The European Physical Journal Plus最新文献_第4页

Correction: Periodic solitons of generalized coupled nonlinear Schrödinger equations with variable coefficients 更正：具有可变系数的广义耦合非线性薛定谔方程的周期孤子

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2024-11-06 DOI: 10.1140/epjp/s13360-024-05693-z

W. Yang, X. P. Cheng

引用次数: 0

Optimization of the positron emission tomography image resolution by using quantum entanglement concept 利用量子纠缠概念优化正电子发射断层扫描图像分辨率

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2024-11-06 DOI: 10.1140/epjp/s13360-024-05776-x

H. Eslami, M. Mohamadian

{"title":"Optimization of the positron emission tomography image resolution by using quantum entanglement concept","authors":"H. Eslami, M. Mohamadian","doi":"10.1140/epjp/s13360-024-05776-x","DOIUrl":"10.1140/epjp/s13360-024-05776-x","url":null,"abstract":"<div>The application of quantum entanglement in the analysis of photons in PET imaging systems has the potential to significantly improve image quality. By acquiring additional information beyond the conventional PET system data, the polarization of coincidence photons reaching the detectors can optimally separate correct and incorrect received data. Since these photons are entangled, measuring their polarization can provide new information about related photon pairs, or true events. In this research, we demonstrate the potential for using the polarization of entangled photons to improve the image quality of PET imaging systems. We first investigate the theory of Compton scattering of 511 keV gamma photons resulting from positron annihilation using the GEANT4 object-oriented tool. Next, we survey the possibility of using quantum entanglement in a Compton PET system. We then develop new source code in the GATE program to design a new system capable of detecting the polarization of 511 keV gamma photons resulting from positron annihilation, which was not previously possible in this software. This adds a new feature to the GAET software. Finally, we compare the reconstructed images from the new proposed system and conventional PET systems, illustrating a significant enhancement in image quality.</div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"139 11","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Electromagnetic properties of (Omega _{c}^0) resonances via light-cone QCD 通过光锥 QCD 实现（Omega _{c}^0）共振的电磁特性

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2024-11-06 DOI: 10.1140/epjp/s13360-024-05779-8

Ulaş Özdem

引用次数: 0

Limit residual function method and applications to PDE models 极限残差函数法及其在 PDE 模型中的应用

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2024-11-05 DOI: 10.1140/epjp/s13360-024-05762-3

Ahmad El-Ajou, Aliaa Burqan

引用次数: 0

Bright and dark sinks-type solitons for the generalized nonlinear Schrödinger equation in polynomial potential in the presence of external source 存在外部源的多项式势中广义非线性薛定谔方程的明暗汇型孤子

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2024-11-05 DOI: 10.1140/epjp/s13360-024-05770-3

Guissiang Thomas, Alexis Paldou Yaya, Alim, Alidou Mohamadou

引用次数: 0

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2024-11-05 DOI: 10.1140/epjp/s13360-024-05774-z

A. K. Rao, B. Chauhan, R. P. Malik

{"title":"BRST and related superfield approach to a few interesting models of point particles and a model of bosonic string: a brief review","authors":"A. K. Rao, B. Chauhan, R. P. Malik","doi":"10.1140/epjp/s13360-024-05774-z","DOIUrl":"10.1140/epjp/s13360-024-05774-z","url":null,"abstract":"<div>In this brief review-cum-research article, we discuss a few key aspects of the off-shell nilpotent (anti-)BRST symmetry transformations, Curci–Ferrari (CF)-type restriction(s), coupled Lagrangians/Lagrangian densities, etc., for the 1D diffeomorphism (i.e., reparameterization) invariant models of (i) a non-relativistic and non-SUSY free particle, (ii) a scalar (i.e., non-SUSY) relativistic free particle, (iii) a spinning (i.e., SUSY) relativistic free particle, and (iv) a 2D diffeomorphism invariant model of a specific bosonic string theory within the framework of BRST and related supervariable/superfield approach. We take up a new 1D diffeomorphism invariant model of an interacting scalar relativistic particle with the electromagnetic field. The latter is treated as a constant background variable and is, therefore, independent of the evolution parameter. We show that the universal nature of the CF-type restriction is maintained in the case of this new model, too. We exploit the modified Bonora–Tonin supervariable/superfield approach (MBTSA) to BRST formalism in the context of the 1D and 2D diffeomorphism invariant theories to prove the universal nature of the CF-type restriction(s). We further demonstrate that the 1D diffeomorphism invariant models of all kinds of particles are described by the singular Lagrangians. This singular nature has, to the best of our knowledge, not been explicitly shown elsewhere. Thus, these 1D models also respect the gauge symmetry transformations which are generated by the first-class constraints that exist on them. The equivalence of the 1D diffeomorphism and gauge symmetries is also established under specific conditions.</div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"139 11","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Discrete-time quantum walks in qudit systems 量子系统中的离散时间量子行走

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2024-11-05 DOI: 10.1140/epjp/s13360-024-05751-6

