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THRESHOLD DYNAMICS FOR THE 3d RADIAL NLS WITH COMBINED NONLINEARITY

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arXiv 2023年

作者： Ardila, Alex H. Murphy, Jason Zheng, Jiqiang Department of Mathematics Universidade Federal de Minas Gerais ICEx-UFMG CEP MG 30123-970 Brazil Department of Mathematics & Statistics Missouri University of Science & Technology RollaMO United States Institute of Applied Physics and Computational Mathematics Beijing100088 China

We consider the nonlinear Schrödinger equation with focusing quintic and defocusing cubic nonlinearity in three space dimensions: (i∂t + ∆)u = |u|2u − |u|4u. In [18, 23], the authors classified the dynamics of solutions under the energy constraint E(u) c(W), where W is the quintic NLS ground state and Ec is the quintic NLS energy. In this work we classify the dynamics of H1 solutions at the threshold E(u) = Ec(W). Copyright © 2023, The Authors. All rights reserved.

关键词： Ground state

EVERY FINITE SET OF NATURAL NUMBERS IS REALIZABLE AS ALGEBRAIC PERIODS OF A MORSE–SMALE DIFFEOMORPHISM

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arXiv 2024年

作者： Graff, Grzegorz Marzantowicz, Wac Law Michalak, Lukasz Patryk Myszkowski, Adrian Faculty of Applied Physics and Mathematics Gdańsk University of Technology Narutowicza 11/12 Gdańsk80-233 Poland Faculty of Mathematics and Computer Science Adam Mickiewicz University of Poznań ul. Uniwersytetu Poznańskiego 4 Poznań61-614 Poland Institute of Mathematics Physics and Mechanics Jadranska 19 LjubljanaSI-1000 Slovenia Independent Researcher

A given self-map f: M → M of a compact manifold determines the sequence {L(fn)}∞n=1, of the Lefschetz numbers of its iterations. We consider its dual sequence {an(f)}∞n=1 given by the Möbius inversion formula. The set AP(f) = {n ∈ N: an(f) ≠ 0} is called the set of algebraic periods. We solve an open problem existing in literature by showing that for every finite subset A of natural numbers there exist an orientable surface Sg, as well as a non-orientable surface Ng, of genus g, and a Morse–Smale diffeomorphism f of this surface such that AP(f) = A. For such a map it implies the existence of points of a minimal period n for each odd n ∈ A. For the orientation-reversing Morse–Smale diffeomorphisms of Sg we identify strong restrictions on AP(f). Our method also provides an estimate of the number of homotopy classes of Morse–Smale diffeomorphisms, which is exponential in *** Codes Primary: 37C25 37E30, 57K20, Secondary: 55M20, 37D15 Copyright © 2024, The Authors. All rights reserved.

关键词： Algebra

Massive Neutron Stars and White Dwarfs as Noncommutative Fuzzy Spheres

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arXiv 2022年

作者： Kalita, Surajit Mukhopadhyay, Banibrata Group Department of Mathematics & Applied Mathematics University of Cape Town Cape Town7700 South Africa Department of Physics Indian Institute of Science Bangalore560012 India

Over the last couple of decades, there are direct and indirect evidences for massive compact objects than their conventional counterparts. A couple of such examples are super-Chandrasekhar white dwarfs and massive neutron stars. The observations of more than a dozen peculiar over-luminous type Ia supernovae predict their origins from super-Chandrasekhar white dwarf progenitors. On the other hand, recent gravitational wave detection and some pulsar observations argue for massive neutron stars, lying in the famous mass-gap between lowest astrophysical black hole and conventional highest neutron star masses. We show that the idea of a squashed fuzzy sphere, which brings in noncommutative geometry, can self-consistently explain either of the massive objects as if they are actually fuzzy or squashed fuzzy spheres. Noncommutative geometry is a branch of quantum gravity. If the above proposal is correct, it will provide observational evidences for noncommutativity. Copyright © 2022, The Authors. All rights reserved.

关键词： Equations of state

Investigating the Constraints on Primordial Features with Future Cosmic Microwave Background and Galaxy Surveys

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arXiv 2022年

作者： Chandra, Debabrata Pal, Supratik Physics and Applied Mathematics Unit Indian Statistical Institute 203 B.T.Road Kolkata700108 India Technology Innovation Hub on Data Science Big Data Analytics and Data Curation Indian Statistical Institute 203 B.T.Road Kolkata700108 India

In this article, we do a thorough investigation of the competency of the forthcoming Cosmic Microwave Background (CMB) and Galaxy surveys in probing the features in the primordial power spectrum. Primordial features are specific model-dependent corrections on top of the standard power-law inflationary power spectrum;the functional form being given by different inflationary scenarios. Signature of any significant departure from the feature-less power spectrum will enable us to decipher the intricacies of the inflationary Universe. Here, we delve into three major yet distinct features, namely, Bump feature, Sharp feature signal, and Resonance feature signal. To analyse the features, we adopt a specific template for each feature model. We estimate the possible constraints on the feature parameters by employing Fisher matrix forecast analysis for the upcoming CMB missions such as CMB-S4, CORE-M5, LiteBIRD, PICO conjointly with DESI, and EUCLID galaxy surveys. To this end, we make use of four distinct observations to forecast on the bounds on the model parameters, namely, CMB, Baryon Acoustic Oscillations (BAO), Galaxy Clustering and Gravitational Weak Lensing or Cosmic Shear and their permissible synergy. For large scale structure (LSS) information, we consider different upper limits of scale for different redshifts for the purpose of circumventing the propagation of the errors stemming from the uncertainties on nonlinear scales into the constraints on the feature parameters. A comparative analysis of all three features has been done to estimate relative capabilities of these upcoming observations in shedding light on this crucial aspect of precision cosmology. Copyright © 2022, The Authors. All rights reserved.

