International Journal of Theoretical Physics最新文献

{"title":"Minimal Length: A Source of Quantum Non-Locality","authors":"H. Moradpour,&nbsp;S. Jalalzadeh","doi":"10.1007/s10773-026-06520-0","DOIUrl":"10.1007/s10773-026-06520-0","url":null,"abstract":"<div><p>The narrow and subtle difference between the Hilbert spaces of operators corresponding to the canonical momentum and the generalized momentum that includes minimal length effects is polished. Consequently, complex eigenvalues may be allowed for the canonical momentum operator due to the existence of minimal length. A novel quantum entanglement generation is also reported indicating the power of theories including a minimal length in enriching the current understanding of quantum non-locality.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 11","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338780","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":"Riemann–Hilbert Approach to the Modified Zakharov–Kuznetsov Equation: Solitons, Breathers and Degenerate Rogue-Type Structures in a Magnetized Plasma","authors":"Sourav Das,&nbsp;Debjit Dutta","doi":"10.1007/s10773-026-06523-x","DOIUrl":"10.1007/s10773-026-06523-x","url":null,"abstract":"<div><p>The modified Zakharov–Kuznetsov (mZK) equation governs weakly nonlinear ion-acoustic and dust-acoustic waves in a magnetized plasma whose quadratic nonlinearity is suppressed by the background composition. Writing <span>(varvec{B})</span> and <span>(varvec{C})</span> for its parallel and transverse dispersion coefficients, we show that in the obliquely propagating sector <span>(varvec{zeta =x+my})</span>, where <span>(varvec{m=tan theta })</span> measures the obliqueness of the wave normal, the anisotropic mZK equation collapses exactly onto the focusing modified Korteweg–de Vries equation. The two dispersion coefficients enter only through the single effective dispersion <span>(varvec{D=B+Cm}^{varvec{2}})</span>, and the magnetic field only through <span>(varvec{C/B=1+Omega }^{varvec{-2}})</span>, with <span>(varvec{Omega })</span> the ion-cyclotron frequency normalized to the ion plasma frequency. This places the inverse-scattering apparatus at our disposal. We construct the <span>(varvec{2times 2})</span> Ablowitz–Kaup–Newell–Segur Lax pair, verify the zero-curvature condition, and establish the analyticity and symmetry properties of the Jost solutions. A matrix Riemann–Hilbert problem is posed on the real spectral axis, its jump matrix derived explicitly and its solution shown to be unique by a vanishing lemma. In the reflectionless case the problem reduces to a finite algebraic system and the <span>(varvec{N})</span>-soliton family is written through a single complex <span>(varvec{tau })</span>-function. Purely imaginary eigenvalues give oblique line solitons, conjugate pairs give breathers, and the coalescence of a conjugate pair gives a degenerate double-pole structure whose peak transiently doubles the soliton amplitude. At fixed amplitude, obliqueness and weak magnetization broaden a structure as <span>(varvec{sqrt{D}})</span> while leaving its front speed unchanged.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 11","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338267","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":"Black Holes in a Non-Shift-Symmetric Horndeski Model: Consistency Conditions and Physical Diagnostics","authors":"Adnan Malik,&nbsp;Jamshed Khan,&nbsp;Ahdab K. Althukair,&nbsp;Hina Zahir","doi":"10.1007/s10773-026-06516-w","DOIUrl":"10.1007/s10773-026-06516-w","url":null,"abstract":"<div><p>We examine the consistency requirements for static, spherically symmetric black holes in the Horndeski subclass <span>(G_2=eta X+2Lambda )</span>, <span>(G_4=(16pi G)^{-1}+beta phi ^2)</span>, and <span>(G_3=G_5=0)</span>. A scalar field linear in time is compatible with a static metric in some shift-symmetric theories, but that construction cannot be transferred automatically to a coupling with explicit scalar dependence. Requiring the full metric equations to hold at every time forces a Ricci-flat metric when <span>(beta q^2ne 0)</span>; the stated asymptotically flat scalar boundary conditions then conflict with a nonzero <i>q</i> for <span>(eta ne 0)</span> and <span>(Lambda =0)</span>. We correct the variational equations and horizon boundary conditions, formulate radial and non-radial null-convergence diagnostics, and distinguish a test-scalar wave equation from a coupled gravitational stability calculation. We also derive the photon-sphere and innermost stable circular orbit diagnostics and explain why percent-level geometric differences alone do not establish detectability. The previously reported hairy branch, mode frequencies, and shadow and orbital shifts require recalculation and are not used to claim existence, linear stability, or observational distinguishability.