International Journal of Theoretical Physics最新文献

Based on the correspondence between operator commutative relations and Poisson brackets, we develop a framework of deformed Hamilton, Lagrange and Euler equations as well as their relations in the noncommutative phase space. We introduce a deformed factor and deformed matrix to measure the departure of the deformed symplectic structure from the canonical symplectic structure. We endow the noncommutative parameters with the Planck length, Planck constant and cosmological constant, which allows us to explore some puzzles from the Planck to cosmological scales. We find that there exist an observer-dependent effective force and moment of force break the translation and rotation symmetries. As a spacetime quantum fluctuation, these formulations and results provide some hints and insights into some unsolved phenomena such as intrinsic spacetime singularities, black hole radiation, dark matter and dark energy as well as anisotropic cosmic radiation background.

This study undertakes a comprehensive analytical and numerical investigation of the nonlinear Kairat model, a significant evolution equation that governs a wide range of physical phenomena, including shallow water waves, plasma physics, and optical fibers. The Kairat model effectively describes the propagation of nonlinear waves in shallow water, capturing the intricate interplay between nonlinearity and dispersion. It exhibits similarities with well-known nonlinear evolution equations such as the Korteweg-de Vries (KdV) and nonlinear Schrödinger (NLS) equations, thereby offering insights into their common underlying dynamics. To achieve the objectives of this research, we employ the modified Khater (MKhat) and unified (UF) methodologies to derive exact solutions for the Kairat model. Furthermore, the trigonometric-quantic-B-spline (TQBS) scheme is utilized as a numerical technique to verify the accuracy of these derived solutions and validate their applicability within the domain of shallow water wave propagation. This investigation yields a collection of innovative and precise analytical solutions, elucidating the complex nonlinear behavior of the Kairat model and its effectiveness in capturing the dynamics of shallow water waves. Moreover, these analytical solutions are corroborated through numerical simulations conducted using the TQBS scheme, ensuring their reliability and practical significance in understanding and predicting shallow water wave phenomena. The significance of this endeavor lies in its contribution to a deeper understanding of the dynamics of the Kairat model and its potential applications in fields such as coastal engineering, oceanography, and related disciplines. The integration of analytical and numerical techniques offers new perspectives and methodologies for exploring nonlinear evolution equations, potentially benefiting researchers in applied mathematics, physics, and engineering. In summary, this comprehensive analytical and numerical investigation provides novel insights, precise solutions, and a robust foundation for further exploration of the physical implications and applications of the Kairat model in the context of shallow water wave propagation.

The explicit expression for the propagator of the Dirac delta potential in three dimensional hyperbolic spaces is derived using the integral transform of the Krein’s type of the resolvent formula, obtained after the renormalization procedure.

This work is devoted to study the structural and reactional properties of the prototypical example of the core–halo ((^{9})Li–(^{11})Li) nuclei. The halo nucleus (^{11})Li consists of a central core of (^{9})Li surrounded by 2n–halo with very low separation energy (varepsilon _{2n})= 378±5 KeV, reflecting the huge calculated root mean square radius value 4.11 fm. The elastic scattering potential at low and intermediate incident energies was a puzzle for decades of research on nuclear reactions. Single– and double–folding potentials describing the elastic scattering of (^{11})Li from the proton and (^{12})C, based on different effective interactions were constructed. Systematic comparison between the considered methods in terms of the renormalization coefficients is done. Based on the considered methods, the obtained potentials doesn’t need any renormalization in case of using real folding potential together with phenomenological imaginary potential and merely need renormalization almost approach unity in case of using complex folding potential to fit the total reaction cross sections and angular distributions along the measured data. Furthermore, correlations between real volume integrals and nucleon incident energies for the neutron drip–line (^{11})Li nucleus were proven along the whole scale of energies.

The new local group LB1 introduced previously will be studied and reviewed in detail, depicting its unique nature that makes it a new group in fundamental physics. It will be made clear that even though most of its elements are Lorentz transformations, one unique discrete transformation not present in the Lorentz groups, is making this group into a new group because it is a reflection. In addition there will be four particular transformations onto the local light cone. It is these discrete transformations that allow for an isomorphism between the group U(1) and LB1. This result will have profound resonations in all of particle physics, general relativity, relativistic astrophysics, Riemannian geometry and group theory. These new group will be associated to a whole set of new experiments put forward.

