8,457 research outputs found
Does Amati Relation Depend on Luminosity of GRB's Host Galaxies?
In order to test systematic of the Amati relation, the 24 long-duration GRBs
with firmly determined and are
separated into two sub-groups according to B-band luminosity of their host
galaxies. The Amati relations in the two subgroups are found to be in agreement
with each other within uncertainties. Taking into account of the well
established luminosity - metallicity relation of galaxies, no strong evolution
of the Amati relation with GRB's environment metallicity is implied in this
study.Comment: 7 pages, 3 figures and 1 table, accepted by ChJA
Classical correlation and quantum discord sharing of Dirac fields in noninertial frames
The classical and quantum correlations sharing between modes of the Dirac
fields in the noninertial frame are investigated. It is shown that: (i) The
classical correlation for the Dirac fields decreases as the acceleration
increases, which is different from the result of the scalar field that the
classical correlation is independent of the acceleration; (ii) There is no
simple dominating relation between the quantum correlation and entanglement for
the Dirac fields, which is unlike the scalar case where the quantum correlation
is always over and above the entanglement; (iii) As the acceleration increases,
the correlations between modes and and between modes and
increase, but the correlations between modes and decrease.Comment: 15 pages, 6 figures; Accepted for publication in Phys. Rev.
Explicit calculation of strong solution on linear parabolic equation
In this paper, we give the existence and uniqueness of the strong solution of
one dimensional linear parabolic equation with mixed boundary conditions. The
boundary conditions can be any kind of mixed Dirichlet, Neumann and Robin
boundary conditions. We use the extension method to get the unique solution.
Furthermore, the method can also be easily implemented as a numerical method.
Some simple examples are presented.Comment: 10 page
All-versus-nothing violation of local realism in the one-dimensional Ising model
We show all-versus-nothing proofs of Bell's theorem in the one-dimensional
transverse-field Ising model, which is one of the most important exactly
solvable models in the field of condensed matter physics. Since this model can
be simulated with nuclear magnetic resonance, our work might lead to a fresh
approach to experimental test of the Greenberger-Horne-Zeilinger contradiction
between local realism and quantum mechanics.Comment: 4 page
Numerical algorithms of the two-dimensional Feynman-Kac equation for reaction and diffusion processes
This paper provides a finite difference discretization for the backward
Feynman-Kac equation, governing the distribution of functionals of the path for
a particle undergoing both reaction and diffusion [Hou and Deng, J. Phys. A:
Math. Theor., {\bf51}, 155001 (2018)]. Numerically solving the equation with
the time tempered fractional substantial derivative and tempered fractional
Laplacian consists in discretizing these two non-local operators. Here, using
convolution quadrature, we provide a first-order and second-order schemes for
discretizing the time tempered fractional substantial derivative, which doesn't
require the assumption of the regularity of the solution in time; we use the
finite difference method to approximate the two-dimensional tempered fractional
Laplacian, and the accuracy of the scheme depends on the regularity of the
solution on rather than the whole space. Lastly, we verify the
predicted convergence orders and the effectiveness of the presented schemes by
numerical examples.Comment: 37 pages, 7 table
Tight Correlation-Function Bell Inequality for Multipartite -Dimensional System
We generalize the correlation functions of the Clauser-Horne-Shimony-Holt
(CHSH) inequality to multipartite d-dimensional systems. All the Bell
inequalities based on this generalization take the same simple form as the CHSH
inequality. For small systems, numerical results show that the new inequalities
are tight and we believe this is also valid for higher dimensional systems.
Moreover, the new inequalities are relevant to the previous ones and for
bipartite system, our inequality is equivalent to the
Collins-Gisin-Linden-Masser-Popescu (CGLMP) inequality.Comment: 4 pages; Accepted by PR
Dependence of entanglement on initial states under amplitude damping channel in non-inertial frames
Under amplitude damping channel, the dependence of the entanglement on the
initial states and , which reduce to four
orthogonal Bell states if we take the parameter of states are investigated. We find that the entanglements for different
initial states will decay along different curves even with the same
acceleration and parameter of the states. We note that, in an inertial frame,
the sudden death of the entanglement for will occur if
, while it will not take place for for any
. We also show that the possible range of the sudden death of the
entanglement for is larger than that for . There
exist two groups of Bell state here we can't distinguish only by concurrence.Comment: 5 pages, 2 figure
Revisiting Optimal Power Control: its Dual Effect on SNR and Contention
In this paper we study a transmission power tune problem with densely
deployed 802.11 Wireless Local Area Networks (WLANs). While previous papers
emphasize on tuning transmission power with either PHY or MAC layer separately,
optimally setting each Access Point's (AP's) transmission power of a densely
deployed 802.11 network considering its dual effects on both layers remains an
open problem. In this work, we design a measure by evaluating impacts of
transmission power on network performance on both PHY and MAC layers. We show
that such an optimization problem is intractable and then we investigate and
develop an analytical framework to allow simple yet efficient solutions.
Through simulations and numerical results, we observe clear benefits of the
dual-effect model compared to solutions optimizing solely on a single layer;
therefore, we conclude that tuning transmission power from a dual layer
(PHY-MAC) point of view is essential and necessary for dense WLANs. We further
form a game theoretical framework and investigate above power-tune problem in a
strategic network. We show that with decentralized and strategic users, the
Nash Equilibrium (N.E.) of the corresponding game is in-efficient and
thereafter we propose a punishment based mechanism to enforce users to adopt
the social optimal strategy profile under both perfect and imperfect sensing
environments
Numerical scheme for the Fokker-Planck equations describing anomalous diffusions with two internal states
Recently, the fractional Fokker-Planck equations (FFPEs) with multiple
internal states are built for the particles undergoing anomalous diffusion with
different waiting time distributions for different internal states, which
describe the distribution of positions of the particles [Xu and Deng, Math.
Model. Nat. Phenom., , 10 (2018)]. In this paper, we first develop
the Sobolev regularity of the FFPEs with two internal states, including the
homogeneous problem with smooth and nonsmooth initial values and the
inhomogeneous problem with vanishing initial value, and then we design the
numerical scheme for the system of fractional partial differential equations
based on the finite element method for the space derivatives and convolution
quadrature for the time fractional derivatives. The optimal error estimates of
the scheme under the above three different conditions are provided for both
space semidiscrete and fully discrete schemes. Finally, one- and
two-dimensional numerical experiments are performed to confirm our theoretical
analysis and the predicted convergence order.Comment: 30 page
Algorithm implementation and numerical analysis for the two-dimensional tempered fractional Laplacian
Tempered fractional Laplacian is the generator of the tempered isotropic
L\'evy process [W.H. Deng, B.Y. Li, W.Y. Tian, and P.W. Zhang, Multiscale
Model. Simul., 16(1), 125-149, 2018]. This paper provides the finite difference
discretization for the two dimensional tempered fractional Laplacian
. Then we use it to solve the tempered
fractional Poisson equation with Dirichlet boundary conditions and derive the
error estimates. Numerical experiments verify the convergence rates and
effectiveness of the schemes.Comment: 27 pages, 4 figure
- …