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 11","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338255","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":"Variable-step Discrete-time Quantum Walks on Binary Tree","authors":"Qi Han,&nbsp;Ziyi Ma,&nbsp;Xuexin Huang,&nbsp;Xiao Wu,&nbsp;Junlin Li","doi":"10.1007/s10773-026-06317-1","DOIUrl":"10.1007/s10773-026-06317-1","url":null,"abstract":"<div><p>In this paper, we present an analytical framework for variable-step discrete-time quantum walks (DTQWs), focusing on their complexity characteristics and resource scaling. Focusing on the exponentially decaying step sequence framework, we analyze how the walker’s probability distribution forms a binary tree (BT) topology in the position space, thereby realizing super-ballistic diffusion. Through analytical derivations and numerical simulations, we verify that the time complexity for covering a <i>d</i>-dimensional Hilbert space is reduced from the linear <i>O</i>(<i>d</i>) to the logarithmic <span>(O(log d))</span>, and confirm that the resource consumption of non-identity coin operations follows the linear <i>O</i>(<i>d</i>) scaling. These results provide a mathematically solid verification for the efficiency of variable-step quantum walks, and also lay a clear theoretical foundation for their application in high-dimensional quantum information processing.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 11","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338256","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":"Geometric Formulation for Palatini-Cartan Gravity","authors":"Jasel Berra-Montiel,&nbsp;Ivan Cortes-Cruz,&nbsp;Alberto Molgado","doi":"10.1007/s10773-026-06519-7","DOIUrl":"10.1007/s10773-026-06519-7","url":null,"abstract":"<div><p>Motivated by the increasing efforts to understand the covariant structure of physical models associated with General Relativity using different kinds of geometric frameworks, such as multisymplectic or polysymplectic manifolds, in this article we analyze the four-dimensional Palatini-Cartan model for gravity, which stands for a generalization for General Relativity that provides a natural structure for treating the co-frame field and the connection as independent variables, from the novel and mathematically well-defined perspective of various geometric-covariant formalisms for classical field theory inspired by these types of geometric structures. At the Lagrangian level, we do not only obtain the field equations of the theory, which are equivalent to the torsion-free condition and the Einstein equations, but we also study the gauge symmetries of the model in order to construct the Lagrangian momentum map associated with the action of the gauge symmetry group on the configuration space of the system and, consequently, its corresponding Noether currents. Within the multisymplectic approach, we analyze the action of the gauge symmetry group on the multimomentum phase space of the model, and we also introduce the induced momentum map that allows us to recover the admissible Cauchy data of the system. Besides, we apply the algorithm to treat singular systems within the polysymplectic framework, in which, in order to obtain the correct field equations of the model, we introduce a non-trivial Dirac-Poisson bracket peculiarly characterized by the Moore-Penrose generalized inverse of the matrix induced by the second-class constraints of the system. Finally, using the multisymplectic framework as a starting point, we perform the space plus time decomposition of the system to recover the instantaneous Lagrangian and the extended Hamiltonian of the theory, as well as the gauge structure that characterizes the Palatini-Cartan model for gravity within the instantaneous Dirac-Hamiltonian formalism.