International Journal of Theoretical Physics最新文献

{"title":"Bohmian Trajectories Within Hilbert Space Based Quantum Mechanics. Solution of the Measurement Problem","authors":"Tulsi Dass","doi":"10.1007/s10773-026-06307-3","DOIUrl":"10.1007/s10773-026-06307-3","url":null,"abstract":"<div><p>de Broglie-Bohm theory (dBBT), treating quantum particles as point objects moving along well defined (Bohmian) trajectories, offers an appealing solution of the measurement problem in quantum mechanics; it has, however, problems relating to spin, relativity and lack of proper integration with the Hilbert space based framework. In this work, we present a consistent Hilbert space based formalism which has the traditional state-observable framework integrated with the desirable features of dBBT. We adopt ensemble interpretation for the Schr<span>(ddot{o})</span>dinger wave function <span>(psi )</span>. Using a fixed time wave function <span>(psi _{0})</span> to make the system configuration space <span>( M (= mathbb {R}^n))</span> a probability space <span>(mathcal {M}_{0} = (mathbb {R}^n, |psi _{0}|^2 dx))</span>, we introduce a stochastic process <span>(xi (t))</span> such that its expectation value in <span>(mathcal {M}_{0})</span> equals that of the Heisenberg position operator <span>(X_{H}(t))</span> in the Heisenberg state <span>(|psi _{H}rangle )</span> corresponding to <span>(psi _{0})</span>. This condition leads to the de Broglie-Bohm guidance equation for the sample paths of the process <span>(xi (t))</span> which are, therefore, Bohmian trajectories supposedly representing time-evolutions of individual members of the <span>(psi _{0})</span>-ensemble. Stochastic processes and Bohmian trajectories corresponding to observables with discrete eigenvalues (in particular spin) are treated by extending the configuration space to the spectral space of the commutative algebra obtained by adding appropriate discrete observables to the position observables. Pauli’s equation (the Schr<span>(ddot{o})</span>dinger equation for a nonrelativistic charged spin half particle) is treated as an example. A straightforward <i>derivation</i> of von Neumann’s projection rule employing the Schr<span>(ddot{o})</span>dinger - Bohm evolution of individual systems along their Bohmian trajectories is given. Some comments on the potential application of the formalism developed here to quantum mechanics of the universe are included.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147607245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

{"title":"Dynamics of Non-local Features in One-Axis Twisting States under Dephasing Noise with Gaussian-Modulated Drive","authors":"Muhammad Noman,&nbsp;Ramita Sarkar,&nbsp;Khushnood Shah,&nbsp;Aqsa Mushtaq,&nbsp;S. M. Zangi","doi":"10.1007/s10773-026-06320-6","DOIUrl":"10.1007/s10773-026-06320-6","url":null,"abstract":"<div><p>We investigate the dynamics of nonlocal quantum correlations in one-axis-twisted atom–cavity states under dephasing noise and a Gaussian-modulated coherent drive. Using the Lindblad master-equation approach, we analyze the evolution of concurrence and local quantum uncertainty, where the latter captures discord-type quantum correlations beyond entanglement. By varying the pulse width, drive amplitude and phase, twisting strength, Kerr nonlinearity, atom–cavity coupling, longitudinal interaction, and dissipation rates, we identify parameter regimes that enhance the robustness of quantum correlations. The results show that broader Gaussian pulses significantly improve the preservation of both entanglement and discord-type correlations, while suitable nonlinear and coupling strengths promote partial revivals and stronger resistance to decoherence. These findings provide useful insight into the control of nonlocal quantum features in driven open systems and may be relevant for cavity- and circuit-QED implementations.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147607172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

{"title":"Efficient Internal-State Separation of Chiral Molecules via PT-Symmetric System Regulation","authors":"H. X. He,&nbsp;H. D. Liu","doi":"10.1007/s10773-026-06325-1","DOIUrl":"10.1007/s10773-026-06325-1","url":null,"abstract":"<div><p>This study proposes an efficient method for the internal-state separation of enantiomers in an open system. Under large detuning conditions, by introducing balanced gain and dissipation into the cyclic three-level systems of chiral molecules, we reduce the systems to effective parity-time (PT)-symmetric two-level systems. Both enantiomers are initially prepared in the ground state. When parameters confine them within the PT-symmetric phase, their ground- and excited-state populations exhibit periodic oscillations with distinct periods. Through parameter modulation, left-handed enantiomers stay in the PT-symmetric phase with populations oscillating periodically, while right-handed ones enter the PT-broken phase with populations growing exponentially. Efficient internal-state separation can be achieved in both scenarios by optimizing parameters such that distinct enantiomers occupy different energy levels at a specific evolution time.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147607009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

