2,051 research outputs found
Pilot Wave model that includes creation and annihilation of particles
The purpose of this paper is to come up with a Pilot Wave model of quantum
field theory that incorporates particle creation and annihilation without
sacrificing determinism. This has been previously attempted in an article by
the same author titled "Incorporating particle creation and annihilation in
Pilot Wave model", in a much less satisfactory way. In this paper I would like
to "clean up" some of the things. In particular, I would like to get rid of a
very unnatural concept of "visibility" of particles, which makes the model much
simpler. On the other hand, I would like to add a mechanism for decoherence,
which was absent in the previous version.Comment: 9 pages, no figure
A Multi Megawatt Cyclotron Complex to Search for CP Violation in the Neutrino Sector
A Multi Megawatt Cyclotron complex able to accelerate H2+ to 800 MeV/amu is
under study. It consists of an injector cyclotron able to accelerate the
injected beam up to 50 MeV/n and of a booster ring made of 8 magnetic sectors
and 8 RF cavities. The magnetic field and the forces on the superconducting
coils are evaluated using the 3-D code OPERA. The injection and extraction
trajectories are evaluated using the well tested codes developed by the MSU
group in the '80s. The advantages to accelerate H2+ are described and
preliminary evaluations on the feasibility and expected problems to build the
injector cyclotron and the ring booster are here presented.Comment: Presentation at Cyclotron'10 conference, Lanzhou, China, Sept 7, 201
Wave Packets Propagation in Quantum Gravity
Wave packet broadening in usual quantum mechanics is a consequence of
dispersion behavior of the medium which the wave propagates in it. In this
paper, we consider the problem of wave packet broadening in the framework of
Generalized Uncertainty Principle(GUP) of quantum gravity. New dispersion
relations are derived in the context of GUP and it has been shown that there
exists a gravitational induced dispersion which leads to more broadening of the
wave packets. As a result of these dispersion relations, a generalized
Klein-Gordon equation is obtained and its interpretation is given.Comment: 9 pages, no figur
Pure States, Mixed States and Hawking Problem in Generalized Quantum Mechanics
This paper is the continuation of a study into the information paradox
problem started by the author in his earlier works. As previously, the key
instrument is a deformed density matrix in quantum mechanics of the early
universe. It is assumed that the latter represents quantum mechanics with
fundamental length. It is demonstrated that the obtained results agree well
with the canonical viewpoint that in the processes involving black holes pure
states go to the mixed ones in the assumption that all measurements are
performed by the observer in a well-known quantum mechanics. Also it is shown
that high entropy for Planck remnants of black holes appearing in the
assumption of the Generalized Uncertainty Relations may be explained within the
scope of the density matrix entropy introduced by the author previously. It is
noted that the suggested paradigm is consistent with the Holographic Principle.
Because of this, a conjecture is made about the possibility for obtaining the
Generalized Uncertainty Relations from the covariant entropy bound at high
energies in the same way as R. Bousso has derived Heisenberg uncertainty
principle for the flat space.Comment: 12 pages,no figures,some corrections,new reference
Gravitational Wave Bursts from Cosmic Superstrings with Y-junctions
Cosmic superstring loops generically contain strings of different tensions
that meet at Y-junctions. These loops evolve non-periodically in time, and have
cusps and kinks that interact with the junctions. We study the effect of
junctions on the gravitational wave signal emanating from cosmic string cusps
and kinks. We find that earlier results on the strength of individual bursts
from cusps and kinks on strings without junctions remain largely unchanged, but
junctions give rise to additional contributions to the gravitational wave
signal coming from strings expanding at the speed of light at a junction and
kinks passing through a junction.Comment: 20 pages, 5 figure
Maxwell-Chern-Simons Theory With Boundary
The Maxwell-Chern-Simons (MCS) theory with planar boundary is considered. The
boundary is introduced according to Symanzik's basic principles of locality and
separability. A method of investigation is proposed, which, avoiding the
straight computation of correlators, is appealing for situations where the
computation of propagators, modified by the boundary, becomes quite complex.