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 11","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338304","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":"Dual-horizon Topological Thermodynamics of a Kerr–Newman–de Sitter Black Hole in Bumblebee Gravity","authors":"Abdelhay Salah Mohamed,&nbsp;Aqsa Mehmood,&nbsp;M. Umair Shahzad,&nbsp;Muhammad Zeshan Ashraf","doi":"10.1007/s10773-026-06515-x","DOIUrl":"10.1007/s10773-026-06515-x","url":null,"abstract":"<div><p>This work is devoted to study the topological classification of a Kerr-Newman-de Sitter (KNdS) black hole (BH) in bumblebee gravity (BBG) subject to changes in various parameters. Based on generalized free energy techniques coupled with Duan’s <span>(phi )</span> mapping topological current theory, we find that BH can be separated into different topological classes. Interestingly, our result demonstrates that the existence of a number of horizons in dS spacetime, in particular, we find that both the event horizon and the cosmological horizon carry two zero points with opposite winding numbers, so that each horizon has vanishing total topological number, <span>(W_h=W_c=0)</span>. The winding-number assignment of the two cosmological-horizon defects is reversed relative to the event horizon, and this classification is unchanged by the electric charge <i>Q</i> and the Lorentz-violation parameter <i>L</i>.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 11","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338356","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":"Quantizing Gravitational Fields with an Entropy-Corrected Action Principle","authors":"Jianhao M. Yang","doi":"10.1007/s10773-026-06518-8","DOIUrl":"10.1007/s10773-026-06518-8","url":null,"abstract":"<div><p>A variational framework for the quantization of gravitational fields is developed through an extension of the classical stationary action principle. With this framework, the Wheeler–DeWitt equation for the gravitational wave functional is derived rather than postulated by promoting the Hamiltonian to an operator, as in canonical quantization. The formulation is motivated by information-theoretic considerations and incorporates a correction to the classical action constructed from the relative entropy characterizing the fluctuations of the gravitational fields. This entropy contribution is introduced within an ensemble formulation on a superspace. The ensemble formulation is subsequently extended to provide a unified treatment of quantization and constraints, addressing the long-standing ambiguity associated with the ordering between quantization and constraint reduction. The results also avoid the operator-ordering ambiguities inherent in canonical quantization. The framework is then applied to gravitational fields coupled to a massless scalar field. By introducing an emergent time parameter defined by the rate equation of gravitational fields, a Schrödinger equation for the scalar-field wave functional is obtained together with an additional quantum correction term of order <span>(Ghbar ^2)</span>. Finally, possible connections between the relative entropy underlying the present framework and the holographic aspects of quantum gravity are discussed.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 11","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10773-026-06518-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149339505","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":"Dynamics of Atom-Atom Correlations in the Three-Atom Multiphoton Tavis-Cummings Model","authors":"Eugene Bashkirov,&nbsp;Alexander Bagrov","doi":"10.1007/s10773-026-06513-z","DOIUrl":"10.1007/s10773-026-06513-z","url":null,"abstract":"<div><p>An exact analytical solution of the nonstationary Schrödinger equation is presented for the three-atom multiphoton Tavis-Cummings model with a vacuum cavity field, and is extended to a thermal field of arbitrary intensity via thermal averaging. The solution is valid for an arbitrary pure initial atomic state and arbitrary photon transition multiplicity. Based on this solution, analytical formulas for two measures of quantum correlations, pairwise negativity and symmetric quantum discord, are derived for two-atom density matrices of X-form. A numerical analysis is performed for a wide class of initial states: biseparable, W- and GHZ-type states, in both vacuum and thermal cases. The photon transition multiplicity serves as an effective control parameter for selective generation of quantum correlations. Increasing this parameter can symmetrize quantum and classical correlation dynamics, stabilize their behavior, and suppress both sudden death of pairwise entanglement and switching of the optimal projective measurement. For certain initial states, analytical expressions for the sudden death of entanglement time intervals are obtained, in which the symmetric quantum discord remains nonzero. In the thermal case, the symmetric quantum discord either stabilizes, grows with mean photon number for the GHZ-state, or is suppressed for initially uncorrelated pairs, while the pairwise negativity vanishes. The thermal field can both simplify and complicate the optimal measurement strategy, depending on the initial atomic state. The results can be applied in quantum information processing protocols requiring controlled generation of quantum correlations, and establish limits on the times of three-atom operations in the considered cavity quantum electrodynamics model.