Federated Generative Adversarial Learning

This work studies training generative adversarial networks under the federated learning setting. Generative adversarial networks (GANs) have achieved advancement in various real-world applications, such as image editing, style transfer, scene generations, etc. However, like other deep learning models, GANs are also suffering from data limitation problems in real cases. To boost the performance of GANs in target tasks, collecting images as many as possible from different sources becomes not only important but also essential. For example, to build a robust and accurate bio-metric verification system, huge amounts of images might be collected from surveillance cameras, and/or uploaded from cellphones by users accepting agreements. In an ideal case, utilize all those data uploaded from public and private devices for model training is straightforward. Unfortunately, in the real scenarios, this is hard due to a few reasons. At first, some data face the serious concern of leakage, and therefore it is prohibitive to upload them to a third-party server for model training; at second, the images collected by different kinds of devices, probably have distinctive biases due to various factors, $\textit{e.g.}$, collector preferences, geo-location differences, which is also known as "domain shift". To handle those problems, we propose a novel generative learning scheme utilizing a federated learning framework. Following the configuration of federated learning, we conduct model training and aggregation on one center and a group of clients. Specifically, our method learns the distributed generative models in clients, while the models trained in each client are fused into one unified and versatile model in the center. We perform extensive experiments to compare different federation strategies, and empirically examine the effectiveness of federation under different levels of parallelism and data skewness

Hyperbolic Modules of Finite Group Algebras over Finite Fields of Characteristic Two

Let $G$ be a finite group and let $F$ be a finite field of characteristic $2$. We introduce \emph{$F$-special subgroups} and \emph{$F$-special elements} of $G$. In the case where $F$ contains a $p$th primitive root of unity for each odd prime $p$ dividing the order of $G$ (e.g. it is the case once $F$ is a splitting field for all subgroups of $G$), the $F$-special elements of $G$ coincide with real elements of odd order. We prove that a symmetric $FG$-module $V$ is hyperbolic if and only if the restriction $V_D$ of $V$ to every $F$-special subgroup $D$ of $G$ is hyperbolic, and also, if and only if the characteristic polynomial on $V$ defined by every $F$-special element of $G$ is a square of a polynomial over $F$. Some immediate applications to characters, self-dual codes and Witt groups are given

Possible HH-like dibaryon states with heavy quarks

Possible $H$-like dibaryon states $\Lambda_{c}\Lambda_{c}$ and $\Lambda_{b}\Lambda_{b}$ are investigated within the framework of quark delocalization color screening model. The results show that the interaction between two $\Lambda_{c}$'s is repulsive, so it cannot be bound state by itself. However, the strong attraction in $\Sigma_{c}\Sigma_{c}$ and $\Sigma^{*}_{c}\Sigma^{*}_{c}$ channels and the strong channel coupling, due to the central interaction of one-gluon-exchange and one-pion-exchange, among $\Lambda_{c}\Lambda_{c}$, $\Sigma_{c}\Sigma_{c}$ and $\Sigma^{*}_{c}\Sigma^{*}_{c}$ push the energy of system below the threshold of $\Lambda_{c}\Lambda_{c}$ by $22$ MeV. The corresponding system $\Lambda_{b}\Lambda_{b}$ has the similar properties as that of $\Lambda_{c}\Lambda_{c}$ system, and a bound state is also possible in $\Lambda_{b}\Lambda_{b}$ system.Comment: 6 pages, 4 figures, 3 table

Investigating the excited Ωc0\Omega^{0}_{c} states through ΞcK\Xi_{c}K and Ξc′K\Xi^{'}_{c}K decay channels

Inspired by the five newly observed $\Omega^{0}_{c}$ states by the LHCb detector, we study the $\Omega_{c}^{0}$ states as the $S-$wave molecular pentaquarks with $I=0$, $J^{P}=\frac{1}{2}^{-}$, $\frac{3}{2}^{-}$, and $\frac{5}{2}^{-}$ by solving the RGM equation in the framework of chiral quark model. Both the energies and the decay widths are obtained in this work. Our results suggest that $\Omega_{c}(3119)^{0}$ can be explained as an $S-$wave resonance state of $\Xi D$ with $J^{P}=\frac{1}{2}^{-}$, and the decay channels are the $S-$wave $\Xi_{c} K$ and $\Xi^{'}_{c}K$ . Other reported $\Omega^{0}_{c}$ states cannot be obtained in our present calculation. Another $\Omega_{c}^{0}$ state with much higher mass 3533 MeV with $J^{P}=\frac{5}{2}^{-}$ is also obtained. In addition, the calculation is extended to the $\Omega_{b}^{0}$ states, similar results as that of $\Omega^{0}_{c}$ are obtained.Comment: 6 pages, 2 figure