We study the electron–phonon and Rashba spin–orbit coupling effects on thermodynamic properties of a monolayer graphene under magnetic field. We propose a diagonalization procedure to solve the Fröhlich-type Hamiltonian based on the Lee–Low–Pines theory. The study reveals that, the cyclotron frequency, Debye cut-off wavenumber (DCOW) and Rashba spin–orbit coupling (RSOC) modulate the thermodynamic properties through Tsallis formalism for different substrates. It is also found that RSOC induce a gap formation while dropping the disorder thus rising up the potential application.

In the QBist approach to quantum mechanics, a measurement is an action an agent takes on the world external to herself. A measurement device is an extension of the agent and both measurement outcomes and their probabilities are personal to the agent. According to QBism, nothing in the quantum formalism implies that the quantum state assignments of two agents or their respective measurement outcomes need to be mutually consistent. Recently, Khrennikov has claimed that QBism’s personalist theory of quantum measurement is invalidated by Ozawa’s so-called intersubjectivity theorem. Here, following Stacey, we refute Khrennikov’s claim by showing that it is not Ozawa’s mathematical theorem but an additional assumption made by Khrennikov that QBism is incompatible with. We then address the question of intersubjective agreement in QBism more generally. Even though there is never a necessity for two agents to agree on their respective measurement outcomes, a QBist agent can strive to create conditions under which she would expect another agent’s reported measurement outcome to agree with hers. It turns out that the assumptions of Ozawa’s theorem provide an example for just such a condition.

Our research on fractional-order nonlinear Schrödinger equations (FONSEs) reveals several new findings, which may contribute to our comprehension of wave dynamics and hold practical importance for the field of ocean engineering. We have employed an innovative approach to derive double periodic Weierstrass elliptic function solutions for FONSEs, thereby offering exact solutions for these equations. Additionally, we have observed that fractional derivatives significantly impact the dynamics of solitary waves, potentially holding significance for the design of ocean structures. Our research reveals the previously unknown phenomenon of oblique wave variations, which can impact the reliability and lifespan of offshore structures. Our findings highlight the significance of taking into account various fractional derivatives in future studies. Using the planar dynamical system technique, we gain a deeper understanding of the behavior of FONSEs, revealing critical thresholds and regions of chaotic behavior. Linear stability analysis provides a strong framework for studying the modulation instability of dynamical systems, shedding light on the conditions and mechanisms of modulated behavior. Applying this analysis to the FONSEs offers insights into the critical parameters, growth rates, and formation of modulated patterns, with potential implications for innovative research in ocean engineering.

The exact solutions and qualitative analysis of the stochastic governing model for embedded solitons with (chi ^{(2)}) and (chi ^{(3)}) nonlinear susceptibilities are investigated in this study. The model introduces a stochastic term-white noise for the first time, bringing the model closer to reality. The trial equation method is used for mathematical analysis and the complete discriminant system for polynomial method is used for qualitative analysis. Using the bifurcation theory and the complete discriminant system for polynomial method, the existence of the soliton and periodic solutions is confirmed and the exact travelling wave solutions are generated to validate our findings. Furthermore, we explore the various sorts of exact solutions by illustrating the associated phase diagrams and providing two-dimensional diagrams to demonstrate the model’s dynamical behavior. The plethora of exact solutions shows that the effect of white noise exists only in the phase component of the solitons, providing insight into the optical solitons of stochastic nonlinear models.

Quantum Fisher information (QFI) is frequently utilized to investigate quantum criticality in various spin-chain models. However, little attention has been given to the quantum Fisher information matrix (QFIM) in this context. This study examines criticality and the strategy for the simultaneous estimation of multiple parameters using the QFIM in an Ising-XXZ diamond structure at finite temperatures. Our findings demonstrate that by analyzing the finite-temperature scaling behavior, the variances derived from the QFIM can accurately estimate the critical point in this model. Additionally, we observe that the behavior of variances is contingent upon both the system structure and the parameters used. Moreover, whether the multi-parameter simultaneous estimation strategy is advantageous over individual parameter estimation depends on the system structure, temperature, and the parameters applied.