Related papers: Limits on New Physics from Black Holes
Novel bound states are obtained for manifolds with singular potentials. These singular potentials require proper boundary conditions across boundaries. The number of bound states match nicely with what we would expect for black holes. Also…
In models with large extra dimensions, where the fundamental gravity scale can be in the electroweak range, gravitational effects in particle physics may be noticeable even at relatively low energies. In this paper, we perform simple…
We give simple and general explanation to the effect of unbound acceleration of particles by black holes. It is related to the fact that the scalar product of a timelike vector of the four-velocity of an ingoing particle and the lightlike…
Black holes are the elementary particles of gravity, the final state of sufficiently massive stars and of energetic collisions. With a forty-year long history, black hole physics is a fully-blossomed field which promises to embrace several…
It has been suggested that maximally spinning black holes can serve as particle accelerators, reaching arbitrarily high center-of-mass energies. Despite several objections regarding the practical achievability of such high energies, and…
Black holes monopolize nowadays the center stage of fundamental physics. Yet, they are poorly understood objects. Notwithstanding, from their generic properties, one can infer important clues to what a fundamental theory, a theory that…
The origin of observed extremely high energy cosmic rays remains an astrophysical enigma. We show that a single evaporating primordial black hole should produce 8.5*10^14 particles over a 10^20 eV threshold. This emission results from…
A cosmological scenario which explains the values of the parameters of the standard models of elementary particle physics and cosmology is discussed. In this scenario these parameters are set by a process analogous to natural selection…
The probability of a charged particle production by the electric field of a charged black hole depends essentially on the particle energy. This probability is found in the nonrelativistic and ultrarelativistic limits. The range of values…
The formation and semi-classical evaporation of two-dimensional black holes is studied in an exactly solvable model. Above a certain threshold energy flux, collapsing matter forms a singularity inside an apparent horizon. As the black hole…
It has been argued that neutrinos originating from ultra-high energy cosmic rays produce black holes deep in the atmosphere in models with TeV-scale quantum gravity. Such black holes would initiate quasi-horizontal showers of particles far…
We study the evolution of light spectator fields in an asymmetric polynomial potential. During inflation, stochastic fluctuations displace the spectator field from the global minimum of its potential, populating the false vacuum state and…
We study the effect of primordial black holes on the classical rate of nucleation of AdS regions within the standard electroweak vacuum. We find that the energy barrier for transitions to the new vacuum, which characterizes the exponential…
This talk reviews our recent work showing how tiny black holes can act as nucleation sites for the decay of the metastable Higgs vacuum. We start by discussing the formation of thin wall bubbles of true vacuum inside a false vacuum, and…
The new, rapidly developing field of theoretical research --- studies of dark energy interacting with black holes (and, in particular, accreting onto black holes) --- is reviewed. The term `dark energy' is meant to cover a wide range of…
The quantum genesis of Hawking radiation is a long-standing puzzle in black hole physics. Semi-classically one can argue that the spectrum of radiation emitted by a black hole look very much sparse unlike what is expected from a thermal…
We investigate the impact of neutrino emission via Hawking radiation from primordial black holes (PBHs) on the cosmological effective number of neutrino species, $N_{\mathrm{eff}}$, after neutrino decoupling. By comparing this effect with…
After reviewing the relation of entropy to information, I derive the entropy bound as applied to bounded weakly gravitating systems, and review the bound's applications to cosmology as well as its extensions to higher dimensions. I then…
The singularitiy inside a spherical charged black hole, coupled to a spherical, massless scalar field is studied numerically. The profile of the characteristic scalar field was taken to be a power of advanced time with an exponent…
Black holes are capable of reflection: there is a finite probability for any particle that approaches the event horizon to bounce back. The albedo of the black hole depends on its temperature and the energy of the incoming particle. The…