查看更多>>摘要：In our investigation,we explore the quantum dynamics of charge-free scalar particles through the Klein-Gordon equation within the framework of rainbow gravity,considering the Bonnor-Melvin-Lambda(BML)space-time background.The BML solution is characterized by the magnetic field strength along the axis of the symmetry direction which is related to the cosmological constant Λ and the topological parameter α of the geometry.The behavior of charge-free scalar particles described by the Klein-Gordon equation is investigated,utilizing two sets of rainbow functions:(ⅰ)f(x)=(eβx-1/βx),h(x)=1 and(ⅱ)f(x)=1,h(x)=1+βx/2.Here 0＜(x=|E|/Eq)≤1 with E representing the particle's energy,Ep is the Planck's energy,and β is the rainbow parameter.We obtain the approximate analytical solutions for the scalar particles and conduct a thorough analysis of the obtained results.Afterwards,we study the quantum dynamics of quantum oscillator fields within this BML space-time,employing the Klein-Gordon oscillator.Here also,we choose the same sets of rainbow functions and obtain the approximate eigenvalue solution for the oscillator fields.Notably,we demonstrate that the relativistic approximate energy profiles of charge-free scalar particles and oscillator fields get influenced by the topology of the geometry and the cosmological constant.Furthermore,we show that the energy profiles of scalar particles receive modifications from the rainbow parameter and the quantum oscillator fields by both the rainbow parameter and the frequency of oscillation.
查看更多>>摘要：Recently,reconsidering the Rastall idea Tμ;vv=a,μ through relativistic thermodynamics gives a new form for the scalar field a which led us to construct modem modified theory of gravity debugged'non-conserved gravity theory'Fazlollahi 2023 Euro.Phys.J.C 83 923.This theory unlike other modified theories of gravity cannot directly explain the current acceleration expansion in the absence of the cosmological constant and or existence of other forms of dark energy.Hence,in this study we have reinvestigated holographic dark energy ρx～H2 in the non-conserved theory of gravity.In this context,the density and pressure of dark energy depend on the non-conserved term and density of the dust matter field.As shown,due to non-conservation effects on large-scale structures,unlike the original holographic model,our model onsets an acceleration epoch for the current Universe satisfies observations.Moreover,the interaction and viscous scenarios are studied for this model.
查看更多>>摘要：This research paper presents a black hole solution with a rational nonlinear electrodynamics source within the Rastall gravity framework.The paper analyzes the thermodynamic properties of the solution in normal phase space and explores its critical behavior.The phase structure is examined using the extended first law of thermodynamics,with the cosmological constant Λ serving as pressure P.The isotherms exhibit van der Waals behavior at small values of horizon r+.The paper also investigates the Gibbs free energy behavior and finds two critical points with two pressures where the re-entrant phase transition occurs and disappears.We also explore the prevalent microstructure of black holes in Ruppeiner geometry,uncovering significant deviations in the nature of particle interactions from conventional practice.Moreover,the thermodynamic geometry is analyzed using the Ruppeiner formalism,with the normalized Ricci scalar indicating possible point-phase transitions of the heat capacity,and the normalized extrinsic curvature having the same sign as the normalized Ricci scalar.The three-phase transitions of the heat capacity are those that we find for the normalized Ruppeiner curvatures.Thus,there is an absolute correspondence.
查看更多>>摘要：In a previous paper[Phys.Rev.A 95,060 701(R)(2017)],we demonstrated that a new type of two-body interaction,which depends on the center of mass(CoM)momentum,can be realized for ultracold atoms via laser-modulated magnetic Feshbach resonance(MFR).Further studies(e.g.L He et al,Phys.Rev.Lett.120,045 302(2018))show that various interesting phenomena,such as Fulde-Ferrell superfluids,can be induced by scattering between ultracold atoms with this interaction.In this work we investigate the shallow bound states of two ultracold atoms with this type of interaction.We show that when the magnetic field B is below the MFR point Bo,two shallow bound states can appear in this system.Namely,a'two-component dimer'or a dimer with pseudo-spin 1/2 can be formed by two atoms.Furthermore,the dispersion curve of the dimer may have either single or double minimums in the CoM momentum space.The latter case can be explained as a result from significant pseudo-spin-orbital coupling(SOC)effects.Our results show that the ultracold gases with CoM momentum dependent interaction may be a candidate for quantum simulations with ultracold two-component molecules,especially the molecule gases with SOC.
