Some thoughts on constructing a microscopic theory with holographic degrees of freedom

Holographic principle states that the maximum entropy of a system is its boundary area in Planck units. However, such a holographic entropy cannot be realized by the conventional quantum field theory. We need a new microscopic theory which naturally possesses all the holographic degrees of freedom. In this paper, we provide some preliminary thoughts on how to construct a theory with holographic degrees of freedom. It may shed light on the understanding of quantum properties of gravity and the early stage of the universe.Comment: 6 pages, typos correcte

The utmost distance for quantum entanglement

A common viewpoint is that a particle could be quantum entangled with another particle arbitrarily far away. But in this paper we suggest that there is an utmost distance for the existence of quantum entanglement between two particles, beyond which the initial quantum entanglement would be broken by some quantum gravitational effect. The utmost distance is proposed to be $L_{QE}=\lambda^\alpha l_{p}^{1-\alpha}$, where $\lambda$ is the quantum wavelength of the particles and $l_{p}= 1.616 \times 10^{-35} m$ is the Planck length. The most probable value of the parameter $\alpha$ is $2$ or $3$. As other quantum-gravitational effects, this effect is very weak and hard to be detected in foreseeable experiment.Comment: 4 pages, 1 figure, 1 tabl

Effects of Pressure on the Electronic Structures of LaOFeP

We studied the electronic structures of LaOFeP under applied pressure using first-principles calculations. The electronic density of states at the Fermi level decreases continuously with increasing pressure. The electron branches of Fermi surfaces are rather robust to pressure, while the hole branches change significantly. Two hole surfaces shrink into small ellipsoid-like surfaces and disappear finally, at which the applied pressure is ~ 74.7 GPa. The pressure response can be understood by the band structures around the Fermi level. Comparative studies reveal that the disappearance of hole surfaces is mainly due to the compression of the FeP layer along the c-axis of unit cell.Comment: 26 pages, 9 figure

Does the bottomonium counterpart of X(3872)X(3872) exist?

A narrow line shape peak at about 10615 MeV, just above the threshold in the $B\bar B^*$ channel, which can be regarded as the signal of bottomonium counterpart of $X(3872)$, $X_b$, is predicted by using the extended Friedrichs scheme. Though a virtual state is found at about 10593 MeV in this scheme, we point out that the peak is contributed mainly by the coupling form factor, which comes from the convolution of the interaction term and meson wave functions including the one from $\chi_{b1}(4P)$, but not mainly by the virtual-state pole. In this picture, the reason why $X_b$ signal is not observed in the $\Upsilon\pi^+\pi^-$ and $\Upsilon\pi^+\pi^-\pi^0$ channels can also be understood. The $\chi_{b1}(4P)$ mass and width are found to be about 10771 MeV and 6 MeV, respectively and a dynamically generated broad resonance is also found with its mass and width at about 10672 MeV and 78 MeV, respectively. The line shapes of these two states are also affected by the form factor effect. Thus, this study also emphasizes the importance of the structure of the wave functions of high radial excitations in the analysis of the line shapes, and provides a caveat that some signals may be generated from the structures of the form factors rather than from poles.Comment: 5 pages, 3 figures; v2, the final published versio

Randomness versus specifics for word-frequency distributions

The text-length-dependence of real word-frequency distributions can be connected to the general properties of a random book. It is pointed out that this finding has strong implications, when deciding between two conceptually different views on word-frequency distributions, i.e. the specific `Zipf's-view' and the non-specific `Randomness-view', as is discussed. It is also noticed that the text-length transformation of a random book does have an exact scaling property precisely for the power-law index $\gamma=1$, as opposed to the Zipf's exponent $\gamma=2$ and the implication of this exact scaling property is discussed. However a real text has $\gamma>1$ and as a consequence $\gamma$ increases when shortening a real text. The connections to the predictions from the RGF(Random Group Formation) and to the infinite length-limit of a meta-book are also discussed. The difference between `curve-fitting' and `predicting' word-frequency distributions is stressed. It is pointed out that the question of randomness versus specifics for the distribution of outcomes in case of sufficiently complex systems has a much wider relevance than just the word-frequency example analyzed in the present work.Comment: 9 pages, 7 figure

Coherent state path integral approach to correlated electron systems with deformed Hubbard operators: from Fermi liquid to Mott insulator

In strongly correlated electron systems the constraint which prohibits the double electron occupation at local sites can be realized by either the infinite Coulomb interaction or the correlated hopping interaction described by the Hubbard operators, but they both render the conventional field theory inapplicable. Relaxing such the constraint leads to a class of correlated hopping models based on the deformed Hubbard operators which smoothly interpolate the locally free and strong coupling limits by a tunable interaction parameter $0\leq \lambda\leq 1$. Here we propose a coherent state path integral approach appropriate to the deformed Hubbard operators for {\it arbitrary} $\lambda$. It is shown that this model system exhibits the correlated Fermi liquid behavior characterized by the enhanced Wilson ratio for all $\lambda$. It is further found that in the presence of on-site Coulomb interaction a finite Mott gap appears between the upper and lower Hubbard bands, with the upper band spectral weight being heavily reduced by $\lambda$. Our approach stands in general spatial dimensions and reveals an unexpected interplay between the correlated hopping and the Coulomb repulsion.Comment: 9 pages, 5 figures (including several appendices

