1,189,297 research outputs found
Mechanism of Gravity Impulse
It is well-known that energy-momentum is the source of gravitational field.
For a long time, it is generally believed that only stars with huge masses can
generate strong gravitational field. Based on the unified theory of
gravitational interactions and electromagnetic interactions, a new mechanism of
the generation of gravitational field is studied. According to this mechanism,
in some special conditions, electromagnetic energy can be directly converted
into gravitational energy, and strong gravitational field can be generated
without massive stars. Gravity impulse found in experiments is generated by
this mechanism.Comment: 10 page
Spin-Spin Interactions in Gauge Theory of Gravity, Violation of Weak Equivalence Principle and New Classical Test of General Relativity
For a long time, it is generally believed that spin-spin interactions can
only exist in a theory where Lorentz symmetry is gauged, and a theory with
spin-spin interactions is not perturbatively renormalizable. But this is not
true. By studying the motion of a spinning particle in gravitational field, it
is found that there exist spin-spin interactions in gauge theory of gravity.
Its mechanism is that a spinning particle will generate gravitomagnetic field
in space-time, and this gravitomagnetic field will interact with the spin of
another particle, which will cause spin-spin interactions. So, spin-spin
interactions are transmitted by gravitational field. The form of spin-spin
interactions in post Newtonian approximations is deduced. This result can also
be deduced from the Papapetrou equation. This kind of interactions will not
affect the renormalizability of the theory. The spin-spin interactions will
violate the weak equivalence principle, and the violation effects are
detectable. An experiment is proposed to detect the effects of the violation of
the weak equivalence principle.Comment: 17 pages, no figur
The Cosmological Constant is Probably Zero, and a Proof is Possibly Right
Hawking proposed that the cosmological constant is probably zero in quantum
cosmology. Duff claimed that Hawking's proof is invalidated. Using the right
configuration for the wave function of the universe, we provide a complete
proof.Comment: 6 pages, modified versio
Ballistic transport: A view from the quantum theory of motion
Ballistic transport of electrons through a quantum wire with a constriction
is studied in terms of Bohm's interpretation of quantum mechanics, in which the
concept of a particle orbit is permitted. The classical bouncing ball
trajectories, which justify the name ``ballistic transport'', are established
in the large wave number limit. The formation and the vital role of quantum
vortices is investigated.Comment: 14 pages, revtex, 4 postscript figure
Non-Relativistic Limit of Dirac Equations in Gravitational Field and Quantum Effects of Gravity
Based on unified theory of electromagnetic interactions and gravitational
interactions, the non-relativistic limit of the equation of motion of a charged
Dirac particle in gravitational field is studied. From the Schrodinger equation
obtained from this non-relativistic limit, we could see that the classical
Newtonian gravitational potential appears as a part of the potential in the
Schrodinger equation, which can explain the gravitational phase effects found
in COW experiments. And because of this Newtonian gravitational potential, a
quantum particle in earth's gravitational field may form a gravitationally
bound quantized state, which had already been detected in experiments. Three
different kinds of phase effects related to gravitational interactions are
discussed in this paper, and these phase effects should be observable in some
astrophysical processes. Besides, there exists direct coupling between
gravitomagnetic field and quantum spin, radiation caused by this coupling can
be used to directly determine the gravitomagnetic field on the surface of a
star.Comment: 12 pages, no figur
Perturbation of coupling matrices and its effect on the synchronizability in arrays of coupled chaotic systems
In a recent paper, wavelet analysis was used to perturb the coupling matrix
in an array of identical chaotic systems in order to improve its
synchronization. As the synchronization criterion is determined by the second
smallest eigenvalue of the coupling matrix, the problem is
equivalent to studying how of the coupling matrix changes with
perturbation. In the aforementioned paper, a small percentage of the wavelet
coefficients are modified. However, this result in a perturbed matrix where
every element is modified and nonzero. The purpose of this paper is to present
some results on the change of due to perturbation. In particular,
we show that as the number of systems , perturbations which only
add local coupling will not change . On the other hand, we show that
there exists perturbations which affect an arbitrarily small percentage of
matrix elements, each of which is changed by an arbitrarily small amount and
yet can make arbitrarily large. These results give conditions on
what the perturbation should be in order to improve the synchronizability in an
array of coupled chaotic systems. This analysis allows us to prove and explain
some of the synchronization phenomena observed in a recently studied network
where random coupling are added to a locally connected array. Finally we
classify various classes of coupling matrices such as small world networks and
scale free networks according to their synchronizability in the limit.Comment: 7 pages, 2 figures, 1 tabl
Horava-Lifshitz Gravity and Effective Theory of the Fractional Quantum Hall Effect
We show that Horava-Lifshitz gravity theory can be employed as a covariant
framework to build an effective field theory for the fractional quantum Hall
effect that respects all the spacetime symmetries such as non-relativistic
diffeomorphism invariance and anisotropic Weyl invariance as well as the gauge
symmetry. The key to this formalism is a set of correspondence relations that
maps all the field degrees of freedom in the Horava-Lifshitz gravity theory to
external background (source) fields among others in the effective action of the
quantum Hall effect, according to their symmetry transformation properties. We
originally derive the map as a holographic dictionary, but its form is
independent of the existence of holographic duality. This paves the way for the
application of Horava-Lifshitz holography on fractional quantum Hall effect.
Using the simplest holographic Chern-Simons model, we compute the low energy
effective action at leading orders and show that it captures universal
electromagnetic and geometric properties of quantum Hall states, including the
Wen-Zee shift, Hall viscosity, angular momentum density and their relations. We
identify the shift function in Horava-Lifshitz gravity theory as minus of
guiding center velocity and conjugate to guiding center momentum. This enables
us to distinguish guiding center angular momentum density from the internal
one, which is the sum of Landau orbit spin and intrinsic (topological) spin of
the composite particles. Our effective action shows that Hall viscosity is
minus half of the internal angular momentum density and proportional to Wen-Zee
shift, and Hall bulk viscosity is half of the guiding center angular momentum
density.Comment: 69 page
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