Pointwise estimates for the Bergman kernel of the weighted Fock space

We prove upper pointwise estimates for the Bergman kernel of the weighted Fock space of entire functions in $L^2(e^{-2\phi})$ where $\phi$ is a subharmonic function with $\Delta \phi$ a doubling measure. We derive estimates for the canonical solution operator to the inhomogeneous Cauchy-Riemann equation and we characterize the compactness of this operator in terms of $\Delta \phi$

Shakura-Sunyaev Disk Can Smoothly Match Advection-Dominated Accretion Flow

We use the standard Runge-Kutta method to solve the set of basic equations describing black hole accretion flows composed of two-temperature plasma. We do not invoke any extra energy transport mechanism such as thermal conduction and do not specify any ad hoc outer boundary condition for the advection-dominated accretion flow (ADAF) solution. We find that in the case of high viscosity and non-zero radiative cooling, the ADAF solution can have an asymptotic approach to the Shakura-Sunyaev disk (SSD) solution, and the SSD-ADAF transition radius is close to the central black hole. Our results further prove the mechanism of thermal instability-triggered SSD-ADAF transition suggested previously by Takeuchi & Mineshige and Gu & Lu.Comment: 10 pages, 2 figures, accepted for publication in ApJ Letter

Critical frontier for the Potts and percolation models on triangular-type and kagome-type lattices II: Numerical analysis

In a recent paper (arXiv:0911.2514), one of us (FYW) considered the Potts model and bond and site percolation on two general classes of two-dimensional lattices, the triangular-type and kagome-type lattices, and obtained closed-form expressions for the critical frontier with applications to various lattice models. For the triangular-type lattices Wu's result is exact, and for the kagome-type lattices Wu's expression is under a homogeneity assumption. The purpose of the present paper is two-fold: First, an essential step in Wu's analysis is the derivation of lattice-dependent constants $A, B, C$ for various lattice models, a process which can be tedious. We present here a derivation of these constants for subnet networks using a computer algorithm. Secondly, by means of a finite-size scaling analysis based on numerical transfer matrix calculations, we deduce critical properties and critical thresholds of various models and assess the accuracy of the homogeneity assumption. Specifically, we analyze the $q$-state Potts model and the bond percolation on the 3-12 and kagome-type subnet lattices $(n\times n):(n\times n)$, $n\leq 4$, for which the exact solution is not known. To calibrate the accuracy of the finite-size procedure, we apply the same numerical analysis to models for which the exact critical frontiers are known. The comparison of numerical and exact results shows that our numerical determination of critical thresholds is accurate to 7 or 8 significant digits. This in turn infers that the homogeneity assumption determines critical frontiers with an accuracy of 5 decimal places or higher. Finally, we also obtained the exact percolation thresholds for site percolation on kagome-type subnet lattices $(1\times 1):(n\times n)$ for $1\leq n \leq 6$.Comment: 31 pages,8 figure

Studies of Thermally Unstable Accretion Disks around Black Holes with Adaptive Pseudo-Spectral Domain Decomposition Method I. Limit-Cycle Behavior in the Case of Moderate Viscosity

We present a numerical method for spatially 1.5-dimensional and time-dependent studies of accretion disks around black holes, that is originated from a combination of the standard pseudo-spectral method and the adaptive domain decomposition method existing in the literature, but with a number of improvements in both the numerical and physical senses. In particular, we introduce a new treatment for the connection at the interfaces of decomposed subdomains, construct an adaptive function for the mapping between the Chebyshev-Gauss-Lobatto collocation points and the physical collocation points in each subdomain, and modify the over-simplified 1-dimensional basic equations of accretion flows to account for the effects of viscous stresses in both the azimuthal and radial directions. Our method is verified by reproducing the best results obtained previously by Szuszkiewicz & Miller on the limit-cycle behavior of thermally unstable accretion disks with moderate viscosity. A new finding is that, according to our computations, the Bernoulli function of the matter in such disks is always and everywhere negative, so that outflows are unlikely to originate from these disks. We are encouraged to study the more difficult case of thermally unstable accretion disks with strong viscosity, and wish to report our results in a subsequent paper.Comment: 29 pages, 8 figures, accepted by Ap

Ultraporous Electron-Depleted ZnO Nanoparticle Networks for Highly Sensitive Portable Visible-Blind UV Photodetectors

