Theoretical Physics Research Articles

Time Evolution in Quantum Mechanics with a Minimal Time Scale

The existence of a minimum measurable length scale was suggested by various theories of quantum gravity, string theory and black hole physics. Motivated by this, we examine a quantum theory exhibiting a minimum measurable time scale. We use the Page–Wootters formalism to describe time evolution of a quantum system with the modified commutation relations between the time and frequency operator. Such modification leads to a minimal uncertainty in the measurement of time. This causes breaking of the time-translation symmetry and results in a modified version of the Schrödinger equation. A minimal time scale also allows us to introduce a discrete Schrödinger equation describing time evolution on a lattice. We show that both descriptions of time evolution are equivalent. We demonstrate the developed theory on a couple simple quantum systems.

On the kinetic physical and mathematical metal creep theory controlled by thermally activated dislocation sliding

The rationale for the prospects of using the physical and mathematical theory of metal creep in creep computations is carried out by a comparative analysis of the classical phenomenological and physical and mathematical metal creep theories. On the example of the description by both theories specific results of non-stationary creep experiments and analysis of the theories equations it is shown that implementing the physical kinetic equation for the actual structural parameter of the material, namely the scalar density of immobile dislocations, makes the physical and mathematical theory universal for solving non-stationary metal creep problems with multiaxial loading, when change, including abruptly, temperature, forces and loading rates.

Speed controller design for turboshaft engine using a high-fidelity AeroThermal model

Abstract One of the main objectives of this research is to construct a high-fidelity aerothermal model for controlling the turboshaft engine power turbine rotational speed. Firstly, a high-fidelity aerothermal model of General Electric T700 is formed. The turboshaft engine aerothermal model is simulated and compared to engine design point data on MATLAB/Simulink environment. Thermodynamic equations and some algebraic equations are used. In predicting compressor mass flow rate, the adaptive neuro-fuzzy inference system method is preferred. A propeller model is also added to the turbo shaft engine aerothermal model and to keep the power turbine rotational speed at a constant value, a Proportional Integral Derivative controller is designed and applied. Open-loop and closed-loop simulations are conducted and successful outcomes are achieved. Results indicate that the differences between simulation and actual engine data are within acceptable limits. The suggested model can be readily updated and expanded to control additional parameters of the engine. PACS 2010 Classification: Control theory in mathematical physics, 02.30. Yy, Computer modeling and simulation, 07.05.Tp, 05.70.Ce Thermodynamic functions and equations of state.

Theoretical and Practical Exploration of Basketball Education

The importance of basketball education in today's school physical education is increasingly evident. With the development of physical education theory, basketball not only serves as a sport, but also as an educational tool, profoundly influencing students' physical fitness, psychological development, and social adaptability. This article comprehensively elaborates on the role of basketball education in cultivating the comprehensive quality of young people through theoretical analysis and in-depth exploration of practical cases. It analyzes its practical application and challenges in the current educational environment and proposes suggestions for optimizing basketball education.

A rock physics modelling approach for time‐lapse monitoring and characterization of fluid–rock interactions in hydrocarbon reservoirs

AbstractOne of the research gaps is to understand the development of seismic characteristics of gas‐saturated rock along with the change in rock properties because of chemical reactions. We suggest a method to explain the change in elastic properties brought on by CO2 injection in a rock by capturing the physico‐chemical interactions observed in the laboratory in a theory of rock physics. To explain the laboratory‐measured physical characteristics and velocity of a dynamic rock–fluid system, we include a time‐dependent component in the existing cemented‐sand model. We demonstrate theoretically the rate of change of elastic moduli of the dry frame by incorporating the measured rate of change of cement due to chemical dissolution. We adapt the theory such that it can be applied to the field data and calibrate the theory using water‐saturated well log data from the Ankleshwar field, an established oil field in the Cambay basin, western India. Theoretical time‐lapse logs of velocity and density are then produced using the theory over a range of CO2 saturations, assuming cementing material in grain contacts and geochemical interactions comparable to those observed in the laboratory rock. Then, using theoretical logs, corresponding time‐lapse synthetic seismic data are produced for different saturation. These data clearly demonstrate that, for a uniform model, velocity decreases by up to 18% as CO2 saturation increases from 0% to 20% (ignoring the chemical effect), and that, for a specific saturation, say 20%, chemical effects result in a 17% decrease in velocity from the present to the end of 60 years. However, for the patchy model, velocity decreases maximum by 14% and 16% due to varying saturation and chemical reaction. Moreover, for a particular saturation of CO2, say 20%, velocity differs by 16% for different types of models. This research contributes to making strategy for CO2‐sequestration in a designated field.

