Fortschritte Der Physik-Progress of Physics最新文献

A theory of two-dimensional Bloch–Landau–Zener (BLZ) oscillations of wavepackets in incommensurate moiré lattices under the influence of a weak linear gradient is developed. Unlike periodic systems, aperiodic lattices lack translational symmetry and therefore do not exhibit a conventional band-gap structure. Instead, they feature a mobility edge, above which (in the optical context) all modes become localized. When a linear gradient is applied to a moiré lattice, it enables energy transfer between two or several localized modes, leading to the oscillatory behavior referred to as BLZ oscillations. This phenomenon represents simultaneous tunneling in real space and propagation constant (energy) space, and it arises when quasi-resonance condition for propagation constants and spatial proximity of interacting modes (together constituting a selection rule) are met. The selection rule is controlled by the linear gradient, whose amplitude and direction play a crucial role in determining the coupling pathways and the resulting dynamics. A multimode model describing BLZ oscillations in the linear regime is derived, and effects of both attractive and repulsive nonlinearities on their dynamics are analyzed. The proposed framework can be readily extended to other physical systems, including cold atoms and Bose–Einstein condensates in aperiodic potentials.

A quantum-corrected black hole metric has been derived in [Lewandowski et al., Phys. Rev. Lett. 130 (2023) 10, 101501] within the context of the quantum Oppenheimer–Snyder model inspired by loop quantum cosmology. Using the Frobenius method, we have obtained precise values for the fundamental quasinormal modes and the first few overtones for scalar and electromagnetic perturbations. Our results reveal that, unlike the fundamental mode, the overtones exhibit high sensitivity to quantum corrections, leading to qualitatively new spectral behavior. Notably, our findings suggest that modes with real oscillation frequencies approaching zero appear in the spectrum. The existence of arbitrarily long-lived modes, known as quasi-resonances is also demonstrated.

Linear background fluxes offer a unified origin for non-commutative and non-associative geometries in string and M-theory. Revisiting the open string with a linearly varying Kalb–Ramond field, we recover kappa-Minkowski space as a Jordanian deformation of Poincaré symmetry. Lifting the construction to an open M2-brane in a linear three-form background yields a kappa-Nambu triple bracket that realises the three-Lie algebra of the Bagger–Lambert–Gustavsson model and exposes an underlying quasi-Hopf two-algebra. A Bopp-shift quantisation reveals that isotropic potentials are unaltered at leading order, whereas anisotropic ones receive Planck-suppressed corrections, and gerbe holonomy discretises the deformation scale. Inspired by the membrane bracket, we build a cubic-matrix extension of the BFSS model whose higher-Lie structure supplies the long-missing five-brane central charge and reproduces the expected $�N^3$ energy scaling of coincident M5-branes. These results establish linear fluxes as the minimal ingredients that interpolate smoothly from Moyal to Lie and Nambu deformations, providing concrete, anomaly-free models for non-associative field theories and five-brane dynamics.

Quantum coherence and phase transitions are studied in a finite one-dimensional Bose–Hubbard model using exact diagonalization under thermal fluctuations, a Stark potential, and disorder. The condensate fraction, superfluid fraction, visibility, number fluctuations, and the $�{\ell }_1$-norm of coherence are computed to characterize the Mott insulator–superfluid transition. Although finite-size effects prevent a sharp transition, ground-state properties reveal signatures of quantum criticality. Thermal fluctuations can enhance coherence via tunneling, a Stark potential promotes localization, and disorder suppresses global superfluidity while preserving local coherence. These results highlight how disorder, tilt, and temperature reshape coherence and offer insights for quantum simulation and strongly correlated phases. For systems up to six sites with unit filling, a spectral analysis is also performed through the metric mean gap ratio (MGR). However, limited statistics due to the small system size and computational constraints prevent a complete characterization of quantum chaos, yielding only approximate signatures.

The relation between the vertex operators of the in and out fields in Liouville theory is analyzed. This is used to derive equations for the S-matrix, from which a recursive relation for the normal symbol of the S-matrix for discrete center-of-mass momenta is obtained. Its solution is expressed as multiple contour-integrals of a generalized Dotsenko–Fateev type. This agrees with the functional integral representation of the scattering matrix of Liouville theory, which had been proposed previously.

To effectively utilize the AdS/CFT correspondence, a precise set of rules must be established to guide the translation of computed quantities in the gravitational sector into their CFT counterparts, and vice versa. This framework is commonly referred to as the holographic dictionary. The formulation of such dictionaries opens a two-way gateway, allowing researchers to extend theoretical principles and findings from one domain into the other for further exploration and study. The development of a holographic dictionary for Lifshitz black holes and hyperscaling violation (HSV) models has provided an essential foundation for studying CFT thermodynamics and phase behavior of these black holes. Based on this framework, the study will investigate their thermodynamic properties using two distinct approaches. In the first step, the work adopts the classical and traditional method, identifying critical points to examine the behavior of the free energy function as a function of temperature near the critical boundary. By analyzing its behavior, the work will study phase transitions and then proceed to evaluate the stability of the models. In the next step, to compare both methodologies and highlight their equivalence—particularly demonstrating the accessibility of the topological method compared to the classical approach—the study will analyze phase behavior through the lens of topological charges.

This work is explored the black hole information loss paradox, a fundamental challenge in theoretical physics. Insights are proposed using Holographic Entanglement Entropy (HEE) and the AdS/BCFT correspondence within Horndeski gravity. The work is revisited the time-dependent behavior of HEE to probe black hole interiors and examines its implications for the Page curve, which is described the entropy evolution of Hawking radiation. The relationship between conformal field theory (CFT) microstates and black hole thermodynamics through the AdS/BCFT correspondence is also discussed, suggesting that only a subset of microstates corresponds to black holes with smooth interiors, while others may involve firewalls. Black hole thermal entropy is extended to time-dependent entanglement entropy, offering a perspective on the interplay between quantum mechanics, thermodynamics, and gravity.