193 research outputs found
Koll\'ar's Package for Twisted Saito's S-sheaves
We generalize Koll\'ar's conjecture (including torsion freeness, injectivity
theorem, vanishing theorem and decomposition theorem) to Saito's -sheaves
twisted by a -divisor. This gives a uniform treatment for various
kinds of Koll\'ar's package in different topics in complex geometry. As a
consequence we prove Koll\'ar's package of pluricanonical bundles twisted by a
certain multiplier ideal sheaf. The method of the present paper is
-theoretic.Comment: Comments are welcom
-Dolbeault resolution of the lowest Hodge piece of a Hodge module
Let be a complex space and a pure Hodge module with strict support
. The purpose of this paper is to introduce a coherent subsheaf
of M. Saito's which is a combination of and the
multiplier ideal sheaf while constructing a resolution
of by differential forms with certain -boundary conditions.
This could be viewed as a wide generalization of MacPherson's conjecture on the
-representation of the Grauert-Riemenschneider sheaf. As applications,
various vanishing theorems for (Saito's vanishing, Kawamata-Viehweg
vanishing and some new ones like Nadel vanishing, partial vanishing) are proved
via standard differential geometrical arguments.Comment: 25 pages. Comments are welcome
Hyperbolicity of the base of an admissible family of log canonical stable minimal models
We investigate the stratified hyperbolicity properties of Birkar's moduli
stack of log canonical (lc) stable minimal models. The main technical result is
a construction of Viehweg-Zuo's system of Higgs sheaves associated with an
admissible family of lc stable minimal models, using the theory of
degenerations of Hodge structure and non-abelian Hodge theory.Comment: 34 pages. Some typos are fixed. Comments are welcom
An Improved NMS-Based Adaptive Edge Detection Method and Its FPGA Implementation
For improving the processing speed and accuracy of edge detection, an adaptive edge detection method based on improved NMS (nonmaximum suppression) was proposed in this paper. In the method, the gradient image was computed by four directional Sobel operators. Then, the gradient image was processed by using NMS method. By defining a power map function, the elements values of gradient image histogram were mapped into a wider value range. By calculating the maximal between-class variance according to the mapped histogram, the corresponding threshold was obtained as adaptive threshold value in edge detection. Finally, to be convenient for engineering application, the proposed method was realized in FPGA (Field Programmable Gate Array). The experiment results demonstrated that the proposed method was effective in edge detection and suitable for real-time application
Earth Shielding and Daily Modulation from Electrophilic Boosted Dark Particles
Boosted dark particles of astrophysical origin can lead to nonstandard
nuclear or electron recoil signals in direct detection experiments. %It has
been shown that this interpretation successfully explains the excess of keV
electron recoil events recently observed by the XENON1T experiment, and that a
daily modulation of the signal in the detector is expected. We conduct an
investigation of the daily modulation feature of a potential future signal of
this type. In particular, we perform simulations of the dark particle
interactions with electrons in atoms building up the Earth on its path to the
detector, and provide in-depth predictions for the expected daily changes in
the signal for various direct detection experiments, including XENONnT, PandaX,
and LUX-ZEPLIN.Comment: 15 pages, 12 figures, published version in PRD. For the code to
calculate the atomic ionization form factor, see
https://github.com/XueXiao-Physics/AtomIonCalc (AtomIonCalc) . For the Monte
Carlo simulation of the electrophilic dark particles traveling inside the
earth, see https://github.com/XueXiao-Physics/realEarthScatterDM
(realEarthScatterDM
Temperature-dependent structure of an intermetallic ErPdSi single crystal: A combined synchrotron and in-house X-ray diffraction study
We have grown intermetallic ErPdSi single crystals employing
laser-diodes with the floating-zone method. The temperature-dependent
crystallography was determined using synchrotron and in-house X-ray powder
diffraction measurements from 20 to 500 K. The diffraction patterns fit well
with the tetragonal 4/ space group (No. 139) with two chemical formulas
within one unit cell. Our synchrotron X-ray powder diffraction study shows that
the refined lattice constants are = 4.10320(2) {\AA}, = 9.88393(5)
{\AA} at 298 K and = 4.11737(2) {\AA}, = 9.88143(5) {\AA} at 500 K,
resulting in the unit-cell volume = 166.408(1) {\AA} (298 K) and
167.517(2) {\AA} (500 K). In the whole studied temperature range, we did
not find any structural phase transition. Upon cooling, the lattice constants a
and c are shortened and elongated, respectively.Comment: 5 Figures, 4 Table
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