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Hamiltonian analysis of metric-affine-R2 theory

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arXiv 2023年

作者： Glavan, Dražen Zlosnik, Tom Lin, Chunshan CEICO FZU Institute of Physics The Czech Academy of Sciences Na Slovance 1999/2 Prague 8182 21 Czech Republic Institute of Theoretical Physics and Astrophysics University of Gdańsk ul. Wita Stwosza 57 Gdańsk80-308 Poland Faculty of Physics Astronomy and Applied Computer Science Jagiellonian University ul. prof. Stanislawa Lojasiewicza 11 Kraków30-348 Poland

Determining the number of propagating degrees of freedom in metric-affine theories of gravity requires the use of Hamiltonian constraint analysis, except in some subclasses of theories. We develop the technicalities necessary for such analyses and apply them to the Weyl-invariant and projective-invariant case of metric-affine-R2 theory that is known to propagate just the graviton. This serves as a check of the formalism and a case study where we introduce appropriate ADM variables for the distortion 3-tensor tensor and its time derivatives, that will be useful when analyzing more general metric-affine theories where the physical spectrum is not known. © 2023, CC BY.

关键词： Hamiltonians

A Dual Polarization Antenna on Perpendicular Strip Line with Fractal Narrow Slit for GPS, 4G LTE, and 5G Network Applications

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A Dual Polarization Antenna on Perpendicular Strip Line with...

International Conference on Electrical Engineering/Electronics, computer, Telecommunications and Information Technology, ECTI-CON

作者： Ian Jerome Q. Santos Norakamon Wongsin Paitoon Rakluea Thinnawat Jangjing Nutyada Nantapanich Nonchanutt Chudpooti Chatree Mahatthanajatuphat Prayoot Akkaraekthalin Department of Electronics and Telecommunication Engineering Faculty of Engineering Rajamangala University of Technology Thanyaburi Thanyaburi Pathum Thani Thailand Department of Thai-German Pre-Engineering School Faculty of The College of Industrial Technology King Mongkut's University of Technology North Bangkok Bangsue Bangkok Thailand Department of Industrial Physics and Medical Instrumentation Faculty of Applied Science King Mongkut's University of Technology North Bangkok Bangsue Bangkok Thailand Department of Electrical and Computer Engineering Faculty of Engineering King Mongkut's University of Technology North Bangkok Bangsue Bangkok Thailand

ISBN: (数字)9798350381559

ISBN: (纸本)9798350381566

This article discusses the utilization of a dual polarization antenna on a perpendicular strip line, including a fractal narrow slit, for a global positioning system (GPS), 4G Long Term Evolution (LTE), and a 5G communication network. The proposed antenna consists of a perpendicular strip line that couples the electromagnetic field to a fractal narrow slit, allowing resonance at frequencies of 1.74 GHz and 2.675 GHz. Additionally, it has the capability to facilitate circular polarization for GPS applications and linear polarization for 4G&5G communication networks. The proposed antenna has an impedance characteristic of essentially 22.41% and 9.40% for S11 at frequencies of 1.74 GHz and 2.675 GHz, respectively. At 1.575 GHz, 1.74 GHz, and 2.675 GHz, the antenna's identified peak gains are approximately 2.3 dBi, 2.8 dBi and 3.86 dBi, respectively. Moreover, the proposed antenna has the capability to generate a radiation pattern that propagates in two opposing directions, enabling the efficient exploitation of both GPS and 4G&5G communication network.

关键词： Polarization 5G mobile communication Resonant frequency Fractals Resonance Telecommunications Communication networks

Non-rotational measures in the Bargmann space, and entanglement of bipartite squeezed coherent states

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arXiv 2024年

作者： Górska, K. Horzela, A. Kolaczek, D. Spisak, B.J. Szafraniec, F.H. H. Niewodniczański Institute of Nuclear Physics Polish Academy of Sciences ul.Eljasza-Radzikowskiego 152 KrakówPL 31342 Poland Department of Applied Mathematics University of Agriculture in Kraków ul. Balicka 253c Kraków30–198 Poland AGH University of Krakow Faculty of Physics and Applied Computer Science al. A. Mickiewicza 30 Krakow30-059 Poland Instytut Matematyki Uniwersytet Jagielloński ul. Lojasiewicza 6 Kraków30 348 Poland

