Narrow Results

We analyze structural parameters of the globular clusters belonging to the Milky Way system which were listed in the latest edition of the Harris Catalogue. We search for observational evidences of the effect of tidal forces induced by the Galaxy on the dynamical and thermodynamical evolution of a globular cluster. The behavior for the $W_0$ distribution exhibited by the globular cluster population seems to be in contrast with theoretical results in literature about gravothermal instability, and suggest a new limit value smaller than the previous one.

We have investigated dynamical evolution of electromagnetic perturbation in a scalar hairy black hole spacetime, which belongs to solutions in Horndeski theory with a logarithmic cubic term. Our results show that the parameter $\alpha$ affects the existence of event horizon and modifies the asymptotical structure of spacetime at spatial infinity, which imprints on the quasinormal frequency of electromagnetic perturbation. Moreover, we find that the late-time tail of electromagnetic perturbation in this background depends also on the parameter $\alpha$ due to the existence of solid angle deficit. These imply that the spacetime properties arising from the logarithmic cubic term in the action play important roles in the dynamical evolutions of the electromagnetic perturbation in the background of a scalar hairy black hole.

To examine the overall properties of the China’s stock market affected by the COVID-19 pandemic, we provide a comprehensive study of the multifractal properties across stock market sectors applying multifractal detrended fluctuation analysis (MF-DFA). We focus on intra-day 5min transaction data of 10 sectors in the Shanghai Stock Exchange, and the time-depended MF-DFA was also used to explore the dynamical evolution of the multifractal characterize for the overall period. We found that all sectors exhibit stronger multifractality and the weak market efficiency during the period of COVID-19, MHII performed best with the lower multifractal properties and higher market efficiency, three worse performers were ITII, TBII, and EII. While ITII, TBII, MCII, and UII were the four fastest recovering sectors from the gloom of the epidemic, with the plummeted multifractal intensity and the significantly increased market efficiency for the post-phase of the pandemic. The results based on the time-varying MF-DFA confirmed that the Chinese stock market is not only affected by the COVID-19 epidemic domestic but the impact of the US stock market crash in March was also transmitted to it, causing those industries sensitive to the market to fluctuate subsequently.

Considerable evidence supports the existence of many-body localization (MBL) phase transitions, although accurately determining the critical disorder intensity remains challenging due to significant instabilities in system size within the examined parameters. In this study, we employ the global quantum discord (GQD) to investigate MBL phase transitions and identify the critical points of the quantum Ising spin chain subjected to both disordered interacting and disordered external fields. Our analysis of GQD demonstrates its effectiveness in identifying the critical points between the thermal and the MBL phases. We further utilize the temporal evolution of GQD to comprehensively explore the characteristics of MBL phase transitions in the disordered quantum Ising spin chain. Our findings suggest that MBL phase transitions adhere to the same generality category based on the scaling analysis. Additionally, we investigate the effects of these examined parameters on the GQD and its dynamics and use them to estimate the critical points.

We present a mathematical framework (referred to as Context-driven Actualization of Potential, or CAP) for describing how entities change over time under the influence of a context. The approach facilitates comparison of change of state of entities studied in different disciplines. Processes are seen to differ according to the degree of nondeterminism, and the degree to which they are sensitive to, internalize, and depend upon a particular context. Our analysis suggests that the dynamical evolution of a quantum entity described by the Schrödinger equation is not fundamentally different from change provoked by a measurement often referred to as collapse but a limiting case, with only one way to collapse. The biological transition to coded replication is seen as a means of preserving structure in the face of context, and sexual replication as a means of increasing potentiality thus enhancing diversity through interaction with context. The framework sheds light on concepts like selection and fitness, reveals how exceptional Darwinian evolution is as a means of 'change of state', and clarifies in what sense culture (and the creative process underlying it) are Darwinian.

We analyze structural parameters of the globular clusters belonging to the Milky Way system which were listed in the latest edition of the Harris Catalogue. We search for observational evidences of the effect of tidal forces induced by the Galaxy on the dynamical and thermodynamical evolution of a globular cluster. The behavior for the W₀ distribution exhibited by the globular cluster population seems to be in contrast with theoretical results in literature about gravothermal instability, and suggest a new limit value smaller than the previous one.

We develop models of globular clusters (GCs) with a different approach by applying thermodynamic principles to a Boltzmann distribution function, with an Hamiltonian function which contains an effective potential depending on the kinetic energy of the stars, due to the effect of tidal interactions induced by the hosting galaxy. The Hamiltonian function is solution of the Fokker-Planck equation solved in a different way with respect to the King approach. Interesting results implying a different critical point for the onset of gravothermal catastrophe are presented, as well numerical simulations confirming the presence and the predicted form of the effective potential.

This work deals with the consequences which follow from the construction of a selfconsistent thermodynamical model of globular cluster. In so doing we are driven by the necessity of a star cluster model with density and pressure vanishing in correspondence of the surface of the system, whose finite radius is determined by the tidal force of the Galaxy. Considering the evolution of the selfgravitating system like a sequence of infinite equilibrium states, driven by reversible transformations, lead us to the introduction of an effective potential term, in the single particle Hamiltonian, taking into account the presence of the kinetic cutoff energy. The influence of the effective potential on the virial theorem will be described, together with the related consequences on the gravothermal stability limits for star clusters, explored through the linear series method for the equilibrium configurations. The effective potential description of the equilibrium models leads to some observational features, which allow to test the predicted critical central potential depth for the insurgence of the thermodynamical instability.