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Microlensing effects of wormholes associated to blackhole spacetimes

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physics of the Dark Universe 2023年 41卷

作者： Gao, Ke Liu, Lei-Hua Zhu, Mian Department of Physics College of Physics Mechanical and Electrical Engineering Jishou University Jishou 416000 China Department of Physics The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong Jockey Club Institute for Advanced Study The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong Faculty of Physics Astronomy and Applied Computer Science Jagiellonian University Krakow 30-348 Poland

In this paper, we investigate the microlensing effects of wormholes associated to black hole spacetimes. Specifically, we work on three typical wormholes (WH): Schwarzschild WH, Kerr WH, and RN WH, as well as their blackhole correspondences. We evaluate the deflection angle upon the second order under weak field approximation using Gauss–Bonnet theorem. Then, we study their magnification with numerics. We find that a Kerr WH could lead to multi peaks in the magnification with certain parameters in the prograde case, while a Kerr BH predicts one peak. Therefore, the multi-peak feature of can be used to distinguish the Kerr WH from other compact objects. We also find that the magnification of RN BH will be one peak compared to RN WH, in which the magnification of RN WH is negative in some situations. For other cases, the behavior of magnification from wormholes and their corresponding blackholes is similar. Our result may shed new light on exploring compact objects through the microlensing effect. © 2023 Elsevier B.V.

关键词： Lensing effects Wormhole

Structural investigation of the liquid crystalline phases of three homologues from the nOS5 series (n = 9, 10, 11) by X-ray diffraction

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arXiv 2024年

作者： Deptuch, Aleksandra Sęk, Bartosz Lalik, Sebastian Ossowska-Chruściel, Miroslawa D. Chruściel, Janusz Marzec, Monika Institute of Nuclear Physics Polish Academy of Sciences Radzikowskiego 152 KrakówPL-31342 Poland Faculty of Physics and Applied Computer Science AGH University of Kraków Reymonta 19 KrakówPL-30059 Poland Institute of Physics Jagiellonian University Lojasiewicza 11 KrakówPL-30348 Poland Institute of Chemistry Siedlce University of Natural Sciences and Humanities 3 Maja 54 SiedlcePL-08110 Poland

Polarizing optical microscopy and differential scanning calorimetry are used to determine the phase sequence of three liquid crystalline 4-pentylphenyl-4’-n-alkyloxythiobenzoates with n = 9, 10, 11. The X-ray diffraction method is applied for structural characterization of the liquid crystalline phases. The smectic layer spacing, tilt angle, average distance between the long axes of molecules and correlation length of the short-range order are determined as a function of temperature. For the crystal-like smectic phases with the hexagonal or herring-bone packing, the unit cell parameters are obtained. The presence of the tilted hexagonal phase for n = 10, 11 and tilted herring-bone phase for n = 9, 10 is indicated, although the direction of the tilt cannot be determined. © 2024, CC BY.

关键词： Bone

A Portable 3D-Printed Dielectric Lens Antennas for Liquid-Mixture Characterization

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A Portable 3D-Printed Dielectric Lens Antennas for Liquid-Mi...

International Symposium on Antennas and Propagation (ISAP)

作者： Patchadaporn Sangpet Prayoot Akkaraekthalin Wanwisa Thaiwirot Nutapong Somjit Sukanya Chudpooti Nonchanutt Chudpooti Department of Electrical and Computer Engineering Faculty of Engineering King Mongkut’s University of Technology North Bangkok Bangkok Thailand School of Electronic and Electrical Engineering University of Leeds Leeds United Kingdom Department of Industrial Physics and Medical Instrumentation Faculty of Applied Science King Mongkut’s University of Technology North Bangkok Bangkok Thailand

The Fused Deposition Modeling (FDM) method is utilized in this research to present dielectric lens antennas that were 3D printed. The ultra-wideband (UWB) stub antenna’s antenna characteristic is intended to be improved by the 3D-printed dielectric lens antennas. The proportion of ethanol in the liquid mixture sample is categorized using the transmission-line measuring technique. The device-under-test (DUT) is placed between two 3D-printed dielectric lens antennas. The glass bottle is filled with a 100-ml liquid sample and covered with a plastic cap. The 3D EM Simulation CST Studio is used to optimize the 10 mm gap between the dielectric lens antennas and the DUT. Six concentrations of the ethanol/water mixture, such as empty, 60%, 65%, 70%, and 80%, are measured to examine the measurement system. The measurement outcomes indicate the various S21 (transmission coefficient) levels between 9 GHz and 11 GHz. According to the trend of the suggested system, the level of the transmission coefficient, S21, will change downward when the proportion of ethanol is increased. Several better advantages, such as a non-destructive method, non-contact measurement, and support with a real-time monitoring system, are provided by the transmission-line measuring methodology using 3D-printed dielectric lens antennas.