Entanglement of bipartite squeezed states generated by holomorphic Hermite functions of two complex variables is investigated using phase-space approach based on the Wigner distribution function. Orthogonality of the holomorphic Hermite functions implies the relationship between certain real parameter associated with the non-rotational measure in the Bargmann space and the squeezing parameter. The mutual relation between squeezing and entanglement is elucidated with the help of Peres-Horodecki positive partial transpose criterion formulated in the phase-space version for continuous-variable systems. The quantitative characteristics of the entanglement is determined using the log-negativity criterion. The oscillator-like model of a two-particle quantum-mechanical system is developed to illustrate the presented findings. © 2024, CC BY.

关键词： Phase space methods

Development of the normalization method for the Jagiellonian PET scanner

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arXiv 2022年

作者： Coussat, Aurélien Krzemien, Wojciech Baran, Jakub Parzych, Szymon Faculty of Physics Astronomy and Applied Computer Science Jagiellonian University Kraków30-348 Poland Centre for Theranostics Jagiellonian University Kraków31-501 Poland High Energy Physics Division National Centre for Nuclear Research Swierk OtwockPL-05-400 Poland

This work aims at applying the theory of the component-based normalization for the Jagiellonian PET scanner, currently under development at the Jagiellonian University. In any Positron Emission Tomography acquisition, efficiency along a line-of-response can vary due to several physical and geometrical effects, leading to severe artifacts in the reconstructed image. To mitigate these effects, a normalization coefficient is applied to each line-of-response, defined as the product of several components. Specificity of the Jagiellonian PET scanner geometry is taken into account. Results obtained from GATE simulations are compared with preliminary results obtained from experimental data. © 2022, CC BY.

关键词： Positrons

Parametric resonance of gravitational waves in general scalar-tensor theories

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arXiv 2023年

作者： Cai, Yi-Fu Domènech, Guillem Ganz, Alexander Jiang, Jie Lin, Chunshan Wang, Bo Deep Space Exploration Laboratory School of Physical Sciences University of Science and Technology of China Anhui Hefei230026 China Department of Astronomy School of Astronomy and Space Science University of Science and Technology of China Anhui Hefei230026 China Institute for Theoretical Physics Leibniz University Hannover Appelstraße 2 Hannover30167 Germany Faculty of Physics Astronomy and Applied Computer Science Jagiellonian University Krakow30-348 Poland Center for Cosmological Constant Problem Pusan National University Busan46241 Korea Republic of Department of Physics Pusan National University Busan46241 Korea Republic of

Gravitational waves offer a potent mean to test the underlying theory of gravity. In general theories of gravity, such as scalar-tensor theories, one expects modifications in the friction term and the sound speed in the gravitational wave equation. In that case, rapid oscillations in such coefficients, e.g. due to an oscillating scalar field, may lead to narrow parametric resonances in the gravitational wave strain. We perform a general analysis of such possibility within DHOST theories. We use disformal transformations to find the theory space with larger resonances, within an effective field theory approach. We then apply our formalism to a non-minimally coupled ultra-light dark matter scalar field, assuming the presence of a primordial gravitational wave background, e.g., from inflation. We find that the resonant peaks in the spectral density may be detectable by forthcoming detectors such as LISA, Taiji, Einstein Telescope and Cosmic Explorer. Copyright © 2023, The Authors. All rights reserved.

关键词： Tensors

CPW-fed Monopole Antenna with 3.5/5.5 GHz Band-Notched Characteristics for Ultrawideband Applications

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CPW-fed Monopole Antenna with 3.5/5.5 GHz Band-Notched Chara...

