18923559
Cosmological production of charged black hole pairs.
We investigate the pair creation of charged black holes in a back- ground with a positive cosmological constant. We consider C metrics with a cosmological constant, and show that the conical singularities in the metric only disappear when it reduces to the Reissner-Nordstrom de Sitter metric. We construct an instanton describing the pair pro- duction of extreme black holes and an instanton describing the pair production of non-extreme black holes from the Reissner-Nordstrom de Sitter metric, and calculate their actions. There are a number of striking similarities between these instantons and the Ernst instantons, which describe pair production in a background electromagnetic field. We also observe that the type I instanton in the ordinary C metric with zero cosmological constant is actually the Reissner-Nordstrom solution.
119405301
Infinite Blueshift of Charged Null Particles
We demonstrate that charged null particles can be infinitely blue\-shifted in a Kerr-Newman spacetime. The surface of infinite blueshift can be outside of the ergosphere in a Kerr-Newman spacetime, and outside of the outer event horizon for a Reissner-Nordstrom spacetime. Implications for extensions of the standard model which incorporate charged neutrinos are discussed.
461049
Testing the Equivalence Principle in the Quantum Regime
We consider possible tests of the Einstein Equivalence Principle for physical systems in which quantum-mechanical vacuum energies cannot be neglected. Specific tests include a search for the manifestation of non-metric effects in Lamb-shift transitions of hydrogenic atoms and in anomalous magnetic moments of massive leptons. We discuss how current experiments already set bounds on the violation of the equivalence principle in this sector and how new (high-precision) measurements of these quantities could provide further information to this end.
119063280
Quasilocal energy and naked black holes
We extend the Brown and York notion of quasilocal energy to include coupled electromagnetic and dilaton fields and also allow for spatial boundaries that are not orthogonal to the foliation of the spacetime. We investigate how the quasilocal quantities measured by sets of observers transform with respect to boosts. As a natural application of this work we investigate the naked black holes of Horowitz and Ross calculating the quasilocal energies measured by static versus infalling observers.
120488665
Lowest dimensional gravity
122503780
PERTURBED W3 CONFORMAL THEORIES AND SPIN-4/3 PARAFERMIONIC COSET MODELS
Renormalization group flows in W3, conformal theories are analyzed in relation to the ones in spin-4/3 parafermionic coset models and some of the operator content for new fixed points is identified.
687385
Nonclassical interferometry with intelligent light.
We study the phase sensitivity of SU(2) and SU(1,1) interferometers fed by two-mode field states which are intelligent states for Hermitian generators of the SU(2) and SU(1,1) groups, respectively. Intelligent states minimize uncertainty relations and this makes possible an essential reduction of the quantum noise in interferometers. Exact closed expressions for the minimum detectable phase shift are obtained in terms of the Jacobi polynomials. These expressions are compared with results for some conventional input states, and some known results for the squeezed input states are reviewed. It is shown that the phase sensitivity for an interferometer that employs squeezing-producing active devices (such as four-wave mixers) should be analyzed in two regimes: (i) fixed input state and variable interferometer, and (ii) fixed interferometer and variable input state. The behavior of the phase sensitivity is essentially different in these two regimes. The use of the SU(2) intelligent states allows us to achieve a phase sensitivity of order $1/\bar{N}$ (where $\bar{N}$ is the total number of photons passing through the phase shifters of the interferometer) without adding four-wave mixers. This avoids the duality in the behavior of the phase sensitivity that occurs for the squeezed input. On the other hand, the SU(1,1) intelligent states have the property of achieving the phase sensitivity of order $1/\bar{N}$ in both regimes.