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Energy dependence of proton-proton elastic scattering at large momentum transfer

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arXiv 2023年

作者： Ferreira, Erasmo Kohara, Anderson Kendi Instituto de Física Universidade Federal do Rio de Janeiro C.P. 68528 Rio de Janeiro Rio de Janeiro21945-970 Brazil AGH University Of Science and Technology Faculty of Physics and Applied Computer Science Mickiewicza 30 Kraków30-059 Poland

The measurements of proton-proton elastic scattering for large momentum transfer at energies in the range ≈ 20 to 60 GeV show a simple behaviour of form dσ/dt ≈ const |t|−8, apparently with no energy dependence. In the present work detailed analysis of the data shows a decrease of the magnitude of the tail with the energy, still with preservation of the power |t|−8. The analysis allows the definition of a band for the energy dependence of the amplitude with central line A(√s) = 0.389 log (100)/ log √s GeV6 . The rate of decrease describes well the data at the distant energy √s = 13 TeV, with reduction of the cross section by a factor 5.71. This result gives prediction for new experiments at high energies, and opens important question for theoretical investigation. Copyright © 2023, The Authors. All rights reserved.

关键词： Elastic scattering

Nuclear Track Quantification in Cr-39 Detectors Using Deep Learning

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SSRN

SSRN 2024年

作者： Mohamed, Soheir E. Alahmari, Saeed Khan, Arshad Al-Naggar, Tayseer I. Ashraf, O. Al-Qahtani, Suha Al-Sari, Rahaf Salem Al-Yami, Ghda Sulsiman Al-Amer, Noura Ail Al-Yami, Yosra Ail ALGhabar, Razan Hadi Abdalla, Ayman M. Department of Radiological Sciences Applied Medical Sciences College Najran University Najran Saudi Arabia College of Computer Science and Information Systems Najran University Najran Saudi Arabia Department of Physics Faculty of Arts and Sciences Najran University Najran Saudi Arabia Unit of Radiation Protection Najran University Najran1101 Saudi Arabia Najran University Najran11001 Saudi Arabia Physics Department Faculty of Education Ain Shams University Cairo11341 Egypt

This study explores the utilization of Artificial Intelligence (AI) in optimizing alpha particles detection using CR-39 nuclear track detectors. This study compares the performance of the Cellpose AI-based software with the traditional manual method employing Image J. Through a comprehensive analysis of diameter, critical angle, and efficiency at different etching times and temperatures, the study investigates the potential of AI in enhancing a-particles detection. The results demonstrate a promising synergy between AI and manual measurements, emphasizing the advantages of speed and standardization offered by AI. The finding highlights the superior performance of the Cellpose method compared to Image J in terms of efficiency and critical angle. At an etching temperature of 85°C and a-particles energy of 2.2 MeV, the Cellpose method outperforms Image J, recording an efficiency of 93.32% compared to Image J's lower efficiency of 82.81%. These results emphasize the advantages of utilizing the Cellpose method for a-particles detection, offering higher efficiency measurements than Image J. However, variations in diameter measurements at lower a-particles energy and shorter etching times indicate the need for continuous refinement and training of the AI model to ensure accuracy under diverse conditions. © 2024, The Authors. All rights reserved.

关键词： Alpha particles

Scalable Method for Horizontal-Dipping Electrodeposition of Platinum Nanoparticles in Application to Dye-Sensitized Solar Cells

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SSRN

SSRN 2023年

作者： Augustowski, Dariusz Michalik, Maciej Wilgocki-Ślęzak, Jakub Kwaśnicki, Pawel Rysz, Jakub Department of Advanced Materials Engineering Faculty of Physics Astronomy and Applied Computer Science Jagiellonian University Lojasiewicza 11 Cracow30-348 Poland Research & Development Centre for Photovoltaics ML System S.A. Zaczernie 190G Zaczernie36-062 Poland

Up-scaling is still a great opportunity to achieve in the third generation of solar cells. Described in this article novel method combines the electrodeposition with roll-to-roll technique and may be useful in future mass production of dye-sensitized solar cells. The results obtained showed that large areas of conductive substrates can easily be covered with catalytically active platinum nanoparticles with a small amount of aqueous solution of the platinum precursor salt sliding over a substrate. The surface coverage could be controlled by applied current density, which has a direct impact on the catalytic properties of the substrate. The electrodeposition seems to be cheap, eco-friendly, and time-saving if compared with commonly used screen-printing methods. Secondarily, the electrodeposited nanoparticles exhibited even higher electrocatalytic performance in cyclic voltammetry measurements. Dye-sensitized solar cells utilizing cathodes with platinum nanoparticles prepared with different deposition currents showed efficiency in the range of 4.84-5.45%, while the referential cells with screen-printed an average efficiency of 5.14%. © 2023, The Authors. All rights reserved.

