物理最新文献

Using the AMPT model, we study charged hadron elliptic flow ((v_{2})) centrality dependence in Au+Au collisions at (sqrt{s_{NN}}=200~textrm{GeV}). We find distinct centrality-dependent roles for partonic ((sigma _{p})) and hadronic ((sigma _{H})) transport processes. In central collisions, (v_{2}) is dominantly amplified by larger (sigma _{p}) (reducing partonic viscosity) but insensitive to (sigma _{H}). In peripheral collisions, larger (sigma _{H}) (reducing hadronic viscosity) significantly enhances (v_{2}), flattening its centrality dependence and improving agreement with STAR data. Initial pressure gradients (enhanced by Lund parameter (a_{L})) also increase (v_{2}), while (b_{L}) affects spectra but not flow. This centrality-differential sensitivity to (sigma _{p}) and (sigma _{H}) provides a novel strategy for extracting phase-specific shear viscosities.

In the region of superheavy nuclei, where experimental data are scarce, theoretical calculations of separation energies and masses are vital for understanding their properties and potential stability. In this work, we calculate the proton and neutron separation energies for superheavy nuclei in the framework of a two-body model. To this aim, we first consider a nucleus as a two-body system, so using the Schrödinger equation in the presence of a nonrelativistic potential including the magnetic moments and Coulomb interactions, we determine the mass equation of the nuclei, analytically. Having the analytical solutions, we compute the ground-state mass of superheavy nuclei including Rf, Db, Sg, Bh, Hs, Mt, Ds, and Rg as well as the one- and two-nucleon separation energies. Our theoretical results are compared with the existing experimental data.

Background

In audio and speech signal processing, speech enhancement is thought of as a significant task. Speech improvement intends to improve the accessibility and excellence of an audio signal that has been weakened by ambient noise. The research on speech enrichment is the toughest process because of the degree of degradation of the speech signals. Diverse strategies for speech improvement are used based on the type of weakening and noise in the speech signal. As a result, the research in this area is still difficult, particularly when handling reverberation and extremely irregular noise. In this study, an enhanced speech enhancement framework is created using optimized deep learning techniques to improve both the quality and clarity of speech signals. At first, the required speech signal is collected from online resources. Further, the collected speech signal is directly passed to atrous convolution-based adaptive Trans-UNet (ACAT-UNet) with a novel loss function to attain the enhanced speech signal. Here, the loss function is incorporated with the deep learning model to enhance speech intelligibility. Furthermore, the speech enhancement performance of the ACAT-UNet is enhanced by fine-tuning the hyperparameters using the Updated Randomized Variable-based Aquila Optimizer (URVAO). The efficacy of the recommended speech improvement system is evaluated by conducting extensive simulations and experiments by contrasting it with other existing SE techniques. The numerical findings revealed that the suggested approach attained a root mean square error (RMSE) value of 0.226779.

This study investigates the construction and stability of thin-shell wormholes derived from the modified Bardeen anti-de Sitter (AdS) black hole. The thin-shell wormhole is constructed using Visser’s cut-and-paste method, which involves matching two identical black hole spacetimes at a hypersurface to form a throat that connects the geometries. Wormhole’s stability is examined through the Israel formalism, which provides the surface stress-energy tensor at the throat. The violation of energy conditions, a hallmark of exotic matter, is explored in detail. Linearised stability analysis is performed by perturbing the wormhole throat and analysing the resulting equations of motion. Various equations of state (EoS), including barotropic, generalised phantom-like, and generalised Chaplygin gas models, are considered to study the behaviour of the system under radial perturbations. Our findings demonstrate that a thin-shell wormhole’s stability strongly depends on the throat radius, charge parameters, and cosmological constant. Furthermore, the influence of EoS parameters is crucial in determining the stable and unstable configurations of the wormhole. This study highlights the critical role of modified black hole geometries in constructing physically viable and stable wormhole solutions in the context of AdS spacetimes.

In the present work, we intend to study the Ramsauer–Townsend effect in the scattering of muon by light and heavy nuclei. This scattering provides a precise probe of nuclear charge and matter distributions, playing a critical role in testing nuclear structure models and refining fundamental interaction theories. For our purpose, we investigate the scattering of muon in the framework of generalized uncertainty principle (GUP). We first derive the modified nonrelativistic and relativistic wave equations due to the minimal length in the GUP framework and then determine the wave function of the incident particle by applying the scattering potential due to the nuclear mean field. In the following, we calculate the transmission and reflection probabilities from the square potential well. Finally, the Ramsauer–Townsend effect will be studied, and it will be shown that some exotic phenomena occur in this framework, which cannot be explained by conventional quantum mechanics.