Aristotle and the Stoics on the Notion of ἐνέργεια

Abstract The Stoic theory of movement has never been the object of a deep investigation despite the considerable number of sources in Neoplatonist commentators. This paper explores for the first time the Stoic notion of ἐνέργεια, which plays a fundamental role in the Stoic conception of movement and generally in the characterization of interaction between bodies. I will show that the Stoics identified movement and activity, so that everything that is active is necessarily moved. This implies that the Stoics merely characterized ἐνέργεια in a dynamic or kinetic sense, namely by connecting it with movement. In order to prove the coherence of this philosophical position to the Stoic doctrine, I will display the compatibility of Neoplatonists’ reports with other sources. Accordingly, I will claim that the Stoics conceived this peculiar sense of ἐνέργεια in reaction to Aristotle, who clearly distinguished between ἐνέργεια and κίνησις in his physical theory.

Solving superconducting quantum circuits in Dirac's constraint analysis framework**The paper is dedicated to the memory of Professor Roman Jackiw, who apart from working in diverse branches of theoretical physics, has contributed significantly in quantization of constraint systems.

Abstract In this work we exploit Dirac's Constraint Analysis (DCA) in Hamiltonian formalism to study different types of Superconducting Quantum Circuits (SQC) in a unified way. The Lagrangian of a SQC reveals the constraints, that are classified in a Hamiltonian framework, such that redundant variables can be removed to isolate the canonical degrees of freedom for subsequent quantization of the Dirac Brackets via a generalized Correspondence Principle. This purely algebraic approach makes the application of concepts such as graph theory, null vector, loop charge, etc that are in vogue, (each for a specific type of circuit), completely redundant. The universal validity of DCA scheme in SQC, proposed by us, is demonstrated by correctly re-deriving existing results for different SQCs, obtained previously exploiting different formalisms each applicable for a specific SQC. Furthermore, we have also analysed and predicted new results for a generic form of SQC - it will be interesting to see its validation in an explicit circuit implementation.

New Estimates of the Potential Schrödinger Equation

The Schrödinger equation, a fundamental construct in quantum mechanics, plays a pivotal role in understanding the properties and behaviors of quantum systems across various scientific fields, including but not limited to physics, economics, and geophysics. This research paper delves into the exploration of novel invariants associated with the Schrödinger equation, uncovering previously unrecognized symmetries and properties that open new pathways for theoretical and applied scientific exploration. The investigation reveals that the energy of bound states remains invariant under transformations of the coordinate system, highlighting a universal symmetry embedded within the equation. This discovery, coupled with an analysis of the variation in scattering amplitudes’ phase with different coordinate systems, not only enriches the theoretical framework of quantum mechanics but also has significant practical implications across various domains such as fluid dynamics, material science, and medical imaging. Furthermore, by applying the principles of the Poincaré-Riemann-Hilbert boundary-value problem, the study offers a novel approach to estimate potentials within the Schrödinger equation, advancing the three-dimensional inverse problem of quantum scattering theory. This methodological innovation allows for a more profound understanding of the unitary scattering operator, facilitating enhanced modeling of complex systems and phenomena. The implications of these findings extend beyond theoretical physics, offering transformative insights and applications in areas ranging from fluid dynamics, where it aids in refining models for the Navier-Stokes equations, to seismic exploration, tomography, and ultrasound imaging, where it enhances phase selection and interpretation of measurement results. In essence, this research not only contributes to a deeper understanding of the Schrödinger equation’s fundamental properties but also paves the way for interdisciplinary advancements, demonstrating the profound impact of theoretical discoveries on practical applications in diverse scientific and technological domains.