Comprehending Isospin breaking effects of X(3872)X(3872) in a Friedrichs-model-like scheme

Recently, we have shown that the $X(3872)$ state can be naturally generated as a bound state by incorporating the hadron interactions into the Godfrey-Isgur quark model using the Friedrichs-like model combined with the QPC model, in which the wave function for the $X(3872)$ as a combination of the bare $c\bar c$ state and the continuum states can also be obtained. Under this scheme, we now investigate the isospin breaking effect of $X(3872)$ in its decays to $J/\psi\pi^+\pi^-$ and $J/\psi\pi^+\pi^-\pi^0$. By Considering its dominant continuum parts coupling to $J/\psi\rho$ and $J/\psi\omega$ through the quark rearrangement process, one could obtain the reasonable ratio of $\mathcal{B}(X(3872)\rightarrow J/\psi\pi^+\pi^-\pi^0)/\mathcal{B}(X(3872)\rightarrow J/\psi\pi^+\pi^-)\simeq (0.58\sim 0.92)$. It is also shown that the $\bar D D^*$ invariant mass distributions in the $B\rightarrow \bar D D^* K$ decays could be understood qualitatively at the same time. This scheme may provide more insight to understand the enigmatic nature of the $X(3872)$ state.Comment: 13 pages, 4 figure

Destination Choice Game: A Spatial Interaction Theory on Human Mobility

With remarkable significance in migration prediction, global disease mitigation, urban planning and many others, an arresting challenge is to predict human mobility fluxes between any two locations. A number of methods have been proposed against the above challenge, including the gravity model, the intervening opportunity model, the radiation model, the population-weighted opportunity model, and so on. Despite their theoretical elegance, all models ignored an intuitive and important ingredient in individual decision about where to go, that is, the possible congestion on the way and the possible crowding in the destination. Here we propose a microscopic mechanism underlying mobility decisions, named destination choice game (DCG), which takes into account the crowding effects resulted from spatial interactions among individuals. In comparison with the state-of-the-art models, the present one shows more accurate prediction on mobility fluxes across wide scales from intracity trips to intercity travels, and further to internal migrations. The well-known gravity model is proved to be the equilibrium solution of a degenerated DCG neglecting the crowding effects in the destinations.Comment: 18 pages, 9 figure

The origin of light 0+0^{+} scalar resonances

We demonstrate how most of the light $J^{P}=0^{+}$ spectrum below $2.0\,\mathrm{GeV}$ and their decays can be consistently described by the unitarized quark model incorporating the chiral constraints of Adler zeros and taking SU(3) breaking effects into account. These resonances appear as poles in the complex $s$ plane in a unified picture as $q\bar{q}$ states strongly dressed by hadron loops. Through the large $N_c$ analysis, these resonances are found to naturally separate into two kinds: $\sigma, \kappa, f_0(980), a_0(980)$ are dynamically generated and run away from the real axis as $N_c$ increases, while the others move towards the $q\bar q$ seeds. In this picture, the line shape of $a_0(980)$ is produced by a broad pole below the $K\bar{K}$ threshold, and exhibits characteristics similar to the $\sigma$ and $\kappa$.Comment: 7 pages, 12 figures, Revtex4-1. Significantly revised and expanded version. The main result not change

Understanding X(3862)X(3862), X(3872)X(3872), and X(3930)X(3930) in a Friedrichs-model-like scheme

We developed a Friedrichs-model-like scheme in studying the hadron resonance phenomenology and present that the hadron resonances might be regarded as the Gamow states produced by a Hamiltonian in which the bare discrete state is described by the result of usual quark potential model and the interaction part is described by the quark pair creation model. In a one-parameter calculation, the $X(3862)$, $X(3872)$, and $X(3930)$ state could be simultaneously produced with a quite good accuracy by coupling the three P-wave states, $\chi_{c2}(2P)$, $\chi_{c1}(2P)$, $\chi_{c0}(2P)$ predicted in the Godfrey-Isgur model to the $D\bar D$, $D\bar D^{*}$, $D^*\bar D^*$ continuum states. At the same time, we predict that the $h_c(2P)$ state is at about 3902 MeV with a pole width of about 54 MeV. In this calculation, the $X(3872)$ state has a large compositeness. This scheme may shed more light on the long-standing problem about the general discrepancy between the prediction of the quark model and the observed values, and it may also provide reference for future search for the hadron resonance state.Comment: 5 pages, 1 figure; A mistake was found in the numerical calculation and the numerical results change a little. The qualitative discussion and conclusion not change