Amit Saha, Debasri Saha, Amlan Chakrabarti

{"title":"Discrete-time quantum walks in qudit systems","authors":"Amit Saha, Debasri Saha, Amlan Chakrabarti","doi":"10.1140/epjp/s13360-024-05751-6","DOIUrl":"10.1140/epjp/s13360-024-05751-6","url":null,"abstract":"<div>Quantum walks contribute significantly to developing quantum algorithms and quantum simulations. Here, we introduce a first of its kind one-dimensional quantum walk in the d-dimensional quantum domain, where (d>2), and show its equivalence for circuit realization in an arbitrary finite-dimensional quantum logic for utilizing the advantage of larger state space, which helps to reduce the run-time of the quantum walks as compared to the conventional binary quantum systems. We provide efficient quantum circuits for the implementation of discrete-time quantum walks (DTQW) in one-dimensional position space in any finite-dimensional quantum system when the dimension is odd using an appropriate logical mapping of the position space on which a walker evolves onto the multi-qudit states. With example circuits for various qudit state spaces, we also explore scalability in terms of n-qudit d-ary quantum systems. Further, the extension of one-dimensional DTQW to d-dimensional DTQW using 2d-dimensional coin space on d-dimensional lattice has been studied, where (dge 2). Thereafter, the circuit design for the implementation of scalable d-dimensional DTQW in d-ary quantum systems has been portrayed. Lastly, we exhibit the circuit design for the implementation of DTQW using different coins on various search spaces.</div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"139 11","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Finite-sized one-dimensional lazy random walks 有限大小的一维懒惰随机游走

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2024-11-04 DOI: 10.1140/epjp/s13360-024-05759-y

M. Maneesh Kumar, K. Manikandan, R. Sankaranarayanan

{"title":"Finite-sized one-dimensional lazy random walks","authors":"M. Maneesh Kumar, K. Manikandan, R. Sankaranarayanan","doi":"10.1140/epjp/s13360-024-05759-y","DOIUrl":"10.1140/epjp/s13360-024-05759-y","url":null,"abstract":"<div>Random walks are fundamental models for describing stochastic processes, where a particle or agent traverses along a trajectory as per the available degrees of freedom, and respecting the constraints in the system. In contrast to traditional random walks, the lazy random walks introduce a finite “resting” probability, allowing the particle to remain at its current location with a certain likelihood, rather than always hopping to adjacent sites. In this study, we explore the behavior of a lazy random walker moving across lattice sites with periodic boundary conditions, taking discrete steps in unit time intervals. We focus on the mixing time, that is, the time interval required for the probability distribution of the walker’s position to spread out across all lattice sites uniformly. Our analysis employs two complementary methods: first, we transform the problem into a solvable eigenvalue framework to derive numerical insights into the mixing time; and in our second approach, we employ a probabilistic perspective that corroborates the numerical results. This dual methodology not only provides a comprehensive understanding of the relationship between mixing time and the number of lattice sites but also offers novel insights into how lazy random walks behave under periodic boundary conditions. The integration of these techniques significantly advances the current understanding of lazy random walks, distinguishing this work from prior studies on regular random walks. Our findings have broad implications for stochastic processes with delayed motion dynamics, thereby paving the way for further theoretical and applied research in this domain.</div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"139 11","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142579343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Closed-form solution for a mathematical extension of the multi-term fractional Bateman equations via Mikusiński operational method 通过米库辛斯基运算法的多期分数贝特曼方程数学扩展的闭式解法

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2024-11-04 DOI: 10.1140/epjp/s13360-024-05772-1

Marc Jornet

引用次数: 0

Stability and Hopf bifurcation of a HBV infection model with capsids and CTL immune response delay 带有囊壳和 CTL 免疫反应延迟的 HBV 感染模型的稳定性和霍普夫分叉

IF 2.8 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2024-11-04 DOI: 10.1140/epjp/s13360-024-05764-1

Chong Chen, Yinggao Zhou, Zhijian Ye, Mengze Gu

{"title":"Stability and Hopf bifurcation of a HBV infection model with capsids and CTL immune response delay","authors":"Chong Chen, Yinggao Zhou, Zhijian Ye, Mengze Gu","doi":"10.1140/epjp/s13360-024-05764-1","DOIUrl":"10.1140/epjp/s13360-024-05764-1","url":null,"abstract":"<div>In this paper, an in-host HBV model with two infection routes including cell-virus infection and cell-cell infection, intracellular delay (tau _1), virus replication delay (tau _2) and CTL immune response delay (tau _3) are investigated. Firstly, the positivity and boundedness of all solutions for the model with nonnegative initial values have been established. Next, two key parameters with significant biological importance, the virus reproductive number (R_0) and the CTL immune reproductive number (R_1), are derived. Subsequently, the stability of equilibria is analyzed by constructing appropriate Lyapunov functionals and applying LaSalle’s invariance principle. The results indicate that intracellular delay (tau _1) and virus replication delay (tau _2) do not affect the stability of the three equilibria. However, a positive CTL immune response delay (tau _3) can lead to stability switches at the endemic equilibrium. By treating the CTL immune response delay as a bifurcation parameter, certain conditions for these stability switches are determined. It is concluded that as the CTL immune response delay increases, the endemic equilibrium becomes unstable, resulting in a Hopf bifurcation in the system. Finally, numerical simulations further validate the theoretical findings.</div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"139 11","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0