The effect of hidden color channels on Nucleon-Nucleon interaction

This letter reports the nucleon-nucleon($NN$) interaction obtained from multi-channel, including hidden color channels, coupling quark model calculation. The results show that the hidden color channels coupling provides the intermediate range attraction which is usually assumed to be due to multi-$\pi$ or $\sigma$ meson exchange and that the short and intermediate range $NN$ interaction can be described solely by the fundamental quark-gluon degree of freedom of QCD.Comment: 5 pages, 5 figure

Interpreting Zc(3900)Z_c(3900) and Zc(4025)/Zc(4020)Z_c(4025)/Z_c(4020) as charged tetraquark states

In the framework of color flux-tube model with a four-body confinement potential, the lowest charged tetraquark states $[Qq][\bar{Q}'\bar{q}']~(Q=c,b,q=u,d,s)$ are studied by using the variational method, Gaussian expansion method. The results indicate that some compact resonance states can be formed, the states can not decay into two color singlet mesons $Q\bar{q}'$ and $\bar{Q}'q$ through the breakdown and recombination of color flux tubes but into $Q\bar{Q}'$ and $q\bar{q}'$. The four-body confinement potential is an crucial dynamical mechanism for the formation of states, The decay mechanism is similar to that of compound nucleus and therefore the states should be called "color confined, multi-quark resonance" states. The newly observed charged states $Z_c(3900)$ and $Z_c(4025)/Z_c(4020)$ can be accommodated in the color flux-tube model and can be interpreted as the $S$-wave tetraquark states $[cu][{\bar{c}\bar{d}}]$ with quantum numbers $I=1$ and $J=1$ and 2, respectively.Comment: 8 pages, no figur

Further study of the NΩN\Omega dibaryon within constituent quark models

Inspired by the discovery of the dibaryon $d^{*}$ and the experimental search of $N\Omega$ dibaryon with the STAR data, we study the strange dibaryon $N\Omega$ further in the framework of quark delocalization color screening model and chiral quark model. We have shown $N\Omega$ is a narrow resonance in $\Lambda\Xi$ D-wave scattering before. However, the $\Lambda$-$\Xi$ scattering data analysis is quite complicated. Here we calculate the low-energy $N\Omega$ scattering phase shifts, scattering length, effective range and binding energy to provide another approach of STAR data analysis. Our results show there exists an $N\Omega$ "bound" state, which can be observed by the $N$-$\Omega$ correlation analysis with RHIC and LHC data, or by the new developed automatic scanning system at J-PARC. Besides, we also find that the hidden color channel-coupling is important for the $N\Omega$ system to develop intermediate-range attraction.Comment: 7 pages, 2 figure

Theoretical study of a d∗d^{*} resonance in 3G3^{3}G_{3} partial wave of nucleon-nucleon scattering

Inspired by the recent results of the WASA-at-COSY Collaboration, in which they found a resonance pole in the coupled $^{3}D_{3}$ - $^{3}G_{3}$ partial waves as expected from the $d^{*}$ resonance hypothesis, we calculated the resonance structure in the coupled $^{3}D_{3}$ - $^{3}G_{3}$ partial wave phase shifts of nucleon-nucleon scattering in the framework of two constituent quark models: the quark delocalization color screening model and the chiral quark model. Our results show that there is a resonance $^{7}S_{3}^{\Delta\Delta}$ in the coupled $^{3}D_{3}^{NN}$ and $^{3}G_{3}^{NN}$ partial waves in both of these two models, which is in accordance with the expectation from the $d^{*}$ resonance structure. The resonance shape in the $^{3}D_{3}^{NN}$ partial wave is remarkable, whereas in the $^{3}G_{3}^{NN}$ phase shifts there is a small rise around the resonance energy. This result is in agreement with the recent experimental observations of WASA-at-COSY Collaboration.Comment: 5 pages, 3 figure

The Representation Transformation of Multiquark Wave Functions

It is shown that the representation transformations of multiquark wave functions between different coupling schemes are just the Racah coefficients of the permutation group. The transformation coefficients between the flavor-spin (FS) and the color-spin (CS) schemes are obtained. As an example, the expansion of the physical bases in terms of symmetry bases in the CS scheme are given for the interesting cases $YIJ = 201, 210, 000$.Comment: 9 pages plus 5 tables, latex, no figure

Role of weak measurements on states ordering and monogamy of quantum correlation

The information-theoretic definition of quantum correlation, e.g., quantum discord, is measurement dependent. By considering the more general quantum measurements, weak measurements, which include the projective measurement as a limiting case, we show that while weak measurements can enable one to capture more quantumness of correlation in a state, it can also induce other counterintuitive quantum effects. Specifically, we show that the general measurements with different strengths can impose different orderings for quantum correlations of some states. It can also modify the monogamous character for certain classes of states as well which may diminish the usefulness of quantum correlation as a resource in some protocols. In this sense, we say that the weak measurements play a dual role in defining quantum correlation.Comment: 6 pages, 5 figures, the final version as that published in Int. J. Theor. Phy