1,999,798 research outputs found
A note on the paper, "Quarks or Leptons?"
In the context of a recent description of Fermions as Kerr-Newman type black
holes with Quantum Mechanical inputs, it is shown how the quark picture can be
recovered. The advantage is that in the process we obtain a rationale for such
features as the puzzling fractional charges of the quarks, their masses,
confinement and handedness in a unified scheme.Comment: 5 pages, Te
A Short Range Force
Gravitomagnetic and gravitoelectric forces have been studied for sometime and
tests for detecting such forces arising from the earth, are under way. We apply
similar considerations at the level of elementary particles in a formulation
using General Relativity, and deduce the presence of short range forces. A
possible candidate could be the somewhat recently detected but otherwise
mysterious short range force, mediated by massive "photons".Comment: 4 pages, TeX, Based on the paper in the Fifth International
Symposium, Frontiers of Fundamental Physic
Negative Energy Solutions and Symmetries
We revisit the negative energy solutions of the Dirac equation, which become
relevant at very high energies and study several symmetries which follow
therefrom. The consequences are briefly examined.Comment: 11 pages, Late
Black Hole Thermodynamics and Electromagnetism
We show a strong parallel between the Hawking, Beckenstein black hole
Thermodynamics and electromagnetism: When the gravitational coupling constant
transform into the electromagnetic coupling constant, the Schwarzchild radius,
the Beckenstein temperature, the Beckenstein decay time and the Planck mass
transform to respectively the Compton wavelength, the Hagedorn temperature, the
Compton time and a typical elementary particle mass. The reasons underlying
this parallalism are then discussed in detail.Comment: 10 pages, te
Energy and Mass Generation
Modifications in the energy momentum dispersion laws due to a noncommutative
geometry, have been considered in recent years. We examine the oscillations of
extended objects in this perspective and find that there is now a "generation"
of energy.Comment: 13 pages Late
Entanglement in a Noninteracting Mesoscopic Structure
We study the time dependent electron-electron and electron-hole correlations
in a mesoscopic device which is splitting an incident current of free fermions
into two spatially separated particle streams. We analyze the appearance of
entanglement as manifested in a Bell inequality test and discuss its origin in
terms of local spin-singlet correlations already present in the initial channel
and the action of post-selection during the Bell type measurement. The time
window over which the Bell inequality is violated is determined in the
tunneling limit and for the general situation with arbitrary transparencies. We
compare our results with alternative Bell inequality tests based on coincidence
probabilities.Comment: 9 pages, 2 figure
A bimodal dust grain distribution in the IC 434 HII region
Recent studies of dust in the interstellar medium have challenged the
capabilities and validity of current dust models, indicating that the
properties of dust evolve as it transits between different phases of the
interstellar medium. We conduct a multi-wavelength study of the dust emission
from the ionized gas of the IC 434 emission nebula, and combine this with
modeling, from large scales that provide insight into the history of the IC
434/L1630 region, to small scales that allow us to infer quantitative
properties of the dust content inside the H II region. The dust enters the H II
region through momentum transfer with a champagne flow of ionized gas, set up
by a chance encounter between the L1630 molecular cloud and the star cluster of
Ori. We observe two clearly separated dust populations inside the
ionized gas, that show different observational properties, as well as
contrasting optical properties. Population A is colder ( 25 K) than
predicted by widely-used dust models, its temperature is insensitive to an
increase of the impinging radiation field, is momentum-coupled to the gas, and
efficiently absorbs radiation pressure to form a dust wave at 1.0 pc ahead of
Ori AB. Population B is characterized by a constant [20/30] flux ratio
throughout the HII region, heats up to 75 K close to the star, and is
less efficient in absorbing radiation pressure, forming a dust wave at 0.1 pc
from the star. We conclude that the dust inside IC 434 is bimodal. The
characteristics of population A are remarkable and can not be explained by
current dust models. Population B are grains that match the classical
description of spherical, compact dust. Our results confirm recent work that
stress the importance of variations in the dust properties between different
regions of the interstellar medium.Comment: 18 pages, 10 figures, proposed for acceptance in A&
Transverse Spectra of Radiation Processes in Medium
We develop a formalism for evaluation of the transverse momentum dependence
of cross sections of the radiation processes in medium. The analysis is based
on the light-cone path integral approach to the induced radiation. The results
are applicable in both QED and QCD
Superconductor-metal transition in an ultrasmall Josephson junction biased by a noisy voltage source
Shot noise in a voltage source changes the character of the quantum
(dissipative) phase transition in an ultrasmall Josephson junction: The
superconductor-insulator transition transforms into the superconductor-metal
transition. In the metallic phase the IV curve probes the voltage distribution
generated by shot noise, whereas in the superconducting phase it probes the
counting statistics of electrons traversing the noise junction.Comment: 4 pages, 3 figures. Corrected typos and style, added reference
Casimir force for cosmological domain walls
We calculate the vacuum fluctuations that may affect the evolution of
cosmological domain walls. Considering domain walls, which are classically
stable and have interaction with a scalar field, we show that explicit symmetry
violation in the interaction may cause quantum bias that can solve the
cosmological domain wall problem.Comment: 15 pages, 2figure
- …