International Symposium on Antennas and Propagation (ISAP)

作者： Nipont Tangthong Pichet Moeikham Patchadaporn Sangpet Atthakorn Jamnien Prayoot Akkaraekthalin Nonchanutt Chudpooti Deparment of Electronics and Telecommunication Engineering Faculty of Engineering Rajamangala University of Technology Thanyaburi Pathum Thani Thailand Deparment of Electrical Engineering Faculty of Engineering Rajamangala University of Technology Lanna Chiang Rai Chiang Rai Thailand KMUTNB Techno Park King Mongkut’s University of Technology North Bangkok Bangkok Thailand Deparment of Electrical and Computer Engineering Faculty of Engineering King Mongkut’s University of Technology North Bangkok Bangkok Thailand Deparment of Industrial Physics and Medical Instrumentation Faculty of Applied Science King Mongkut’s University of Technology North Bangkok Bangkok Thailand

ISBN: (数字)9798350364774

ISBN: (纸本)9798350364781

This research presents a printed ultrawideband monopole antenna designed with notches at the 3.5 GHz and 5.5 GHz frequency bands. The antenna incorporates a 50-Ω Coplanar Waveguide (CPW) feed, featuring a gradual central line and ground plane. To notch unwanted frequencies at 3.5 GHz and 5.5 GHz, an inverted triangle slot and an inverted U-shaped slot are integrated into the monopole patch. Operating across a frequency range of 2.62-12 GHz, the proposed antenna supports the UWB system while excluding the 3.22-3.62 GHz and 5.14-5.62 GHz bands. The lengths of the inverted triangle and U-shaped slots correspond to quarter and half wavelengths at 3.5 GHz and 5.5 GHz, respectively. The prototype has been fully developed and tested, showing its effectiveness in reducing Electromagnetic Interference (EMI) in WLAN/WiMAX bands.

关键词： Antenna measurements Wireless communication Slot antennas Electromagnetic interference Prototypes Ultra wideband antennas Frequency measurement Coplanar waveguides Planar waveguides Antenna radiation patterns

TOF MLEM Adaptation for the Total-Body J-PET with a Realistic Analytical System Response Matrix

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arXiv 2023年

作者： Shopa, R.Y. Baran, J. Klimaszewski, K. Krzemień, W. Raczyński, L. Wiślicki, W. Brzeziński, K. Chug, N. Coussat, A. Curceanu, C. Czerwiński, E. Dadgar, M. Dulski, K. Gajewski, J. Gajos, A. Hiesmayr, B.C. Valsan, E. Kavya Korcyl, G. Kozik, T. Kumar, D. Kaplon, L. Moskal, G. Niedźwiecki, S. Panek, D. Parzych, S. del Rio, E. Pérez Ruciński, A. Sharma, S. Shivani Silarski, M. Skurzok, M. Stępień, E. Ardebili, F. Tayefi Ardebili, K. Tayefi Moskal, P. Department of Complex Systems National Centre for Nuclear Research Otwock-Świerk Poland Faculty of Physics Astronomy and Applied Computer Science Jagiellonian University Kraków Poland Total-Body Jagiellonian-PET Laboratory Jagiellonian University Kraków Poland Center for Theranostics Jagiellonian University Kraków Poland High Energy Physics Division National Centre for Nuclear Research Otwock-Świerk Poland Institute of Nuclear Physics Polish Academy of Sciences Kraków Poland INFN Laboratori Nazionali di Frascati Frascati Italy Faculty of Physics University of Vienna Vienna Austria Faculty of Chemistry the Jagiellonian University Kraków Poland

We report a study of the original image reconstruction algorithm based on the time-of-flight maximum likelihood expectation maximisation (TOF MLEM), developed for the total-body (TB) Jagiellonian PET (J-PET) scanners. The method is applicable to generic cylindrical or modular multi-layer layouts and is extendable to multi-photon imaging. The system response matrix (SRM) is represented as a set of analytical functions, uniquely defined for each pair of plastic scintillator strips used for the detection. A realistic resolution model (RM) in detector space is derived from fitting the Monte Carlo simulated emissions and detections of annihilation photons on oblique transverse planes. Additional kernels embedded in SRM account for TOF, parallax effect and axial smearing. The algorithm was tested on datasets, simulated in GATE for the NEMA IEC and static XCAT phantoms inside a 24-module 2-layer TB J-PET. Compared to the reference TOF MLEM with none or a shift-invariant RM, an improvement was observed, as evaluated by the analysis of image quality, difference images and ground truth metrics. We also reconstructed the data with additive contributions, pre-filtered geometrically and with non-TOF scatter correction applied. Despite some deterioration, the obtained results still capitalise on the realistic RM with better edge preservation and superior ground truth metrics. The envisioned prospects of the TOF MLEM with analytical SRM include its application in multi-photon imaging and further upgrade to account for the non-collinearity, positron range and other factors. © 2023, CC BY.