Particle Identification in High Energy Collisions at RHIC

This article provides a technical introduction to the study of collider physics by focusing on the concept of particle identification (PID). Through a general overview of the Relativistic Heavy Ion Collider (RHIC) and the Pioneering High Energy Nuclear Interaction Experiment (PHENIX), the author discusses the role of Vanderbilt University researchers in collaborative work at the Brookhaven National Laboratory. After explaining the concept of event reconstruction and centrality with graphical images of experimental results, the author outlines the time-of-flight method of particle identification in high energy physics. A final presentation of the design concept for the Multi-Gap Resistive Plate Chamber (MRPC) integrates the more traditional foundations of theoretical physics with the next generation of physics experimentation in the field.

Development of Virtual Reality Hydroelectric (VIRRIC) for teaching students about renewable energy

Understanding abstract physics theories, such as energy, can be challenging for students. Teachers also face the difficulty of meeting learning objectives within limited classroom time. The purpose of this research is to develop physics learning media to teach high school students about renewable energy. The learning media is presented as virtual reality, focusing on the energy conversion process in hydroelectric power plants. The goal is for students to apply their understanding of energy conversion concepts in hydroelectric power plants as one type of renewable energy source. The research process follows the ADDIE model, focusing on the analysis, design, and development stages. Data is collected through validation sheets completed by media experts, which provide valuable suggestions for revisions. The data was analyzed using descriptive statistical methods. It is known that at this level of education, the cognitive level required for understanding renewable energy material is C4 according to the revised Bloom's taxonomy. At the design stage, storyboards are used to frame the media development process, comprising a problem orientation scene and an exploration scene. After development, the VIRRIC media was validated based on visual aspects, interest, usefulness, accuracy, legitimacy, and structure. The final media expert validation score for the VIRRIC media is 0.87, categorized as highly valid. The lowest score was in the visual aspect, which was 0.77. This was due to some text information in the media being difficult to read. The text is observable when not using a gyro device, but becomes difficult to read when observed using a gyro device. Based on these results, the VIRRIC media is deemed suitable for testing in learning after making improvements.

Wilson Lines in the Abelian Lattice Higgs Model

Lattice gauge theories are lattice approximations of the Yang–Mills theory in physics. The abelian lattice Higgs model is one of the simplest examples of a lattice gauge theory interacting with an external field. In a previous paper (Forsström et al. in Math Phys 4(2):257–329, 2023), we calculated the leading order term of the expected value of Wilson loop observables in the low-temperature regime of the abelian lattice Higgs model on Z4,\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\mathbb {Z}}^4,$$\\end{document} with structure group G=Zn\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$G = {\\mathbb {Z}}_n$$\\end{document} for some n≥2.\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$n \\ge 2.$$\\end{document} In the absence of a Higgs field, these are important observables since they exhibit a phase transition which can be interpreted as distinguishing between regions with and without quark confinement. However, in the presence of a Higgs field, this is no longer the case, and a more relevant family of observables are so-called open Wilson lines. In this paper, we extend and refine the ideas introduced in Forsström et al. (Math Phys 4(2):257–329, 2023) to calculate the leading order term of the expected value of the more general Wilson line observables. Using our main result, we then calculate the leading order term of several natural ratios of expected values and confirm the behavior predicted by physicists.

Lebt of the Heavy Ion Linear Accelerator

At the NRC “Kurchatov Institute” (Kurchatov Complex for Theoretical and Experimental Physics), the pulsed linear resonant heavy ion accelerator is being developed. The Low Energy Beam Transport (LEBT) channel transports the beam from a laser-plasma source of multi-charged ions with an A/Z ratio from 4 to 8 (up to Bi27+) to the RFQ. This paper shares the results of the beam dynamics simulation of the LEBT, which ensures the separation of the working fraction of the ion beam and its matching with the RFQ.

