3,403 research outputs found
Berry-Esseen Bounds of Normal and Non-normal Approximation for Unbounded Exchangeable Pairs
An exchangeable pair approach is commonly taken in the normal and non-normal
approximation using Stein's method. It has been successfully used to identify
the limiting distribution and provide an error of approximation. However, when
the difference of the exchangeable pair is not bounded by a small deterministic
constant, the error bound is often not optimal. In this paper, using the
exchangeable pair approach of Stein's method, a new Berry-Esseen bound for an
arbitrary random variable is established without a bound on the difference of
the exchangeable pair. An optimal convergence rate for normal and non-normal
approximation is achieved when the result is applied to various examples
including the quadratic forms, general Curie-Weiss model, mean field Heisenberg
model and colored graph model.Comment: 51 page
Controlling decoherence speed limit of a single impurity atom in a Bose-Einstein-condensate reservoir
We study the decoherence speed limit (DSL) of a single impurity atom immersed
in a Bose-Einsteincondensed (BEC) reservoir when the impurity atom is in a
double-well potential. We demonstrate how the DSL of the impurity atom can be
manipulated by engineering the BEC reservoir and the impurity potential within
experimentally realistic limits. We show that the DSL can be controlled by
changing key parameters such as the condensate scattering length, the effective
dimension of the BEC reservoir, and the spatial configuration of the
double-well potential imposed on the impurity. We uncover the physical
mechanisms of controlling the DSL at root of the spectral density of the BEC
reservoir.Comment: 8 pages, 8 figure
Adversarial Discriminative Heterogeneous Face Recognition
The gap between sensing patterns of different face modalities remains a
challenging problem in heterogeneous face recognition (HFR). This paper
proposes an adversarial discriminative feature learning framework to close the
sensing gap via adversarial learning on both raw-pixel space and compact
feature space. This framework integrates cross-spectral face hallucination and
discriminative feature learning into an end-to-end adversarial network. In the
pixel space, we make use of generative adversarial networks to perform
cross-spectral face hallucination. An elaborate two-path model is introduced to
alleviate the lack of paired images, which gives consideration to both global
structures and local textures. In the feature space, an adversarial loss and a
high-order variance discrepancy loss are employed to measure the global and
local discrepancy between two heterogeneous distributions respectively. These
two losses enhance domain-invariant feature learning and modality independent
noise removing. Experimental results on three NIR-VIS databases show that our
proposed approach outperforms state-of-the-art HFR methods, without requiring
of complex network or large-scale training dataset
Classical Equation of Electromagnetic Field in the Higgs Boson Field and Estimation on the Static Electrical Polarizability of Leptons
In our paper we derived the classical motion equation of electromagnetic
field in space with Higgs field and by means of it discussed the distributions
of charge and current formed when the static electrical and magnetic fields are
interacting with the spherically symmetrical Higgs field, and predicted the
electrical polarizability of electron
Path Integral by Space-time Slicing Approximation In Open Bosonic String Field
In our paper, we considered how to apply the traditional Feynman path
integral to string field. By constructing the complete set in Fock space of
non-relativistic and relativistic open bosonic string fields, we extended
Feynman path integral to path integral on functional field and use it to
quantize open bosonic string field
Impurity-induced Dicke quantum phase transition in an impurity-doped cavity-Bose-Einstein condensate
We present a new generalized Dicke model, an impurity-doped Dicke model
(IDDM), by the use of an impurity-doped cavity-Bose-Einstein condensate. It is
shown that the impurity atom can induce Dicke quantum phase transition (QPT)
from the normal phase to superradiant phase at a critic value of the impurity
population. It is found that the IDDM exhibits continuous Dicke QPT with an
infinite number of critical points, which is significantly different from that
observed in the standard Dicke model with only one critical point. It is
revealed that the impurity-induced Dicke QPT can happen in an arbitrary
coupling regime of the cavity field and atoms while the Dicke QPT in the
standard Dicke model occurs only in the strong coupling regime of the cavity
field and atoms. This opens a way to observe the Dicke QPT in the intermediate
and even weak coupling regime of the cavity field and atoms.Comment: 7 pages, 3 figure
Limit theorems with rate of convergence under sublinear expectations
Under the sublinear expectation for a given set of linear expectations , we establish a new law of large numbers and a new central limit
theorem with rate of convergence. We present some interesting special cases and
discuss a related statistical inference problem. We also give an approximation
and a representation of the -normal distribution, which was used as the
limit in Peng (2007)'s central limit theorem, in a probability space.Comment: 34 page
Finite element computations on quadtree meshes: strain smoothing and semi-analytical formulation
This short communication discusses two alternate techniques to treat hanging
nodes in a quadtree mesh. Both the techniques share similarities, in that, they
require only boundary information. Moreover, they do not require an explicit
form of the shape functions, unlike the conventional approaches, for example,
as in the work of Gupta \cite{gupta1978} or Tabarraei and Sukumar
\cite{tabarraeisukumar2005}. Hence, no special numerical integration technique
is required. One of the techniques relies on the strain projection procedure,
whilst the other is based on the scaled boundary finite element method.
Numerical examples are presented to demonstrate the accuracy and the
convergence properties of the two techniques
Quantum speed-up of multiqubit open system via dynamical decoupling pulses
We present a method to accelerate the dynamical evolution of multiqubit open
system by employing dynamical decoupling pulses (DDPs) when the qubits are
initially in W-type states. It is found that this speed-up evolution can be
achieved in both of the weak-coupling regime and the strong-coupling regime.
The physical mechanism behind the acceleration evolution is explained as the
result of the joint action of the non-Markovianity of reservoirs and the
excited-state population of qubits. It is shown that both of the
non-Markovianity and the excited-state population can be controlled by DDPs to
realize the quantum speed-up.Comment: 8 pages, 5 figure
Free vibration and mechanical buckling of plates with in-plane material inhomogeneity - a three dimensional consistent approach
In this article, we study the free vibration and the mechanical buckling of
plates using a three dimensional consistent approach based on the scaled
boundary finite element method. The in-plane dimensions of the plate are
modeled by two-dimensional higher order spectral element. The solution through
the thickness is expressed analytically with Pade expansion. The stiffness
matrix is derived directly from the three dimensional solutions and by
employing the spectral element, a diagonal mass matrix is obtained. The
formulation does not require ad hoc shear correction factors and no numerical
locking arises. The material properties are assumed to be temperature
independent and graded only in the in-plane direction by a simple power law.
The effective material properties are estimated using the rule of mixtures. The
influence of the material gradient index, the boundary conditions and the
geometry of the plate on the fundamental frequencies and critical buckling load
are numerically investigated
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