{"title":"Cosmology in the Perspective of Metric-affine (F(R, mathcal {T})) Gravity","authors":"Shaily,&nbsp;Sonal Aggarwal,&nbsp;Niraj Kumar,&nbsp;Tuan Q. Do,&nbsp;J. K. Singh","doi":"10.1007/s10773-026-06315-3","DOIUrl":"10.1007/s10773-026-06315-3","url":null,"abstract":"<div><p>In this work, we present a fascinating relation to probe the late-time cosmology directed by recent developments in classical cosmology under the Myrzakulov Gravity. We investigate a cosmological model within the framework of metric-affine <span>(F(R, mathcal {T}))</span> gravity, where <i>R</i> is the Ricci curvature scalar and <span>( mathcal {T} )</span> is the torsion scalar associated with a non-special connection. We take the linear function of <span>( F(R, mathcal {T}) )</span>, and find the solution of the modified field equations (FEs) for Myrzakulov Gravity-I, applying the model’s independent approach. Moreover, we employ a Markov chain Monte Carlo (MCMC) simulation to determine the model parameters within the confidence regions <span>( 1sigma )</span> and <span>( 2sigma )</span> using the latest observational datasets. The density parameters for dark energy (DE) and dark matter (SCDM), the deceleration parameter (<i>q</i>), and the EoS parameter (<span>( omega )</span>) exhibit how the Universe evolves our model within Myrzakulov Gravity, furnishing an appropriate scenario of the late-time cosmology. Finally, we find that our model represents a quintessence dark energy model and approaches the <span>( Lambda )</span>CDM at later times.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147607275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

{"title":"Probing a Regular Bardeen-de Sitter Black Hole with String Clouds and Quintessence via Scalar Perturbations and Geodesics","authors":"A. Farhat,&nbsp;Z. Yousaf","doi":"10.1007/s10773-026-06310-8","DOIUrl":"10.1007/s10773-026-06310-8","url":null,"abstract":"<div><p>An in-depth investigation of a regular Bardeen-de Sitter black hole encircled by quintessence and a cloud of strings is presented in this article. We begin by comparing our metric to the classical Schwarzschild geometry and analyzing the effects of various parameter choices on the spacetime geometry. In particular, we investigate situations using both positive (1/2) and negative <span>((-1/2))</span> <span>(Lambda )</span>. Next, we investigate particle geodesic motion, looking at how the modified spacetime of the particular black hole affects massive and massless entities nearby. Next, we examine the forces acting on the photons for different values and show what distinct combinations of the chosen parameters affect the dynamics of the Bardeen black hole. We also analyze the energy associated with circular orbits and how it changes as the parameters change. We examine perturbative dynamics of a massless scalar field, concentrating on the perturbation potential, to advance our investigation. The entire work enables us to learn more about the stability and dynamical behavior of spacetime with minor perturbations. Overall, our work provides a comprehensive understanding of the effects of regular de-Sitter black holes with additional fields, such as quintessence and clouds of strings, on particle motion, forces, and scalar field evolution in curved spacetime.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147607276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

{"title":"Finite Classical and Quantum Effect Algebras","authors":"Stan Gudder","doi":"10.1007/s10773-026-06312-6","DOIUrl":"10.1007/s10773-026-06312-6","url":null,"abstract":"<div><p>In this article, we only consider finite effect algebras. We define the concepts of classical and quantum effect algebras and show that an effect algebra <i>E</i> is classical if and only if there exists an observable that measures every effect of <i>E</i>. We next consider matrix representations of effect algebras and prove an effect algebra is classical if and only if its matrix representation has precisely one row. We then discuss sum table for effect algebras. Although these are not as concise as matrix representations, they give more immediate information about effect sums which are the basic operations of an effect algebra. We subsequently study states on effect algebras and prove that classical effect algebras are quantum effect algebras. Finally, we consider composites of effect algebras. This allows us to study interacting systems described by effect algebras. We show that two effect algebras are classical if and only if their composite is classical.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147561585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