Una breve storia dei concetti di matematica e fisica

It is shown that there is no clear boundary between mathematics and physics, and a brief history of the concepts of mathematics and physics is outlined. Not only the scientists of antiquity, but also Copernicus and Galileo referred to all the exact sciences by the term mathematics and used the word physics for the philosophy of nature. In Newton’s time, the unity of the exact sciences broke down, and from the combination of part of mathematics with the philosophy of nature modern physics was born. The article then describes how mathematical physics, which began as part of physics, was pushed back into mathematics by the birth of theoretical physics. Finally, the epistemological status of the current branches of the exact sciences is discussed.

Weak cosmic censorship and weak gravity conjectures in CFT thermodynamics

In this paper, we explore the intriguing interplay between fundamental theoretical physics concepts within the context of charged black holes. Specifically, we focus on the consistency of the weak gravity conjecture (WGC) and weak cosmic censorship conjecture (WCCC) in the thermodynamics of conformal field theory (CFT), and restricted phase space thermodynamics (RPST) for AdS Reissner-Nordström black holes with a perfect fluid dark matter (RN-PFDM). The WGC ensures that gravity remains the weakest force in the system. Meanwhile, the WCCC addresses the cosmic censorship problem by preventing the violation of fundamental physical laws near the black hole singularity. First, we analyze the RN black hole's free energy in both spaces, revealing a distinctive swallowtail pattern indicative of a first-order phase transition when certain free parameter conditions are met. We explore the WGC across different phase spaces, emphasizing the need for certain conditions in extended phase space thermodynamics (EPST), RPST, and CFT. We demonstrate that PFDM parameter γ and the radius of AdS l have a vital role in proving the satisfaction of the WGC. Also, these values have a linear relation with the range compatibility of WGC. The range of compatibility for WGC in RPST and EPST is the same while for CFT, this range is larger than EPST, and RPST. It means somehow the WGC and CFT are more consistent. The WCCC was examined at the critical juncture, confirming its validity in critical points. We conclude that the WGC is supported at the critical point of black holes, and the WCCC is also maintained, demonstrating the robustness of these conjectures within the critical ranges of black hole parameters.

Flexible Cooling Strategy for Hot-Rolled Steel Based on Physical Theories Coupled with Machine Learning

Flexible Cooling Strategy for Hot-Rolled Steel Based on Physical Theories Coupled with Machine Learning

On the Possibility of Scientific Philosophy for Satisfactory Solution of the Problem of Interrelation of Classical and Quantum Physics

As we know the main results of quantum physics in 1900 Planck began to obtain mainly because of the need to describe the experimental data. Therefore, it further became necessary to obtain theoretical justifications for these results. This means to obtain proofs of these results on the basis of the basic equations of theoretical physics, i.e. equations that are obtained on the way where the right choice of results is made performing the role of the basis of the theory of thought. As is known, these problems began to be solved, taking as a basis the possibilities of the following new ideas of Bohr. That quantum physics should be considered as a generalization of classical physics. But as we know, this path led to the results of matrix mechanics. Results for which such contradiction as non-commutativity of multiplication is inherent. In this paper for obtaining proofs for the results of Planck's quantum physics the fundamental ideas in the field of scientific philosophy were taken as a basis. That is philosophy where from the very beginning for the basis of the theory of thinking the possibilities of equations of algebra and arithmetic are accepted

Beam Dynamics in the Heavy Ion Injector LU2 for the Synchrotron Research Complex (SRC)

The project of the complex for studying ionizing radiation exposure from outer space based on the synchrotron accelerator of protons and various types of ions up to 209Bi is being developed at the Russian Federal Nuclear Center - All-Russian Research Institute ofExperimental Physics (FSUE RFNC - VNIIEF). The accelerator includes two injection complexes (one of which is the source of protons and light ions, the second - heavy ions), the booster accelerator and the main synchrotron. The pulsed type heavy ions linac is being developed at the NRC “Kurchatov Institute” - KCTEF (Kurchatov Complex for Theoretical and Experimental Physics). The ions with mass-to-charge ratio 4÷8 with current of 10 mA will be accelerated up to 4 MeV/u. The linac is proposed, including the RFQ and two DTL sections operating at multiple frequencies. Each DTL section is modular and consists of individually phased H-type resonators (IH-DTLs). Quadrupole lenses located between the resonators for the beam focusing. This DTL structure ensures the accelerator compactness and allows section-by-section configuration and sequential commissioning. 6D beam matching between all sections of the linac is carried out. The results ofbeam dynamics simulation in linear accelerator are presented.

