International Journal of Theoretical Physics最新文献

We elaborate on the recent proposal of employing unitary operators in Quantum Mechanics. The Bell and Mermin inequalities for entangled coherent states are scrutinized by making use of the unitary displacement operators. A violation of the Mermin inequality close to the maximum allowed value is reported, in agreement with the existing literature.

Two novel schemes for symmetry deterministic cyclic controlled assisted cloning and asymmetry deterministic cyclic controlled assisted cloning by using a three-particle hyper-entangled state as the quantum channel are proposed in this paper. The first stage of scheme for symmetry deterministic cyclic controlled assisted cloning requires symmetry deterministic cyclic controlled teleportation. Three distant parties Alice, Bob and Charlie can simultaneous teleport an arbitrary unknown one-qubit state each other via Bell-state measurement, Hadamard operation, single-particle projective measurement, and appropriate unitary transformation. In the second stage of scheme for symmetry deterministic cyclic controlled assisted cloning, they can obtain a perfect copy of original unknown state with assistance from different state preparers, respectively. In the first stage of scheme for asymmetry deterministic cyclic controlled assisted cloning, Alice can teleport an arbitrary unknown two-qubit state at distant Bob’s site under the control of Charlie, Bob can teleport an arbitrary unknown four-dimensional single-particle state at distant Charlie’s site under the control of Alice, and Charlie can teleport an arbitrary unknown single-qubit state at distant Alice’s site under the control of Bob simultaneously. They can obtain a perfect copy of original unknown state with assistance from different state preparers in the second stage of scheme for asymmetry deterministic cyclic controlled assisted cloning, respectively.

The aim of this research is to explore the influence of fractional derivatives on solutions of various physical forms within a single mathematical model. By examining the Kadomtsev-Petviashvili-Benjamin-Bona-Mahony equation with the inclusion of temporal Atangana-conformable derivatives, and utilizing two effective methods, we observe distinct variations in the impact of the fractional derivative on altering the inherent physical properties of the proposed model. This research highlights an important function of the fractional derivative, indicating its role as a memory transmitter. This role illustrates how the physical characteristics inherent in the proposed application evolve as the value of the fractional derivative changes within the range of (0, 1) and nears that of the integer derivative. Finally, we provide illustrative 2D-plots to reinforce the findings of this study.

In this manuscript, we present a novel approach to constructing a distinct anisotropic solution for spherically symmetric spacetime. Our investigation focuses on the Buchdahl metric potential to solved Einstein’s field equations, and studied it for the cases of Buchdahl parameter K, when (Knotin [0,1]). We have obtained six different solutions and to show that our models fit with observational data, these solutions are analyzed for some known compact stars like EXO 1785-248, SMC X-1, LMC X-4, Her X-1, SAX J1808.4-3658, 4U 1538-52 and PSR B0941+10. The model satisfies all the physical as well as stability conditions, which verify the validity of the model. We have also explored the hydrostatic equilibrium for an uncharged case using the TOV equation. As strong evidence for more realistic and viable models, we have also provided graphical representations wherever required.

In this study, we discuss the evolution of the high-energy era of the universe in the background of f(Q) gravity. For this purpose, the constant-roll condition is considered in the early universe dynamics. After the unified solution of the field equations, the early universe era is analyzed through model parameters in the framework of the constant-roll inflationary field. Along with it is compatible with the observation data, it has been determined that the universe evolved from the initial quasi-de Sitter vacuum state to a quintessence vacuum within the framework of observational data. It is observed that this occurs when the constant-roll parameter is fixed in the parameter space.

This article employs the Shehu Adomian decomposition method to derive approximate solutions for the time-fractional Belousov-Zhabotinsky system, a phenomenon prevalent in the field of thermodynamics. This model offers a deep understanding of the core principles of nonlinear dynamics in intricate systems. This model is additionally employed to investigate bifurcations, chaotic dynamics, and other nonlinear phenomena in chemical processes. The advantage of the suggested method is that, unlike the usual Adomian process, it doesn’t involve figuring out the fractional derivative or integrals in the recursive mechanism. This makes it simple to evaluate series terms. We present Caputo, Caputo-Fabrizio, and Atangana-Baleanu in the Caputo sense fractional derivatives with the proposed method to enhance the comprehension of this intricate mechanism. We have presented various 2D and 3D graphical visualizations of the obtained solutions to demonstrate the model behaviour and the effects of the derived results by varying the fractional order. The obtained results are highly consistent with the q-homotopy analysis transform method, the fractional reduced differential transform method, and the double Laplace transform method. We also present the convergence and uniqueness of the proposed system. The results obtained with the proposed method indicate that it is simple to implement and computationally very attractive.

We construct a lot of optimal or near-optimal ([n,k,d]_9) Hermitian self-orthogonal codes for (kle 3) using norm codes and matrix combinatorial construction method. As an application, we construct nine families of entanglement-assisted quantum error-correcting codes. Some of these codes can achieve q-ary linear EA-Griesmer bound with better parameters than those in the literature.

Nonlinear electrodynamics has been frequently employed in the study of black holes. Some of these black holes may be regular, while others are singular. In this work, we consider a nonlinear electrodynamics model known as inverse electrodynamics to obtain black hole solutions. We demonstrate that, in addition to these solutions not being regular, they are also not asymptotically flat. We investigate which energy conditions are violated in the presence of this type of source. Furthermore, we calculate thermodynamic quantities and find that there are two phases, with one of them being thermodynamically stable. Finally, we derive the geodesics for massive and massless particles in this spacetime. For the massive case, we observe that there are no bound orbits.

The (C^3) approach is an invariant formalism that utilizes the eigenvalues of the Riemann curvature tensor to match spacetimes across a specific matching surface. We apply this approach to match an anisotropic fluid with an exterior vacuum solution, including the case in which discontinuities appear on the matching surface. As a particular example, a class of analytic solutions, which describe the gravitational field of realistic neutron stars, is matched to the exterior Schwarzschild spacetime.

In the development of quantum technologies, nonclassical states have been playing a pivotal role, as quantum advantage cannot be obtained without appropriate utilization of nonclassicality. In the present work, we consider a hybrid coherent state (HCS), which is a coherent superposition of the single-photon-added coherent (SPAC) state and a coherent state (CS). Here, we report higher-order nonclassical properties of HCS with a specific focus on higher-order squeezing, higher-order antibunching and higher-order sub-Poisssonian photon statistics. It’s shown that HCS is experimentally realizable, and this engineered quantum state can be used to produce quantum states with desired higher-order nonclassical properties.