关键词： Medical imaging

Toward a generative modeling analysis of CLAS exclusive 2π photoproduction

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Physical Review D 2023年第9期108卷 094030-094030页

作者： T. Alghamdi Y. Alanazi M. Battaglieri Ł. Bibrzycki A. V. Golda A. N. Hiller Blin E. L. Isupov Y. Li L. Marsicano W. Melnitchouk V. I. Mokeev G. Montaña A. Pilloni N. Sato A. P. Szczepaniak T. Vittorini Department of Computer Science Old Dominion University Norfolk Virginia 23529 USA Department of Computer Science College of Computer Science and Information Technology Al-Baha University Al-Baha Alaqiq 65779 Saudi Arabia Thomas Jefferson National Accelerator Facility Newport News Virginia 23606 USA INFN sezione di Genova I-16146 Genova Italy AGH University of Krakow Faculty of Physics and Applied Computer Science PL-30-059 Kraków Poland Faculty of Physics Lomonosov Moscow State University 119991 Moscow Russia Institute for Theoretical Physics Tübingen University D-72076 Tübingen Germany Skobeltsyn Institute of Nuclear Physics Lomonosov Moscow State University 119234 Moscow Russia CSSM and CDMPP Department of Physics University of Adelaide 5005 Australia Dipartimento di Scienze Matematiche e Informatiche Scienze Fisiche e Scienze della Terra Università degli Studi di Messina I-98166 Messina Italy INFN Sezione di Catania I-95123 Catania Italy Department of Physics Indiana University Bloomington Indiana 47405 USA Center for Exploration of Energy and Matter Indiana University Bloomington Indiana 47403 USA Università di Genova I-16146 Genova Italy

AI-supported algorithms, particularly generative models, have been successfully used in a variety of different contexts. This work employs a generative modeling approach to unfold detector effects specifically tailored for exclusive reactions that involve multiparticle final states. Our study demonstrates the preservation of correlations between kinematic variables in a multidimensional phase space. We perform a full closure test on two-pion photoproduction pseudodata generated with a realistic model in the kinematics of the Jefferson Lab CLAS g11 experiment. The overlap of different reaction mechanisms leading to the same final state associated with the CLAS detector’s nontrivial effects represents an ideal test case for AI-supported analysis. Uncertainty quantification performed via bootstrap provides an estimate of the systematic uncertainty associated with the procedure. The test demonstrates that GANs can reproduce highly correlated multidifferential cross sections even in the presence of detector-induced distortions in the training datasets, and provides a solid basis for applying the framework to real experimental data.

关键词： Hadrons Artificial neural networks

High-purity single-photon generation based on cavity QED

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arXiv 2024年

作者： Kikura, Seigo Asaoka, Rui Koashi, Masato Tokunaga, Yuuki Department of Applied Physics Graduate School of Engineering The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo113-8656 Japan Faculty of Science and Engineering Waseda University 3-4-1 Okubo Shinjuku-ku Tokyo169-8585 Japan Computer and Data Science Laboratories NTT Corporation Musashino180-8585 Japan Photon Science Center Graduate School of Engineering The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo113-8656 Japan

We propose a scheme for generating a high-purity single photon on the basis of cavity quantum electrodynamics (QED). This scheme employs an atom as a four-level system and the structure allows the suppression of the re-excitation process due to the atomic decay, which is known to significantly degrade the single-photon purity in state-of-the-art photon sources using a three-level system. Our analysis shows that the re-excitation probability arbitrarily approaches zero without sacrificing the photon generation probability when increasing the power of a driving laser between two excited states. This advantage is achievable by using current cavity-QED technologies. Our scheme can contribute to developing distributed quantum computation or quantum communication with high accuracy. Copyright © 2024, The Authors. All rights reserved.

关键词： Particle beams