7,957 research outputs found
Generalized Gaussian Process Regression Model for Non-Gaussian Functional Data
In this paper we propose a generalized Gaussian process concurrent regression
model for functional data where the functional response variable has a
binomial, Poisson or other non-Gaussian distribution from an exponential family
while the covariates are mixed functional and scalar variables. The proposed
model offers a nonparametric generalized concurrent regression method for
functional data with multi-dimensional covariates, and provides a natural
framework on modeling common mean structure and covariance structure
simultaneously for repeatedly observed functional data. The mean structure
provides an overall information about the observations, while the covariance
structure can be used to catch up the characteristic of each individual batch.
The prior specification of covariance kernel enables us to accommodate a wide
class of nonlinear models. The definition of the model, the inference and the
implementation as well as its asymptotic properties are discussed. Several
numerical examples with different non-Gaussian response variables are
presented. Some technical details and more numerical examples as well as an
extension of the model are provided as supplementary materials
Limits on the Dark Matter from AMS-02 antiproton and positron fraction data
We derive limits on the dark matter annihilation cross section and lifetime
using measurements of the AMS-02 antiproton ratio and positron fraction data.
In deriving the limits, we consider the scenario of secondary particles
accelerated in supernova remnants (SNRs) which has been argued to be able to
reasonably account for the AMS-02 high energy positron/antiproton fraction
data. We parameterize the contribution of secondary particles accelerated in
SNRs and then fit the observational data within the conventional cosmic ray
propagation model by adopting the GALPROP code. We use the likelihood ratio
test to determine the 95 confidence level upper limits of the possible dark
matter (DM) contribution to the antiproton/positron fractions measured by
AMS-02. Our limits are stronger than that set by the Fermi-LAT gamma-ray Pass 8
data of the dwarf spheroidal satellite galaxies. We also show that the solar
modulation (cosmic ray propagation) parameters can play a non-negligible role
in modifying the constraints on the dark matter annihilation cross section and
lifetime for GeV), where is the rest
mass of the dark matter particles. Using this results, we also put limits on
the effective field theory of dark matter
Exhaustion of isoperimetric regions in asymptotically hyperbolic manifolds with scalar curvature
In this paper, aimed at exploring the fundamental properties of isoperimetric
region in -manifold which is asymptotic to Anti-de
Sitter-Schwarzschild manifold with scalar curvature , we prove that
connected isoperimetric region with cannot slide off to the infinity of provided that
is not isometric to the hyperbolic space. Furthermore, we prove that
isoperimetric region with topological sphere as
boundary is exhausting regions of if Hawking mass has
uniform bound. In the case of exhausting isoperimetric region, we obtain a
formula on expansion of isoperimetric profile in terms of renormalized volume.Comment: To appear in CA
A Pyramid Scheme Model Based on "Consumption Rebate" Frauds
There are various types of pyramid schemes which have inflicted or are
inflicting losses on many people in the world. We propose a pyramid scheme
model which has the principal characters of many pyramid schemes appeared in
recent years: promising high returns, rewarding the participants recruiting the
next generation of participants, and the organizer will take all the money away
when he finds the money from the new participants is not enough to pay the
previous participants interest and rewards. We assume the pyramid scheme
carries on in the tree network, ER random network, SW small-world network or BA
scale-free network respectively, then give the analytical results of how many
generations the pyramid scheme can last in these cases. We also use our model
to analyse a pyramid scheme in the real world and we find the connections
between participants in the pyramid scheme may constitute a SW small-world
network.Comment: 17 pages, 10 figure
Exact results of two-component Fermi gas in a hard wall trap
We investigate the ground state properties of a one-dimensional two-component
ultra-cold Fermi gas in an infinite potential well. Exact Bethe ansatz solution
is used to calculate the many-body wave function of the system. Then we
evaluate the single-particle reduced density matrix and two-particle density
density correlations of the system for different interaction strengths. We find
that the momentum density distributions of the strongly interacting
two-component Fermi gas is distinct from that of free spinless Fermi gas
although their position density distributions are similar. This interacting
system may be experimentally accessible using ultra-cold atoms.Comment: 6 pages, 6 page
interaction and the structure of and in chiral effective field theory
We study the and interactions to probe the inner structure of
and with the chiral effective field theory
to the next-to-leading order. We consider the contact term, one-pion-exchange
and two-pion-exchange contributions to characterize the short-, long- and
mid-range interactions of the systems. The low energy constants
of the systems are related to those of the interaction
with quark level Lagrangian that inspired by the resonance saturation model.