For MCS theory, the outcome is that a unique solution exists, in the form of
chiral conserved currents, satisfying a Kac-Moody algebra, whose central charge
does not depend on the Maxwell term.Comment: 30 page
N=2 SYM Action as a BRST Exact Term, Topological Yang Mills and Instantons
By constructing a nilpotent extended BRST operator \bs that involves the
N=2 global supersymmetry transformations of one chirality, we show that the
standard N=2 off-shell Super Yang Mills Action can be represented as an exact
BRST term \bs \Psi, if the gauge fermion is allowed to depend on the
inverse powers of supersymmetry ghosts. By using this nonanalytical structure
of the gauge fermion (via inverse powers of supersymmetry ghosts), we give
field redefinitions in terms of composite fields of supersymmetry ghosts and
N=2 fields and we show that Witten's topological Yang Mills theory can be
obtained from the ordinary Euclidean N=2 Super Yang Mills theory directly by
using such field redefinitions. In other words, TYM theory is obtained as a
change of variables (without twisting). As a consequence it is found that
physical and topological interpretations of N=2 SYM are intertwined together
due to the requirement of analyticity of global SUSY ghosts. Moreover, when
after an instanton inspired truncation of the model is used, we show that the
given field redefinitions yield the Baulieu-Singer formulation of Topological
Yang Mills.Comment: Latex, 1+15 pages. Published versio
Spectroscopy of the quantum black hole
We develop the idea that, in quantum gravity where the horizon fluctuates, a
black hole should have a discrete mass spectrum with concomitant line emission.
Simple arguments fix the spacing of the lines, which should be broad but
unblended. Assuming uniformity of the matrix elements for quantum transitions
between near levels, we work out the probabilities for the emission of a
specified series of quanta and the intensities of the spectral lines. The
thermal character of the radiation is entirely due to the degeneracy of the
levels, the same degeneracy that becomes manifest as black hole entropy. One
prediction is that there should be no lines with wavelength of order the black
hole size or larger. This makes it possible to test quantum gravity with black
holes well above Planck scale.Comment: RevTeX, 9 page
Quasi-normal modes of charged, dilaton black holes
In this paper we study the perturbations of the charged, dilaton black hole,
described by the solution of the low energy limit of the superstring action
found by Garfinkle, Horowitz and Strominger. We compute the complex frequencies
of the quasi-normal modes of this black hole, and compare the results with
those obtained for a Reissner-Nordstr\"{o}m and a Schwarzschild black hole. The
most remarkable feature which emerges from this study is that the presence of
the dilaton breaks the \emph{isospectrality} of axial and polar perturbations,
which characterizes both Schwarzschild and Reissner-Nordstr\"{o}m black holes.Comment: 15 pages, 5 figure
An Improved Calculation of the Non-Gaussian Halo Mass Function
The abundance of collapsed objects in the universe, or halo mass function, is
an important theoretical tool in studying the effects of primordially generated
non-Gaussianities on the large scale structure. The non-Gaussian mass function
has been calculated by several authors in different ways, typically by
exploiting the smallness of certain parameters which naturally appear in the
calculation, to set up a perturbative expansion. We improve upon the existing
results for the mass function by combining path integral methods and saddle
point techniques (which have been separately applied in previous approaches).
Additionally, we carefully account for the various scale dependent combinations
of small parameters which appear. Some of these combinations in fact become of
order unity for large mass scales and at high redshifts, and must therefore be
treated non-perturbatively. Our approach allows us to do this, and to also
account for multi-scale density correlations which appear in the calculation.
We thus derive an accurate expression for the mass function which is based on
approximations that are valid over a larger range of mass scales and redshifts
than those of other authors. By tracking the terms ignored in the analysis, we
estimate theoretical errors for our result and also for the results of others.
We also discuss the complications introduced by the choice of smoothing filter
function, which we take to be a top-hat in real space, and which leads to the
dominant errors in our expression. Finally, we present a detailed comparison
between the various expressions for the mass functions, exploring the accuracy
and range of validity of each.Comment: 28 pages, 13 figures; v2: text reorganized and some figured modified
for clarity, results unchanged, references added. Matches version published
in JCA
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