关键词： Power spectrum

Age of Information Optimization Using a Hybrid Preemptive/Non-Preemptive Discipline

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Age of Information Optimization Using a Hybrid Preemptive/No...

IEEE Conference on Vehicular Technology (VTC)

作者： Tamer E. Fahim Sherif I. Rabia Ahmed H. Abd El-Malek Waheed K. Zahra Institute of Basic and Applied Sciences Egypt-Japan University of Science and Technology (E-JUST) Alexandria Egypt Department of Engineering Mathematics and Physics Faculty of Engineering Alexandria University Alexandria Egypt Department of Electronics and Communications Engineering Egypt-Japan University of Science and Technology (E-JUST) Alexandria Egypt Department of Engineering Physics and Mathematics Faculty of Engineering Tanta University Tanta Egypt

ISBN: (数字)9798331517786

ISBN: (纸本)9798331517793

Currently, the pervasive adoption of internet of things technology sheds light on the significance of real-time status update systems. The age of information (AoI) metric has been devised to reflect the strict information timeliness of such systems. Bufferless packet management scheme has demonstrated higher effectiveness in the AoI minimization. However, the existing preemptive (PR) and non-preemptive (NP) service disciplines operate independently of the system state, thereby reducing the system’s adaptability to varying system parameter settings, such as service time distribution and traffic loading condition. Therefore, we propose an elapsed-time-based hybrid PR/NP discipline to govern the service preemptions in a single-source M/Er/1/1 queueing scheme. The preemption is declined when the elapsed service time surpasses a predetermined threshold (controlling parameter). The average AoI is analyzed using the stochastic hybrid system approach. The numerical study demonstrated that the proposed discipline, owing to its threshold parameter, fulfills the optimality of the AoI performance, especially under highly dispersed Erlang service time distributions and higher traffic loading conditions.

关键词： Measurement Vehicular and wireless technologies Loading Stochastic processes Performance gain Information age Minimization Real-time systems Time factors Optimization

An Efficient Three-Factor Authenticated Key Agreement Technique Using FCM Under HC-IoT Architectures

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Computers, Materials & Continua 2022年第7期72卷 1373-1389页

作者： Chandrashekhar Meshram Agbotiname Lucky Imoize Sajjad Shaukat Jamal Parkash Tambare Adel R.Alharbi Iqtadar Hussain Department of Post Graduate Studies and Research in Mathematics Jayawanti Haksar Government Post-Graduation CollegeCollege of Chhindwara UniversityBetul460001M.P.India Department of Electrical and Electronics Engineering Faculty of EngineeringUniversity of LagosAkokaLagos100213Nigeria Department of Electrical Engineering and Information Technology Institute of Digital CommunicationRuhr University44801BochumGermany Department of Mathematics College of ScienceKing Khalid UniversityAbhaSaudi Arabia Water Resources&Applied Mathematics Research Lab Nagpur440027India College of Computing and Information Technology University of TabukTabuk71491Saudi Arabia Mathematics Program Department of MathematicsStatistics and PhysicsCollege of Arts and SciencesQatar University2713DohaQatar

The Human-Centered Internet of Things(HC-IoT)is fast becoming a hotbed of security and privacy *** users can establish a common session key through a trusted server over an open communication channel using a three-party authenticated key *** of the early authenticated key agreement systems relied on pairing,hashing,or modular exponentiation processes that are computationally intensive and *** order to address this problem,this paper offers a new three-party authenticated key agreement technique based on fractional chaotic *** new scheme uses fractional chaotic maps and supports the dynamic sensing of HC-IoT devices in the network architecture without a password *** projected security scheme utilized a hash function,which works well for the resource-limited HC-IoT *** results show that our new technique is resistant to password guessing attacks since it does not use a ***,our approach provides users with comprehensive privacy protection,ensuring that a user forgery attack causes no ***,our new technique offers better security features than the techniques currently available in the literature.