The degree of freedom is also included in the loop diagrams. The
attractive potential in the channel is too weak to form
bound state, which indicates the explanation of as the compact
charmed baryon is more reasonable. Meanwhile, the potentials of the isoscalar
channels are deep enough to yield the molecular states. We obtain the masses of
the , and systems to be MeV, MeV and MeV,
respectively. The is probably the isoscalar
molecule considering its low mass puzzle. Besides, the signal
might contain the spin- and spin- two structures,
which can qualitatively explain the significant decay ratio to and
. We also study the systems and predict the
possible molecular states in the isoscalar channels. We hope experimentalists
could hunt for the open charmed molecular pentaquarks in the
final state.Comment: 11 pages, 4 figures and 4 table
Clique Gossiping
This paper proposes and investigates a framework for clique gossip protocols.
As complete subnetworks, the existence of cliques is ubiquitous in various
social, computer, and engineering networks. By clique gossiping, nodes interact
with each other along a sequence of cliques. Clique-gossip protocols are
defined as arbitrary linear node interactions where node states are vectors
evolving as linear dynamical systems. Such protocols become clique-gossip
averaging algorithms when node states are scalars under averaging rules. We
generalize the classical notion of line graph to capture the essential node
interaction structure induced by both the underlying network and the specific
clique sequence. We prove a fundamental eigenvalue invariance principle for
periodic clique-gossip protocols, which implies that any permutation of the
clique sequence leads to the same spectrum for the overall state transition
when the generalized line graph contains no cycle. We also prove that for a
network with nodes, cliques with smaller sizes determined by factors of
can always be constructed leading to finite-time convergent clique-gossip
averaging algorithms, provided is not a prime number. Particularly, such
finite-time convergence can be achieved with cliques of equal size if and
only if is divisible by and they have exactly the same prime factors. A
proven fastest finite-time convergent clique-gossip algorithm is constructed
for clique-gossiping using size- cliques. Additionally, the acceleration
effects of clique-gossiping are illustrated via numerical examples
Constraining the anomalous Higgs boson coupling in + production
Higgs boson production in association with a photon (+) offers a
promising channel to test the Higgs boson to photon coupling at various energy
scales. Its potential sensitivity to anomalous couplings of the Higgs boson has
not been explored with the proton-proton collision data. In this paper, we
reinterpret the latest ATLAS + resonance search results within the
Standard Model effective field theory (EFT) framework, using 36.1 fb of
proton-proton collision data recorded with the ATLAS detector at
TeV. Constraints on the Wilson coefficients of dimension-six EFT operators
related to the Higgs boson to photon coupling are provided for the first time
in the + final state at the LHC.Comment: 10 pages, 3 figure
Hierarchicality of Trade Flow Networks Reveals Complexity of Products
With globalization, countries are more connected than before by trading
flows, which currently amount to at least 36 trillion dollars. Interestingly,
approximately 30-60 percent of global exports consist of intermediate products.
Therefore, the trade flow network of a particular product with high added
values can be regarded as a value chain. The problem is weather we can
discriminate between these products based on their unique flow network
structure. This paper applies the flow analysis method developed in ecology to
638 trading flow networks of different products. We claim that the allometric
scaling exponent can be used to characterize the degree of
hierarchicality of a flow network, i.e., whether the trading products flow on
long hierarchical chains. Then, the flow networks of products with higher added
values and complexity, such as machinery&transport equipment with larger
exponents, are highlighted. These higher values indicate that their trade flow
networks are more hierarchical. As a result, without extra data such as global
input-output table, we can identify the product categories with higher
complexity and the relative importance of a country in the global value chain
solely by the trading network.Comment: 14 pages,7 figure
Flow Decomposition Reveals Dynamical Structure of Markov Process
Markov process is widely applied in almost all aspects of literature,
especially important for understanding non-equilibrium processes. We introduce
a decomposition to general Markov process in this paper. This decomposition
decomposes the process into 3 independent parts: stationary distribution,
symmetric detailed-balance part and anti-symmetric breaking detailed-balance
part. This complete decomposition captures the steady state as well as the
dynamics of the process, providing an elegant perspective for construction or
analyzing problems. In light of the decomposition, a unique definition of
relative entropy is found to formally separate the effect of detailed-balance
part and breaking detailed-balance part. We find that the relative Gini entropy
production introduced in the paper is not affected by the non-detailed balance
part of the process. This property do not holds for other entropy definition in
general discrete case
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