{"title":"Beyond Quantum Individuals: Quasi-Sets and the Philosophy of Quantum Logics","authors":"J. A. F. Cuesta,&nbsp;J. P. Jorge","doi":"10.1007/s10773-026-06318-0","DOIUrl":"10.1007/s10773-026-06318-0","url":null,"abstract":"<div><p>Standard quantum logics are typically defined over the orthomodular lattice associated with Hilbert space, yet there is no consensus on how this structure should be interpreted logically or ontologically. This paper offers a unified perspective on these issues by combining an epistemological three-layer model for scientific theories with quantum set theory. We argue that quasi-set theory is best understood not as an alternative semantics for quantum logics, but as an ontological framework operating at a different epistemological level: the ontological one. From this standpoint, the distinctive non-classical features of quantum logic are explained by representational assumptions about identity and individuality, rather than by positing any direct revisions of the logical principles themselves.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10773-026-06318-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147561584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advance Periodic Waves and Closed-Form Invariant Solutions for ((2 + 1))-Dimensional Hyperbolic Nonlinear Schrödinger (HNLS) Equation via Two Efficient Mathematical Approaches","authors":"Amit Kumar,&nbsp;Dharmendra Kumar,&nbsp;Ashwani Saharan","doi":"10.1007/s10773-026-06313-5","DOIUrl":"10.1007/s10773-026-06313-5","url":null,"abstract":"<div><p>This paper mainly analyzes different analytical solutions of <span>((2 + 1))</span>-dimensional hyperbolic nonlinear Schrodinger equation (HNLS). The problem is employed to model wave propagation, when the dispersion relation’s Hessian is neither strictly positive nor negative. This equation provides a foundational framework for modeling a wide range of physical phenomena, including the propagation of electromagnetic fields, the dynamics of optical soliton transmission, and the evolution of water wave surfaces. In this study, we derive novel and distinct exact solutions of the equation using two effective numerical techniques: the Lie symmetry analysis, and the <span>(phi ^6)</span>-expansion method that have not been reported earlier. Firstly, we apply the <span>(phi ^6)</span>-expansion technique, which presents the exact soliton solutions and also their dynamical structures. The Lie group method reveals nine Lie algebra generators (isomorphism groups), which are employed to investigate the underlying symmetries of the equation. Initially, we determine the associated infinitesimal transformations by applying the one-parameter Lie symmetry approach. Subsequently, we solve the infinitesimal generators to reduce the governing partial differential equation (PDE) into forms with fewer independent variables. These reduced PDEs yield invariant solutions to the governing equation. The resulting exact solutions exhibit diverse dynamic behaviors, including periodic wave solitons, interaction of periodic waves, solitary waves, multisoliton formations, as well as traveling and standing wave profiles. To illustrate these solutions, we present a variety of graphical representations, including two-dimensional (2D), three-dimensional (3D), and contour plots. Furthermore, the exact analytical solutions are computed and verified using symbolic computational tools such as Mathematica. A broad spectrum of novel analytical solutions with distinct dynamical characteristics is analyzed through this approach.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147561550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

{"title":"Matter Spin Networks and Gauge Invariance at Planck Scales","authors":"Mikhail Altaisky","doi":"10.1007/s10773-026-06304-6","DOIUrl":"10.1007/s10773-026-06304-6","url":null,"abstract":"<div><p>Local gauge invariance is a pivot of modern physics of elementary particles. Standard model of elementary particles is a non-abelian gauge theory with the gauge group <span>(varvec{G=SU(3)otimes SU(2)otimes U(1)})</span>, that is the theory is constructed to be invariant under a gauge transformation <span>(varvec{psi (x) rightarrow U(x) psi (x)})</span>, where <span>(varvec{U(x)})</span> is a representation of <b><i>G</i></b> acting on matter fields <span>(varvec{psi (x)})</span> at a point <span>(varvec{xin mathcal {M}})</span> of some continuous differentiable manifold. The problem with extrapolation of gauge theories down to the Planck scales is that there is no continuous differentiable manifold in quantum gravity regime, and hence, neither the value of field at a point, nor a covariant derivative are defined in a usual way. We do such extrapolation assuming that our spacetime is a combinatorial spacetime, the points of which are the interaction vertices of matter fields. The vertices are connected to each other by matter particles. The gauge invariance then becomes a symmetry with respect to independent internal rotations of all fermion lines in the edges of the matter spin network graph. There is no need to introduce special gauge fields in this picture, since they are expressed in terms of fermion fields.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147561535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

{"title":"Dynamics of Quantum States Distinguishability in (mathcal{P}mathcal{T}) and (mathcal{A}mathcal{P}mathcal{T}) Qubits","authors":"Ali Moulhim,&nbsp;Ali Khairbek","doi":"10.1007/s10773-026-06314-4","DOIUrl":"10.1007/s10773-026-06314-4","url":null,"abstract":"<div><p>We investigate the distinguishability of qubits governed by <span>(mathcal{P}mathcal{T})</span>- and <span>(mathcal{A}mathcal{P}mathcal{T})</span>-symmetric Hamiltonians in both unbroken and broken phases. Analytical expressions for the time-dependent distinguishability are derived, showing that in the unbroken phase, both systems exhibit periodic oscillations. The oscillation period decreases with increasing Hermitian parameters or with decreasing non-Hermitian contributions, and the distinguishability reaches unity at integer multiples of this period. This work extends earlier studies on <span>(mathcal{P}mathcal{T})</span>-symmetric qubits by exploring more general <span>(mathcal{P}mathcal{T})</span>-symmetric Hamiltonians and by incorporating <span>(mathcal{A}mathcal{P}mathcal{T})</span>-symmetric qubits into the analysis.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147561348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}