10 research outputs found
Micro black holes in the laboratory
The possibility of creating microscopic black holes is one of the most exciting predictions
for the LHC, with potentially major consequences for our current understanding of
physics. We briefly review the theoretical motivation for micro black hole production,
and our understanding of their subsequent evolution. Recent work on modelling the
radiation from quantum-gravity-corrected black holes is also discussed
Production and evaporation of Planck scale black holes at the LHC
We review the phenomenology of mini black holes at colliders in light of the latest data from the LHC. By improving the conventional production cross-section, we show that the current non-observation of black hole signals can be explained in terms of quantum gravity effects. In the most optimistic case, black hole production could take place at a scale slightly above the LHC design energy. We also analyse possible new signatures of quantum-corrected Planck-scale black holes: in contrast to the semiclassical scenario the emission would take place in terms of soft particles mostly on the brane
Spinning Loop Black Holes
In this paper we construct four Kerr-like spacetimes starting from the loop
black hole Schwarzschild solutions (LBH) and applying the Newman-Janis
transformation. In previous papers the Schwarzschild LBH was obtained replacing
the Ashtekar connection with holonomies on a particular graph in a
minisuperspace approximation which describes the black hole interior. Starting
from this solution, we use a Newman-Janis transformation and we specialize to
two different and natural complexifications inspired from the complexifications
of the Schwarzschild and Reissner-Nordstrom metrics. We show explicitly that
the space-times obtained in this way are singularity free and thus there are no
naked singularities. We show that the transformation move, if any, the
causality violating regions of the Kerr metric far from r=0. We study the
space-time structure with particular attention to the horizons shape. We
conclude the paper with a discussion on a regular Reissner-Nordstrom black hole
derived from the Schwarzschild LBH and then applying again the Newmann-Janis
transformation.Comment: 18 pages, 18 figure
TeV Mini Black Hole Decay at Future Colliders
It is generally believed that mini black holes decay by emitting elementary
particles with a black body energy spectrum. The original calculation lead to
the conclusion that about the 90% of the black hole mass is radiated away in
the form of photons, neutrinos and light leptons, mainly electrons and muons.
With the advent of String Theory, such a scenario must be updated by including
new effects coming from the stringy nature of particles and interactions.By
taking for granted that black holes can be produced in hadronic collisions,
then their decay must take into account that: (i) we live in a D3-Brane
embedded into an higher dimensional bulk spacetime; (ii) fundamental
interactions, including gravity, are unified at TeV energy scale. Thus, the
formal description of the Hawking radiation mechanism has to be extended to the
case of more than four spacetime dimensions and include the presence of
D-branes. Furthermore, unification of fundamental interactions at an energy
scale many order of magnitude lower than the Planck energy implies that any
kind of fundamental particle, not only leptons, is expected to be emitted. A
detailed understanding of the new scenario is instrumental for optimal tuning
of detectors at future colliders, where, hopefully, this exciting new physics
will be tested. In this article we review higher dimensional black hole decay,
considering not only the emission of particles according to Hawking mechanism,
but also their near horizon QED/QCD interactions. The ultimate motivation is to
build up a phenomenologically reliable scenario, allowing a clear experimental
signature of the event.Comment: 22 pages, 9 figures, 4 tables; ``quick review'' for Class. and
Quantum Gra
Hawking emission from quantum gravity black holes
We address the issue of modelling quantum gravity effects in the evaporation
of higher dimensional black holes in order to go beyond the usual
semi-classical approximation. After reviewing the existing six families of
quantum gravity corrected black hole geometries, we focus our work on
non-commutative geometry inspired black holes, which encode model independent
characteristics, are unaffected by the quantum back reaction and have an
analytical form compact enough for numerical simulations. We consider the
higher dimensional, spherically symmetric case and we proceed with a complete
analysis of the brane/bulk emission for scalar fields. The key feature which
makes the evaporation of non-commutative black holes so peculiar is the
possibility of having a maximum temperature. Contrary to what happens with
classical Schwarzschild black holes, the emission is dominated by low frequency
field modes on the brane. This is a distinctive and potentially testable
signature which might disclose further features about the nature of quantum
gravity.Comment: 36 pages, 18 figures, v2: updated reference list, minor corrections,
version matching that published on JHE
Renormalization group improved black hole space-time in large extra dimensions
By taking into account a running of the gravitational coupling constant with
an ultra violet fixed point, an improvement of classical black hole space-times
in extra dimensions is studied. It is found that the thermodynamic properties
in this framework allow for an effective description of the black hole
evaporation process. Phenomenological consequences of this approach are
discussed and the LHC discovery potential is estimated.Comment: 13 pages, 6 figure
Minimum black hole mass from colliding Gaussian packets
We study the formation of a black hole in the collision of two Gaussian
packets. Rather than following their dynamical evolution in details, we assume
a horizon forms when the mass function for the two packets becomes larger than
half the flat areal radius, as it would occur in a spherically symmetric
geometry. This simple approximation allows us to determine the existence of a
minimum black hole mass solely related to the width of the packets. We then
comment on the possible physical implications, both in classical and quantum
physics, and models with extra spatial dimensions.Comment: 11 pages, 4 figure
Physics on Smallest Scales - an Introduction to Minimal Length Phenomenology
Many modern theories which try to unify gravity with the Standard Model of
particle physics, as e.g. string theory, propose two key modifications to the
commonly known physical theories: i) the existence of additional space
dimensions; ii) the existence of a minimal length distance or maximal
resolution. While extra dimensions have received a wide coverage in
publications over the last ten years (especially due to the prediction of micro
black hole production at the LHC), the phenomenology of models with a minimal
length is still less investigated. In a summer study project for bachelor
students in 2010 we have explored some phenomenological implications of the
potential existence of a minimal length. In this paper we review the idea and
formalism of a quantum gravity induced minimal length in the generalised
uncertainty principle framework as well as in the coherent state approach to
non-commutative geometry. These approaches are effective models which can make
model-independent predictions for experiments and are ideally suited for
phenomenological studies. Pedagogical examples are provided to grasp the
effects of a quantum gravity induced minimal length. This article is intended
for graduate students and non-specialists interested in quantum gravity.Comment: v1: 10 pages, 3 figures, paper originated by a summer study for
bachelor students at the University of Frankfurt; v2: 11 pages, 3 figures,
minor modifications, version accepted for publication on European Journal of
Physic