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. A hierarchical nano- and microstructured morphology for visible-blind UV photodetectors is developed, which provides record-high milliampere photocurrents, nanoampere dark currents, and excellent selectivity to ultralow UV light intensities. This is a significant step toward the integration of high-performance UV photodetectors in wearable devices

Cosmological constraints from Type I radio-loud quasars

We obtain a new sample of 1192 Type I quasars with the UV-optical, radio and X-ray wavebands coverage by combining \citet{Huang2022} and other matching data of SDSS-DR16 with FIRST, XMM-Newton, and Chandra Source Catalog, and a sample of 407 flat-spectrum radio-loud quasars (FSRLQs) of blazars from the Roma-BZCAT, which can be used to investigate their multi-band luminosity correlations and measure the luminosity distances of these Type I radio-loud quasars (RLQs) samples. We check the correlation between X-ray, UV-optical, and radio luminosity for various groupings of radio-quiet quasars (RQQs) and RLQs by parameterizing X-ray luminosity as a sole function of UV-optical or radio luminosity and as a joint function of UV-optical radio luminosity, which also can be employed to determine these cosmological distances. By Bayesian information criterion (BIC), the data suggest that the X-ray luminosity of RQQs is indirectly correlative with radio luminosity because of the connection between UV-optical and radio luminosity. But for RLQs, the X-Ray luminosity is directly related to radio luminosity, and the correlations between X-ray, optical/UV, and radio luminosity increase with the ratio of monochromatic luminosities logR. Meanwhile, we compare the results from RLQs with different UV-optical power law index ${\Gamma _{UV}}$, the goodness of fit for RLQs with ${\Gamma _{UV}}\le 1.6$ seems to be better. Finally, we apply a combination of Type I RLQs and SN Ia Pantheon to verify the nature of dark energy concerning whether or not its density deviates from the constant, and give the statistical results.Comment: arXiv admin note: text overlap with arXiv:2207.0839

Observation of Fermi-energy dependent unitary impurity resonances in a strong topological insulator Bi2Se3 with scanning tunneling spectroscopy

Scanning tunneling spectroscopic studies of Bi2Se3 epitaxial films on Si (111) substrates reveal highly localized unitary impurity resonances associated with non-magnetic quantum impurities. The strength of the resonances depends on the energy difference between the Fermi level ({E_F}) and the Dirac point ({E_D}) and diverges as {E_F} approaches {E_D}. The Dirac-cone surface state of the host recovers within ~ 2{\AA} spatial distance from impurities, suggesting robust topological protection of the surface state of topological insulators against high-density impurities that preserve time reversal symmetry.Comment: 6 pages, 6 figures. Accepted for fast-track publication in Solid State Communications (2012

Transverse momentum dependence in the perturbative calculation of pion form factor

By reanalysing transverse momentum dependence in the perturbative calculation of pion form factor an improved expression of pion form factor which takes into account the transverse momentum dependenc in hard scattering amplitude and intrinsic transverse momentum dependence associated with pion wave functions is given to leading order, which is available for momentum transfers of the order of a few GeV as well as for $Q \to \infty$. Our scheme can be extended to evaluate the contributions to the pion form factor beyond leading order.Comment: 13 pages in LaTeX, plus 3 Postscript figure

Seismic Behaviour of Multistorey Steel Framed Tall Buildings Using Intentionally Eccentric Braces

Braces with intentional eccentricity (BIE) are recently proposed to improve the seismic behaviour of conventional buckling braces (CBBs) by inserting intentional eccentricity along the brace length. Due to this eccentricity and the resultant bending moment, the BIE bends uniformly from small storey drifts and moves smoothly into the postbuckling behaviour under compression and sustains trilinear behaviour under tension. This behaviour delays the appearance of midlength local buckling which causes unstable energy dissipation. BIEs have a desirable postyielding stiffness which results in stable energy dissipation during cyclic loading and are capable of dissipating energy during low-intensity earthquakes. The seismic behaviour of structures with BIEs for use in buildings has not yet been investigated, specifically in tall buildings. Therefore, this study concentrates on investigating the seismic behaviour of tall buildings equipped with BIEs that uses a 3-dimensional (3D) finite element model in ETABS. In the first step, a 20-storey structure is designed using both eccentric brace frame (EBF) and BIE system and their seismic performance under the TABAS earthquake record is compared. In the second step, the seismic performance of a 25-storey irregular structure is assessed to evaluate the efficiency of the BIE system in irregular structures. Results show the desirable performance and energy dissipation capacity of the BIE system but it also shows large out-of-plane deformation in some cases