关键词： Scalability

Electric dipole spin resonance in single and two electron quantum dot defined in two-dimensional electron gas at the SrTiO3/LaAlO3 interface.

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arXiv 2023年

作者： Szafran, B. Zegrodnik, M. Nowak, M.P. Citro, R. Wójcik, P. AGH University of Krakow Faculty of Physics and Applied Computer Science Al. Mickiewicza 30 Krakow30-059 Poland AGH University of Krakow Academic Centre for Materials and Nanotechnology Al. Mickiewicza 30 Krakow30-059 Poland Fisciano132 Italy

We investigate the energy spectrum of a single and two electron quantum dot (QD) embedded in two dimensional electron gas at the interface between SrTiO3 and LaAlO3, in the presence of the external magnetic field. For this purpose the three band model of 3d-electrons defined on the square lattice of Ti ions was utilized. We demonstrate that, for the weak parabolic confinement potential, the low energy spectrum is sufficiently well described by the effective Hamiltonian reduced to the one dxy orbital with the spin-orbit interaction originating from the coupling to the dxz, dyz bands. This is not the case for stronger confinement where contribution of the states related to the dxz/yz orbital is relevant. Based on the time depended calculations we discuss in details the manipulation of the electron spin in QD by external AC voltages, in the context of the electric dipole spin resonance. The allowed and forbidden transitions are discussed in details with respect to the parity selection rule. Our calculations show that for a single electron QD the spin-flip in the ground-state has a character of a Rabi resonance while for two electrons the singlet-triplet transition is forbidden by the parity symmetry. For the two electrons QD, we demonstrate that the spin-flip transition can still be accomplished via a second-order, two-photon process that has a two-state Rabi character for low AC field amplitude. The violation of the parity symmetry on the spin-flip transitions is also analyzed. © 2023, CC BY.

关键词： Lanthanum compounds

Digital few-mode fiber multiplexer using multiplane light conversion

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Digital few-mode fiber multiplexer using multiplane light co...

IEEE Photonics Conference (IPC)

作者： Dennis Pohle Fabio A. Barbosa Filipe M. Ferreira Stefan Rothe Juergen W Czarske Chair of Measurement and Sensor System Technique Faculty of Electrical and Computer Engineering TU Dresden Dresden Germany Department of Electronic and Electrical Engineering Optical Networks Group University College London United Kingdom Institute of Applied Physics School of Science TU Dresden Dresden Germany

We propose an all-optical data-driven technique for space division multiplexing in few-mode fibers. A digital twin was realized by multiplane light conversion and neural networks. It is promising for a digitally progr...

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Machine-Learned Models for Power Magnetic Material Characteristics

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arXiv 2023年

作者： Leszczyński, Pawel Kutorasiński, Kamil Szewczyk, Marcin Pawlowski, Jaroslaw Division of Power Apparatus Protection and Control Faculty of Electrical Engineering Electrical Power Engineering Institute Warsaw University of Technology Koszykowa 75 St. Warszawa00-662 Poland Department of Condensed Matter Physics Faculty of Physics and Applied Computer Science AGH University of Krakow Reymonta 19 St. Kraków30-059 Poland Institute of Theoretical Physics Wroclaw University of Science and Technology Wyb. Wyspiańskiego 27 St. Wroclaw50-370 Poland

We present a general framework for modeling power magnetic materials characteristics using deep neural networks. Magnetic materials represented by multidimensional characteristics (that mimic measurements) are used to train the neural autoencoder model in an unsupervised manner. The encoder is trying to predict the material parameters of a theoretical model, which is then used in a decoder part. The decoder, using the predicted parameters, reconstructs the input characteristics. The neural model is trained to capture a synthetically generated set of characteristics that can cover a broad range of material behaviors, leading to a model that can generalize on the underlying physics rather than just optimize the model parameters for a single measurement. After setting up the model, we prove its usefulness in the complex problem of modeling magnetic materials in the frequency and current (out-of-linear range) domains simultaneously, for which we use measured characteristics obtained for frequency up to 10 MHz and H-field up to saturation. Copyright © 2023, The Authors. All rights reserved.

关键词： Deep neural networks