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Number
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Articles Title
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Abstract
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1
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Editorial
Ammar Sakaji
Full text: Acrobat
PDF (40 KB)
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2
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The Tolman-Regge Antitelephone Paradox: Its
Solution by Tachyon Mechanics
E. RECAMI
Full text: Acrobat
PDF (112 KB)
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The
possibility of solving (at least \in microphysics") all the ordinary
causal paradoxes devised for tachyons is not yet widely recognized; on the
contrary, the effectiveness of the Stuckelberg-Feynman switching principle
is often misunderstood. We want, therefore, to show in detail and
rigorously how to solve the oldest causal paradox, originally proposed by
Tolman, which is the kernel of so many further tachyon paradoxes. The key
to the solution is a careful application of tachyon kinematics, which can
be unambiguously derived from special relativity. A systematic, thorough
analysis of all tachyon paradoxes is going to appear elsewhere..
EJTP
is reproducing E. Recami's original paper: Lett. Nuovo Cimento, 44,
587 (1985).
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3
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New Physical Principle for Monte-Carlo simulations
Michail Zak
Full text: Acrobat
PDF (104 KB)
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New
physical principle for Monte-Carlo simulations has been introduced. It is
based upon coupling of dynamical equations and the corresponding Liouville
equation. The proposed approach does not require a random number generator
since randomness is generated by instability of dynamics triggered and
controlled by the feedback from the Liouville equation. Direct simulation
of evolutionary partial differential equations have been proposed,
discussed, and illustrated.
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4
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First Passage Random Walk of Coupled
Detector-System Pairs and Quantum Measurement
Fariel Shafee
Full text: Acrobat
PDF (140 KB)
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We
propose a new model for a measurement of a characteristic of a microscopic
quantum state by a large system that selects stochastically the different
eigenstates with appropriate quantum weights. Unlike previous works which
formulate a modified Schrödinger equation or an explicit modified
Hamiltonian, or more complicated mechanisms for reduction and decoherence
to introduce transition to classical stochasticity, we propose the novel
use of couplings to the environment, and random walks in the product
Hilbert space of the combined system, with first passage stopping rules,
which seem intuitively simple, as quantum weights and related stochasticity
is a commonality that must be preserved under the widest range of
applications, independent of the measured quantity and the specific
properties of the measuring device.
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5
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Underdeterminacy and Redundance in Maxwell's
Equations. I. The Origin of Gauge Freedom
Peter Enders
Full text: Acrobat
PDF (132 KB)
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The gauge freedom in the
electromagnetic potentials indicates an underdeterminacy in Maxwell's
theory. This underdeterminacy will be found in Maxwell's (1864) original
set of equations by means of Helmholtz's (1858) decomposition theorem.
Since it concerns only the longitudinal electric field, it is intimately
related to charge conservation, on the one hand, and to the transversality
of free electromagnetic waves, on the other hand (as will be discussed in
Pt. II). Exploiting the concept of Newtonian and Laplacian vector fields,
the role of the static longitudinal component of the vector potential being
not determined by Maxwell's equations, but important in quantum mechanics
(Aharonov-Bohm effect) is elucidated. These results will be exploited in
Pt.III for formulating a manifest gauge invariant canonical formulation of
Maxwell's theory as input for developing Dirac's (1949) approach to
special-relativistic dynamics.
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6
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The Origin of Mass, Spin and Interaction
B.G. Sidharth
Full text: Acrobat
PDF (103 KB)
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We
argue that a non commutative geometry at the Compton scale is at the root of mass,
Quantum Mechanical spin and QCD and electromagnetic interactions. It also
leads to a reconciliation of linearized General Relativity and Quantum
Theory.
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7
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Nonholonomic Ricci Flows and Parametric
Deformations of the Solitonic pp{Waves and Schwarzschild Solutions
Sergiu I. Vacaru
Full text: Acrobat
PDF (231 KB)
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We
study Ricci flows of some classes of physically valuable solutions in
Einstein and string gravity. The anholonomic frame method is applied for
generic off-diagonal metric ansatz when the field/ evolution equations are
transformed into exactly integrable systems of partial differential
equations. The integral varieties of such solutions, in four and five
dimensional gravity, depend on arbitrary generation and integration
functions of one, two and/ or three variables. Certain classes of
nonholonomic frame constraints allow us to select vacuum and/or Einstein
metrics, to generalize such solutions for nontrivial string (for instance,
with antisymmetric torsion fields) and matter field sources. A very
important property of this approach (originating from Finsler and Lagrange
geometry but re-defined for semi-Riemannian spaces) is that new classes of
exact solutions can be generated by nonholonomic deformations depending on
parameters associated to some generalized Geroch transforms and Ricci flow
evolution. In this paper, we apply the method to construct in explicit form
some classes of exact solutions for multi{parameter Einstein spaces and
their nonholonomic Ricci flows describing evolutions/interactions of
solitonic pp{waves and deformations of the Schwarzschild metric. We explore
possible physical consequences and speculate on their importance in modern
gravity.
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8
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Relativistic Effects on Quantum Bell States of
Massive Spin 1/2 Particles
J. P. Singh
Full text: Acrobat
PDF (195 KB)
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We
examine the behaviour of the maximally entangled Bell state of two spin 1/2 massive
particles under relativistic transformations. On the basis of explicit
calculations of the Wigner rotation and the use of transformation
properties of Dirac spinors, we establish that the constituent particles of
the Bell state undergo momentum dependent rotation of the spin orientations
characterized by the Wigner angle \phi _{W} =\tan ^{-1} \frac{\sinh \varpi
\sinh \tau }{\cosh \varpi +\cosh \tau }. However, since local unitarity is
retained in the process, the corresponding entanglement fidelity is not
lost.
