the CHARYBDIS mini-BH generator code to simulate the hadronic signal which might be expected in a mid-rapidity particle tracking detector from the decay of these exotic objects if indeed they are produced. An estimate is also given for Pb + Pb collisions.

scholarly journals BLACK HOLES IN THEORIES WITH LARGE EXTRA DIMENSIONS: A REVIEW

2004 ◽  
Vol 19 (29) ◽  
pp. 4899-4951 ◽  
Author(s):  
PANAGIOTA KANTI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Hawking Radiation ◽  
Extra Dimensions ◽  
Large Extra Dimensions ◽  
Life Time ◽  
High Energy ◽  
High Energy Particle ◽  
Radiation Spectra ◽  
Black Hole Background

We start by reviewing the existing literature on the creation of black holes during high-energy particle collisions, both in the absence and in the presence of extra, compact, spacelike dimensions. Then, we discuss in detail the properties of the produced higher-dimensional black holes, namely the horizon radius, temperature and life-time, as well as the physics that governs the evaporation of these objects, through the emission of Hawking radiation. We first study the emission of visible Hawking radiation on the brane: we derive a master equation for the propagation of fields with arbitrary spin in the induced-on-the-brane black hole background, and we review all existing results in the literature for the emission of scalars, fermions and gauge bosons during the spin-down and Schwarzschild phases of the life of the black hole. Both analytical and numerical results for the graybody factors and radiation spectra are reviewed and exact results for the number and type of fields emitted on the brane as a function of the dimensionality of space–time are discussed. We finally study the emission of Hawking radiation in the bulk: graybody factors and radiation spectra are presented for the emission of scalar modes, and the ratio of the missing energy over the visible one is calculated for different values of the number of extra dimensions.

scholarly journals Natural cutoffs effect on charged rotating TeV-scale black hole thermodynamics

2016 ◽  
Vol 26 (06) ◽  
pp. 1750043
Author(s):  
M. J. Soleimani ◽  
N. Abbasvandi ◽  
G. Gopir ◽  
Zainol Abidin Ibrahim ◽  
Shahidan Radiman ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Momentum ◽  
Extra Dimensions ◽  
Large Extra Dimensions ◽  
Minimal Length ◽  
Black Hole Thermodynamics ◽  
Frame Dragging ◽  
Gravity Effects ◽  
Maximal Momentum

We study the thermodynamics of charged rotating black hole in large extra dimensions scenario where quantum gravity effects are taken into account. We consider the effects of minimal length, minimal momentum, and maximal momentum as natural cutoffs on the thermodynamics of charged rotating TeV-scale black holes. In this framework, the effect of the angular momentum and charge on the thermodynamics of the black hole are discussed. We focus also on frame dragging and Sagnac effect of the micro black holes.

scholarly journals BLACK HOLES REMNANTS IN EXTRA DIMENSIONS AND DARK MATTER

2006 ◽  
Vol 21 (23n24) ◽  
pp. 4979-4992 ◽  
Author(s):  
KOUROSH NOZARI ◽  
S. HAMID MEHDIPOUR
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Extra Dimensions ◽  
Large Extra Dimensions ◽  
Generalized Uncertainty Principle ◽  
Black Hole Thermodynamics ◽  
Gravitational Effects ◽  
Model Universe ◽  
Suitable Framework

Bekenstein–Hawking formalism of black hole thermodynamics should be modified to incorporate quantum gravitational effects. Generalized Uncertainty Principle (GUP) provides a suitable framework to perform such modifications. In this paper, we consider a general form of GUP to find black hole thermodynamics in a model universe with large extra dimensions. We will show that black holes radiate mainly in the four-dimensional brane. Existence of black holes remnants as a possible candidate for dark matter is discussed.

scholarly journals PROTON DECAY, BLACK HOLES, AND LARGE EXTRA DIMENSIONS

2001 ◽  
Vol 16 (13) ◽  
pp. 2399-2410 ◽  
Author(s):  
FRED C. ADAMS ◽  
GORDON L. KANE ◽  
MANASSE MBONYE ◽  
MALCOLM J. PERRY
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Lower Bound ◽  
Quantum Gravity ◽  
Extra Dimensions ◽  
Large Extra Dimensions ◽  
Proton Decay ◽  
Planck Mass ◽  
Proton Lifetime ◽  
Virtual Black Holes