Recent Progress of Imaging Chemical Bonds by Scanning Probe Microscopy: A Review.

In the past decades, the invention of scanning probe microscopy (SPM) as the versatile surface-based characterization of organic molecules has triggered significant interest throughout multidisciplinary fields. In particular, the bond-resolved imaging acquired by SPM techniques has extended its fundamental function of not only unraveling the chemical structure but also allowing us to resolve the structure-property relationship. Here, we present a systematical review on the history of chemical bonds imaged by means of noncontact atomic force microscopy (nc-AFM) and bond-resolved scanning tunneling microscopy (BR-STM) techniques. We first summarize the advancement of real-space imaging of covalent bonds and the investigation of intermolecular noncovalent bonds. Beyond the bond imaging, we also highlight the applications of the bond-resolved SPM techniques such as on-surface synthesis, the determination of the reaction pathway, the identification of molecular configurations and unknown products, and the generation of artificial molecules created via tip manipulation. Lastly, we discuss the current status of SPM techniques and highlight several key technical challenges that must be solved in the coming years. In comparison to the existing reviews, this work invokes researchers from surface science, chemistry, condensed matter physics, and theoretical physics to uncover the bond-resolved SPM technique as an emerging tool in exploiting the molecule/surface system and their future applications.

A physically inspired approach to coarse-graining transcriptomes reveals the dynamics of aging.

Single-cell RNA sequencing has enabled the study of aging at a molecular scale. While substantial progress has been made in measuring age-related gene expression, the underlying patterns and mechanisms of aging transcriptomes remain poorly understood. To address this gap, we propose a physics-inspired, data-analysis approach to extract additional insights from single-cell RNA sequencing data. By considering the genome as a many-body interacting system, we leverage central idea of the Renormalization Group to construct an approach to hierarchically describe aging across a spectrum of scales for the gene expresion. This framework provides a quantitative language to study the multiscale patterns of aging transcriptomes. Overall, our study demonstrates the value of leveraging theoretical physics concepts like the Renormalization Group to gain new biological insights from complex high-dimensional single-cell data.

Optimizing Wide Band Gap Cu(In,Ga)Se2 Solar Cell Performance: Investigating the Impact of "Cliff" and "Spike" Heterostructures.

In recent years, the efficiency of high-efficiency Cu(In,Ga)Se2 (CIGS) solar cells has been significantly improved, particularly for narrow-gap types. One of the key reasons for the enhancement of narrow-gap device performance is the formation of the "Spike" structure at the CdS/CIGS heterojunction interface. Wide-gap CIGS solar cells excel in modular production but lag behind in efficiency compared to narrow-gap cells. Some studies suggest that the "Cliff" structure at the heterojunction of wide-gap CIGS solar cells may be one of the factors contributing to this decreased efficiency. This paper utilizes the SCAPS software, grounded in the theories of semiconductor physics and photovoltaic effects, to conduct an in-depth analysis of the impact of "Cliff" and "Spike" heterojunction structures on the performance of wide band gap CIGS solar cells through numerical simulation methods. The aim is to verify whether the "Spike" structure is also advantageous for enhancing wide-gap CIGS device performance. The simulation results show that the "Spike" structure is beneficial for reducing interfacial recombination, thereby enhancing the VOC of wide-gap cells. However, an electronic transport barrier may form at the heterojunction interface, resulting in a decrease in JSC and FF, which subsequently reduces device efficiency. The optimal heterojunction structure should exhibit a reduced "Cliff" degree, which can facilitate the reduction of interfacial recombination while simultaneously preventing the formation of an electronic barrier, ultimately enhancing both VOC and device performance.