16,269 research outputs found
Freezing and melting equations for the -6 Lennard-Jones systems
We generalize previous approach of Khrapak and Morfill [J. Chem. Phys. {\bf
134}, 094108 (2011)] to construct simple and sufficiently accurate freezing and
melting equations for the conventional Lennard-Jones (LJ) system to -6 LJ
systems, using the accurate results for the triple points of these systems
published by Sousa {\it et al.} [J. Chem. Phys. {\bf 136}, 174502 (2012)].Comment: 2 pages, one figur
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
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
Dynamics of entanglement in the transverse Ising model
We study the evolution of nearest-neighbor entanglement in the one
dimensional Ising model with an external transverse field. The system is
initialized as the so called "thermal ground state" of the pure Ising model. We
analyze properties of generation of entanglement for different regions of
external transverse fields. We find that the derivation of the time at which
the entanglement reaches its first maximum with respect to the reciprocal
transverse field has a minimum at the critical point. This is a new indicator
of quantum phase transition.Comment: To be published in PR
Power-Law Distributions in Circulating Money: Effect of Preferential Behavior
We introduce preferential behavior into the study on statistical mechanics of
money circulation. The computer simulation results show that the preferential
behavior can lead to power laws on distributions over both holding time and
amount of money held by agents. However, some constraints are needed in
generation mechanism to ensure the robustness of power-law distributions.Comment: 4 pages, 2 figure
Extended Variational Cluster Approximation
The variational cluster approximation (VCA) proposed by M. Potthoff {\it et
al.} [Phys. Rev. Lett. {\bf 91}, 206402 (2003)] is extended to electron or spin
systems with nonlocal interactions. By introducing more than one source field
in the action and employing the Legendre transformation, we derive a
generalized self-energy functional with stationary properties. Applying this
functional to a proper reference system, we construct the extended VCA (EVCA).
In the limit of continuous degrees of freedom for the reference system, EVCA
can recover the cluster extension of the extended dynamical mean-field theory
(EDMFT). For a system with correlated hopping, the EVCA recovers the cluster
extension of the dynamical mean-field theory for correlated hopping. Using a
discrete reference system composed of decoupled three-site single impurities,
we test the theory for the extended Hubbard model. Quantitatively good results
as compared with EDMFT are obtained. We also propose VCA (EVCA) based on
clusters with periodic boundary conditions. It has the (extended) dynamical
cluster approximation as the continuous limit. A number of related issues are
discussed.Comment: 23 pages, 5 figures, statements about DCA corrected; published
versio
Extremal Isolated Horizon/CFT Correspondence
The near-horizon limit of the extremal (weakly) isolated horizon is obtained
under the Bondi-like coordinates. For the vacuum case, explicit coordinate
transformation relating the near-horizon metric under the Bondi-like
coordinates and the standard Poincar\'e-type or global near-horizon metric of
the extremal Kerr black hole is found, which shows that the two geometries are
the same. Combined with the known thermodynamics of the (weakly) isolated
horizon, it is argued that the Kerr/CFT correspondence can be generalized to
the case of a large class of non-stationary extremal black holes.Comment: 13 pages, no figure, revtex4; v2: abstract revised, minor
corrections, references added; v3: minor corrections, version to appear in
PR
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