In data-driven determination of Parton Distribution Functions (PDFs) in global QCD analyses, uncovering the true underlying distributions is complicated by a highly convoluted inverse problem. The determination of PDFs can be understood as the inference of a function supported on [0, 1], a problem that admits multiple acceptable solutions. An ensemble of solutions exists that pass all standard goodness-of-fit criteria. In this paper, we propose algorithms for the classification, clustering, and selection of solutions to the determination of PDFs, or any functions on [0, 1], based on the characterization of their shape. We explore information-theoretic based (Rényi entropy and divergence) and optimal-transport based (Wasserstein distance) criteria. In particular, we advocate for the use of the Rényi entropy as an absolute estimator per solution, as opposed to relative estimators that compare solutions pairwise. We show that the Rényi entropy can characterize the space of solutions w.r.t. the PDF shapes. Paired with the identification of the optimal combination of solutions via Pareto fronts, it provides a plausible and minimalist selection algorithm. Moreover, Rényi entropy proves versatile for use in clustering applications.

The effect of gravity is a key factor in understanding the physical phenomenon. Quantizing gravity is challenging task due to weak interactions of gravity in quantum world. The quantum nature of gravity can be witnessed by entanglement in an interferometric platform [Phys. Rev. D 105, 086024 (2022)]. A natural question arises concerning whether the quantization of gravity can be observed via other means. In this work, we propose an effective approach to witnessing the gravity-induced quantumness by quantum uncertainty relations, including entropy-based and coherence-based uncertainty relations. The theoretical frameworks for wave-particle, entropic uncertainty and coherence are established, which can prove the quantum nature of gravity. The three-measurement entropic uncertainty and coherence exhibit the oscillatory features for the gravity-induced phases in the interferometric scheme. It is found that the evolutionary dynamics of coherence is inversely correlated with the measured uncertainty. It can be interpreted that the reduction of systemic quantum resource leads to the increase of entropic uncertainty, and vice versa. When the entropic uncertainty reaches zero, systemic coherence is the maximum value, providing a viable physical explanation for the gravity-induced quantumness. It shows that the entropic uncertainty and coherence can be regarded as the reliable indicators for capturing the gravity-induced quantumness. Compared to entanglement-based gravity quantization scheme, it shows that the capabilities are equivalent for detecting the gravity-induced quantumness using entropy uncertainty, coherence, and entanglement. The results could lay a solid theoretical foundation for the potential applications of quantum gravity in quantum information science.

In this paper, we perform small perturbations around the circular timelike orbit in the equatorial plane of the Horndeski rotating black hole, and analyze the effects of Horndeski hair on the three fundamental frequencies of the epicyclic oscillations. Since this operation can model the quasiperiodic oscillations (QPOs) phenomena of the surrounding accretion disc, we then employ the MCMC simulation to fit the theoretical results with three QPO events, including GRO J1655-40, XTE J1859+226 and H1743-322, and constrain the characteristic radius r, black hole mass M and spinning parameter a, and the Horndeski hair parameter h. Our constraint on the Horndeski hair parameter is much tighter than QPOs simulation from the existed accretion models, suggesting slight deviation from classical Kerr black hole.

In this work, we construct new classes of topological black hole solutions in anti-de Sitter (AdS) spacetime using a novel model of nonlinear electrodynamics called Modification Maxwell (ModMax) and Modification phantom or Modification anti-Maxwell (ModAMax). We then evaluate the thermodynamic quantities and verify the first law of thermodynamics. Our study examines how the parameters of the ModMax and ModAMax fields, as well as the topological constant, affect the black hole solutions, thermodynamic quantities, and local and global thermal stabilities. Furthermore, within the framework of extended phase space thermodynamics, we analyze the Joule–Thomson expansion process and determine the inversion curves. This analysis reveals that the ModMax and ModAMax parameters significantly alter the cooling and heating behavior of these AdS black holes, depending on their topology. Finally, by treating these topological Mod(A)Max AdS black holes as heat engines, we assess their efficiencies, demonstrating that the parameters of nonlinear electrodynamics and horizon topology play crucial roles in enhancing or suppressing the system’s thermodynamic performance.