关键词： Three-party authenticated key agreement anonymity fractional chaotic maps Chebyshev polynomial password table human-centered internet of things(HC-IoT)

Two-mode terms in Wigner transport equation elucidate anomalous thermal transport in amorphous silicon

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Physical Review B 2025年第9期111卷 094206-094206页

作者： Jin Yang Xueyan Zhu Alan J. H. McGaughey Yee Sin Ang Wee-Liat Ong ZJU-UIUC Institute College of Energy Engineering Zhejiang University Jiaxing Haining Zhejiang 314400 China China Academy of Engineering Physics Software Center for High Performance Numerical Simulation Beijing 100088 China Institute of Applied Physics and Computational Mathematics Beijing 100088 China Department of Mechanical Engineering Carnegie Mellon University Pittsburgh Pennsylvania 15213 USA Science Mathematics and Technology Singapore University of Technology and Design 487372 Singapore State Key Laboratory of Clean Energy Utilization Zhejiang University Hangzhou Zhejiang 310027 China

Over the past decades, our understanding of thermal transport in amorphous materials has predominantly relied on the inherently harmonic Allen-Feldman theory, which has been found to be insufficient. In this study, the Wigner transport formalism is adopted to explicitly account for anharmonicity. In studying the thermal transport in amorphous silicon, the results highlight that amorphous materials are not generally computationally equivalent to crystals with disordered primitive cells. A method that leverages the properties of the two-mode terms in the Wigner transport formalism is proposed to predict the bulk thermal conductivity of amorphous materials using finite-size models. In doing so, the need for mode classification schemes required in the Allen-Feldman theory is eliminated, and similarities are discovered between the two-mode terms and the carriers commonly used to describe thermal transport in amorphous materials, i.e., propagons, diffusons, and locons. Two competing trends are identified that shed light on the recently discovered anomalous decrease in the high-temperature thermal conductivity in some amorphous materials.

关键词： Heat transfer

Electronic properties of 2D materials and their junctions

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Nano Materials science 2024年第1期6卷 1-23页

作者： Taposhree Dutta Neha Yadav Yongling Wu Gary J.Cheng Xiu Liang Seeram Ramakrishna Aoussaj Sbai Rajeev Gupta Aniruddha Mondal Zheng Hongyu Ashish Yadav Department of Chemistry Indian Institute of Engineering Science and TechnologyShibpurWest Bengal711103India Center for Advanced Laser Manufacturing(CALM) Shandong University of TechnologyZibo255000PR China School of Industrial Engineering Purdue University315 N.Grant St.West LafayetteIN47907United States Birck Nanotechnology Center Purdue University1205 W State St.West LafayetteIN47907United States Advanced Materials Institute Qilu University of TechnologyShandong Academy of SciencesJinan250014PR China Nanoscience and Nanotechnology Initiative National University of Singapore10 Kent Ridge Crescent119260Singapore Faculty of Applied Phsyics and Mathematics Gdansk University of Technology Narutowicza 11/1280233GdanskPoland Department of Physics School of EngineeringUniversity of Petroleum&Energy StudiesDehradun248007UttarakhandIndia Department of Physics National Institute of Technology DurgapurDurgapur713209West BengalIndia

With an extensive range of distinctive features at nano meter-scale thicknesses,two-dimensional(2D)materials drawn the attention of the scientific *** tremendous advancements in exploratory research on 2D materials,knowledge of 2D electrical transport and carrier dynamics still in its ***,here we highlighted the electrical characteristics of 2D materials with electronic band structure,electronic transport,dielectric constant,carriers *** atomic thinness of 2D materials makes substantially scaled field-effect transistors(FETs)with reduced short-channel effects conceivable,even though strong carrier mobility required for high performance,low-voltage device *** also discussed here about factors affecting 2D materials which easily enhanced the activity of those materials for various ***,Those 2D materials used in state-of-the-art electrical and optoelectronic devices because of the extensive nature of their electronic band structure.2D materials offer unprecedented freedom for the design of novel p-n junction device topologies in contrast to conventional bulk *** also,describe the numerous 2D p-n junctions,such as homo junction and hetero junction including mixed dimensional ***,we talked about the problems and potential for the future.

关键词： 2D materials Electrical properties p-n junctions Mixed hereto junctions Homo junctions Electrical transport

An Asymptotic-Preserving Method for the Three-Temperature Radiative Transfer Model

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SSRN

SSRN 2024年

作者： Li, Ruo Li, Weiming Liang, Shengtong Shao, Yuehan Tang, Min Wang, Yanli CAPT LMAM School of Mathematical Sciences Peking University Beijing China Institute of Applied Physics and Computational Mathematics Beijing China School of Mathematical Sciences Peking University Beijing China Institute of Natural Sciences School of Mathematics Shanghai Jiaotong University Shanghai China Beijing Computational Science Research Center Beijing China

We present an asymptotic-preserving (AP) numerical method for solving the three-temperature radiative transfer model, which holds significant importance in inertial confinement fusion. A carefully designed splitting method is developed that can provide a general framework of the extending AP schemes for the gray radiative transport equation to the more complex three-temperature radiative transfer model. The proposed scheme captures two important limiting models: the three-temperature radiation diffusion equation (3TRDE) when opacity approaches infinity and the two-temperature limit when the ion-electron coupling coefficient goes to infinity. We have rigorously demonstrated the AP property and energy conservation characteristics of the proposed scheme and its efficiency has been validated through a series of benchmark tests in the numerical part. © 2024, The Authors. All rights reserved.

关键词： Radiative transfer