We consider proton decay in theories that contain large extra dimensions. If virtual black hole states are allowed by the theory, as is generally the case, then proton decay can proceed via virtual black holes. The experimental limits on the proton lifetime place strong constraints on the quantum gravity scale M qg (the effective Planck mass). For most theories, this implies a lower bound of M qg >1016 GeV. The corresponding bound on the size of large extra dimensions is ℓ<106/n×10-30 cm, where n is the number of such dimensions. Regrettably, for most theories this limit rules out the possibility of observing large extra dimensions at accelerators or in millimeter scale gravity experiments. Conversely, proton decay could be dominated by virtual black holes, providing an experimental probe to study stringy quantum gravity physics.

scholarly journals Vacua and exact solutions in lower-D limits of EGB

2020 ◽  
Vol 80 (12) ◽  
Author(s):  
Liang Ma ◽  
H. Lü
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Exact Solutions ◽  
The Other ◽  
Reality Condition ◽  
Bonnet Gravity ◽  
Cosmological Solutions ◽  
Scalar Hair ◽  
Lower Dimensional ◽  
Kaluza Klein

AbstractWe consider the action principles that are the lower dimensional limits of the Einstein–Gauss–Bonnet gravity via the Kaluza–Klein route. We study the vacua and obtain some exact solutions. We find that the reality condition of the theories may select one vacuum over the other from the two vacua that typically arise in Einstein–Gauss–Bonnet gravity. We obtain exact black hole and cosmological solutions carrying scalar hair, including scalar hairy BTZ black holes with both mass and angular momentum turned on. We also discuss the holographic central charges in the asymptotic AdS backgrounds.

scholarly journals BLACK HOLE AND BRANE PRODUCTION IN TEV GRAVITY: A REVIEW

2003 ◽  
Vol 18 (11) ◽  
pp. 1843-1882 ◽  
Author(s):  
MARCO CAVAGLIÀ
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Extra Dimensions ◽  
Large Extra Dimensions ◽  
Center Of Mass ◽  
Cosmic Ray ◽  
High Energy ◽  
Mass Energy ◽  
Particle Collisions ◽  
Center Of Mass Energy

In models with large extra dimensions, particle collisions with center-of-mass energy larger than the fundamental gravitational scale can generate nonperturbative gravitational objects such as black holes and branes. The formation and the subsequent decay of these super-Planckian objects would be detectable in particle colliders and high energy cosmic ray detectors, and have interesting implications in cosmology and astrophysics. In this paper we present a review of black hole and brane production in TeV-scale gravity.

scholarly journals Uptunneling to de Sitter

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Mehrdad Mirbabayi
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
False Vacuum ◽  
De Sitter ◽  
Dimensional Theory ◽  
Hole Geometry ◽  
Horizon Geometry ◽  
Two Sides ◽  
Extremal Black Holes

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.

scholarly journals Black Holes in the Universe

1998 ◽  
Vol 11 (1) ◽  
pp. 28-41
Author(s):  
I.D. Novikov
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Neutron Stars ◽  
Supernova Explosions ◽  
The Universe

Some 30 years ago very few scientists thought that black holes may really exist. Attention focussed on the black hole hypothesis after neutron stars had been discovered. It was rather surprising that astrophysicists immediately ‘welcomed’ black holes. They found their place not only in the remnants of supernova explosions but also in the nuclei of galaxies and quasars.

scholarly journals Symmetry and the Arrow of Time in Theoretical Black Hole Astrophysics

2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
David Garofalo
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Active Galactic Nuclei ◽  
Accretion Disks ◽  
Time Reversal ◽  
Large Scale ◽  
Galactic Nuclei ◽  
Arrow Of Time ◽  
Time Symmetry ◽  
The Universe

While the basic laws of physics seem time-reversal invariant, our understanding of the apparent irreversibility of the macroscopic world is well grounded in the notion of entropy. Because astrophysics deals with the largest structures in the Universe, one expects evidence there for the most pronounced entropic arrow of time. However, in recent theoretical astrophysics work it appears possible to identify constructs with time-reversal symmetry, which is puzzling in the large-scale realm especially because it involves the engines of powerful outflows in active galactic nuclei which deal with macroscopic constituents such as accretion disks, magnetic fields, and black holes. Nonetheless, the underlying theoretical structure from which this accreting black hole framework emerges displays a time-symmetric harmonic behavior, a feature reminiscent of basic and simple laws of physics. While we may expect such behavior for classical black holes due to their simplicity, manifestations of such symmetry on the scale of galaxies, instead, surprise. In fact, we identify a parallel between the astrophysical tug-of-war between accretion disks and jets in this model and the time symmetry-breaking of a simple overdamped harmonic oscillator. The validity of these theoretical ideas in combination with this unexpected parallel suggests that black holes are more influential in astrophysics than currently recognized and that black hole astrophysics is a more fundamental discipline.

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