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9
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Partial Swapping, Unitarity
and No-signalling
I. Chakrabarty, and B. S. Choudhury
Full text: Acrobat
PDF (83 KB)
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It
is a well known fact that a quantum state |\psi(\theta,\phi)\rangle is
represented by a point on the Bloch sphere, characterized by two parameters
\theta and \phi. In a recent work we
already proved that it is impossible to partially swap these quantum
parameters. Here in this work we will show that this impossibility theorem
is consistent with principles like unitarity of quantum mechanics and no
signalling principle.
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10
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Time scale synchronization
between two different time-delayed systems
Dibakar Ghosh
Full text: Acrobat
PDF (381 KB)
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In
this paper we consider time scale synchronization between two different
time-delay systems. Due to existence of intrinsic multiple characteristic
time scales in the chaotic time series, the usual definition for the
calculation of phase failed. To define the phase, we have used empirical
mode decomposition and the results are compared with those from continuous
wavelet transform. We investigate the generalized synchronization between
these two different chaotic time delay systems and find the existence
condition for the generalized synchronization. It has been observed that
the generalized synchronization is a weaker than the phase synchronization.
Due to the presence of scaling factor in the wavelet transform it has more
flexibility for application.
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11
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Thermodynamic Fluctuation
Theory and Gravitational Clustering of Galaxies
Mohd Shafi Khan, Naseer Iqbal and
Farooq Ahmad
Full text: Acrobat
PDF (100 KB)
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We study the phase
transitions occurring in the gravitational clustering of galaxies on the
basis of thermodynamic fluctuation theory. This is because the fluctuations
in number and energy of the particles are constantly probing the
possibility of a phase transition. A calculation of various moments of the
fluctuating thermodynamic extensive parameters like the number and energy
fluctuations, has been performed. The correlated fluctuations \left<
\bigtriangleup N \bigtriangleup U \right>, have shown some interesting
results. For weak correlations, their ensemble average is positive,
indicating that a region of density enhancement typically coincides with a
region of positive total energy. Its perturbed kinetic energy exceeds its
perturbed potential energy. Similarly an underdense region has negative
total energy since it has preferentially lost the kinetic energy of the
particles that have fled. For larger correlations the overdense regions
typically have negative total energy, underdense regions have positive
total energy. The critical value at which this switch occurs is the
critical temperature T= T_C, whose value has been calculated analytically.
At this critical value T_C, a positive \left<\bigtriangleup N\right>
is just as likely to be associated with a positive or a negative
\bigtriangleup U.
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12
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Neutrino Oscillation
Probability from Tri-Bimaximality due to Planck Scale Effects
Bipin Singh Koranga
Full text: Acrobat
PDF (102 KB)
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Current neutrino
experimental data on neutrino mixing are well describes by Tri-bi-maximal
mixing, which is predicts sin^{2}\theta_{12}=1/3,; zero U_{e3} and
\theta_{23}=45^{o}. We consider the Planck scale operator on neutrino
mixing. We assume that the neutrino masses and mixing arise through physics
at a scale intermediate between Planck scale and the electroweak braking
scale. We also assume, that just above the electroweak breaking scale
neutrino mass are nearly degenerate and the mixing is tri-bi-maximal.
Quantum gravity (Planck scale) effects lead to an effective SU(2)_{L}\times
U(1) invariant dimension-5 Lagrangian symmetry involving Standard Model. On
electroweak symmetry breaking, this operator gives rise to correction to
the neutrino masses and mixings these additional terms can be considered as
perturbation to the tri-bimaximal neutrino mass matrix. We compute the
deviation of the three mixing angles and oscillation probability. We find
that the only large change in solar mixing angle and change in maximum P_{\mu e} is about 10%.
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13
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Representation of su(1,1)
Algebra and Hall Effect
J. Sadeghi and B. Pourhassan
Full text: Acrobat
PDF (88 KB)
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In this paper we consider
the Schwinger and Heisenberg representation of su(1,1) algebra under Hall
effect. In presence of magnetic field, we obtain the generators of su(1,1)
algebra in terms of ladder operators, and magnetic field for the one and
two bosons system. Also the Casimir operator for both systems are obtained
by ladder operators.
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14
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Some LRS Bianchi Type VI0
Cosmological Models with Special Free Gravitational Fields
Raj Bali,
Ratna Banerjee, and S.K.Banerjee
Full text: Acrobat
PDF (104 KB)
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The properties of the free
gravitational fields and their invariant characterizations are discussed
and also obtained LRS Bianchi type VI0 cosmological models imposing
different conditions over the free gravitational fields. Models thus formed
are then discussed in detail with respect to their physical and kinematical
parameters in the last section of the paper.
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15
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The Motion of A Test Particle in the Gravitational
Field of A Collapsing Shell
A. Eid, and A. M. Hamzay
Full text: Acrobat
PDF (115 KB)
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We use the Israel
formalism to describe the motion of a test particle in the gravitational
field of a collapsing shell. The formalism is developed in both of
Schwarzchild and Kruskal coordinates.
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