查看更多>>摘要：The knots frequently occur in biopolymer and their diffusion plays an active role in the gene regulation.In this work,Langevin dynamics simulations were carried out to detect the diffusion behaviours of a knot along a tensioned polymer in different spatial constraints.The polymer accommodating a knot was tethered to two macrospheres to block the unravelling of the knot.As a result,the curves for the diffusion coefficients of the knot with different bending stiffness as a function of the tension in different spatial constraints were obtained.In the space without constraints or with weak constraints,the corresponding curves for the knot with relatively large bending stiffness exhibited two turnover behaviours.On the contrary,for the knot with relatively small bending stiffness,the diffusion coefficients were monotonically reduced with increasing tension.However,in a space with strong constraints,all the curves showed one turnover behaviour regardless of the bending stiffness.The turnover behaviours divided the curves into different regimes,and the dominant diffusion mechanisms in the regimes,namely,knot-region breathing,self-reptation,and internal friction,were clearly identified.The effective friction coefficients ζ of the knots with 31,41,51 and 52 types as a function of the knot size N at a fixed tension were well fitted by the relation ζ ∝ N.The effective friction coefficients of the knots at relatively large tension f＞3 sharply increased with the knot complexity,which is not dependent on the spatial constraints.By contrast,the values of these coefficients at relatively small tension f≤3 were remarkably dependent on the spatial constraints.Our work not only provides valuable simulation results to assist the understanding of the diffusion of DNA knot,but also highlights the single-molecule design for the manipulation of DNA knots in future.
查看更多>>摘要：Force spectrum measurements with constant loading rates are widely used in single-molecule manipulation experiments to study the mechanical stability and force response of biomolecules.Force-dependent transition rates can be obtained from the transition force distribution,but it is limited to the force range with non-zero force distribution.Although constant loading rate control can be realized with magnetic tweezers,the loading rate range is limited due to the slow movement of permanent magnets.Non-linear exponential and exponential squared force loading functions are more feasible in magnetic tweezers,while there is no theoretical result available for these two kinds of non-linear force loading functions.In this study,we solved the unfolding process of a protein following Bell's model under nonlinear exponential and exponential squared force loading functions,which offer a broader range of unfolding force distribution compared to the traditional constant loading rate experiments.Furthermore,we derived two force loading functions,which can produce uniform unfolding force distribution.This research contributes fundamental equations for the analysis of experimental data obtained through single-molecule manipulation under nonlinear force loading controls,paving the way for the use of nonlinear force control in magnetic tweezer experiments.
查看更多>>摘要：In this article a new achievement of fractional-order 3 x n Fan networks is presented.In the first step,the RT-I method is used to derive the general formulae of the equivalent impedance of fractional-order 3 × n Fan networks.In the second part,the effects of five system parameters(L,C,n,α and β)on amplitude-frequency and phase-frequency characteristics are analyzed.At the same time,the amplitude-frequency and phase-frequency characteristics of the fractional order 3 × n Fan network are revealed by Matlab drawing.This work has important theoretical and practical significance for resistor network models in the field of natural science and engineering technology.
查看更多>>摘要：This research focuses on the electric behavior of a mixed ferrielectric sulflower-like nanostructure.The structure includes a core with spin SiZ-1 atoms and a shell with spin σjZ-5/2 atoms.The Blume-Capel model and the Monte Carlo technique(MCt)with the Metropolis algorithm are employed.Diagrams are established for absolute zero,investigating stable spin configurations correlated with various physical parameters.The MCt method explores phase transition behavior and electric hysteresis cycles under different physical parameters.
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