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 11","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338834","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":"Investigation and Adaptive Entanglement Optimisation of Open Quantum Systems Near Schwarzschild Black Holes","authors":"Cookey Iyen,&nbsp;Babatunde James Falaye","doi":"10.1007/s10773-026-06514-y","DOIUrl":"10.1007/s10773-026-06514-y","url":null,"abstract":"<div><p>Quantum entanglement is fundamental to many quantum systems but is vulnerable to environmental interactions that induce decoherence. This study investigates the entanglement properties of three initially entangled Dirac field modes labelled as subsystems A, B and C when mode C encounters the Hawking radiation of a Schwarzschild black hole. The effects of increasing Hawking temperature, <span>(T_H)</span>, on global coherence, the purity of the localised field mode <i>C</i>, and logarithmic negativity across the bipartitions were examined. The results show that the coherence of the total system decreases from approximately 1 to 0.85 as <span>(T_H)</span> increases, while the Purity of particle <i>C</i> increases slightly from about 0.50 to 0.552. Logarithmic negativity across the <span>(C_1|AB)</span> bipartition decreases to about 0.76, whereas the <span>(A|BC_1)</span> and <span>(B|AC_1)</span> bipartitions decrease only to about 0.86, demonstrating that the field mode that encounters the Hawking radiation from the black hole experiences the greatest entanglement degradation. No entanglement sudden death was observed within the parameter range considered. A noteworthy result of this research is the identification of an optimised initial-state engineering strategy for adaptive entanglement protection under Hawking degradation. It is shown that the maximally entangled GHZ state may not be optimised for preserving multipartite entanglement in the presence of relativistic noise, the GHZ weighting parameter <span>(theta )</span> was further optimised to maximise the surviving log-negativity across the most vulnerable bipartition <span>(C_1|AB)</span>. The optimal <span>(theta )</span> varies from <span>(45^circ )</span> to <span>(52.57^circ )</span> with increasing <span>(T_H)</span> yielding up to a <span>(3.66%)</span> enhancement in logarithmic negativity in the high-temperature limit for the bipartition <span>(C_1|AB)</span>. The corresponding asymptotic Hawking-optimised GHZ state is approximately <span>(|{psi _{textrm{HOGHZ}}}rangle approx 0.6078,|{000}rangle +0.7941,|{111}rangle . )</span> <span>(|{psi _{textrm{HOGHZ}}}rangle )</span> optimises the log-negativity of the bipartition <span>(C_1|AB)</span> in the high temperature limits.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 11","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338833","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":"The Contextual Modal Logic of a Wigner’s Friend Generalization","authors":"Felipe D. Alves,&nbsp;João C. A. Barata","doi":"10.1007/s10773-026-06501-3","DOIUrl":"10.1007/s10773-026-06501-3","url":null,"abstract":"<div><p>Quantum mechanics has been subject to logical scrutiny since its inception. The behavior of quantum systems, which are fundamentally dissimilar from classical systems, often appears to point to a logical inconsistency in quantum mechanics, allegedly leading to contradictions in the prediction of experimental measurements–though such contradictions have never materialized. A recent example of this type of inquiry into the logical well-posedness of quantum mechanics is the Frauchiger–Renner Gedankenexperiment, which purports to demonstrate that quantum mechanics is logically inconsistent under trivial assumptions. In this article, we show that by considering the property of contextuality in quantum systems–as predicted by the Kochen–Specker theorem–the supposed contradiction proposed by Frauchiger and Renner becomes logically inaccessible.</p></div>","PeriodicalId":597,"journal":{"name":"International Journal of Theoretical Physics","volume":"65 11","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10773-026-06501-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338832","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}