Some problems have been found as to the definition of entropy of black hole S = A4 being applied to the extremal Kerr-Newman case, which has conflicts with the third law of thermodynamics. We have proposed a new modification for the near extremal one, which not only obeys the third law, but also does not conflict with other conclusions in black hole thermodynamics. Then we proved that the inner...

A link of information entropy and kinetic energy for quantum many-body systems. Abstract A direct connection of information entropy S and kinetic energy T is obtained for nuclei and atomic clusters, which establishes T as a measure of the information in a distribution. It is conjectured that this is a universal property for fermionic many-body systems. We also check rigorous inequalities previo...

The correlation entropy theory by Baranyai and Evans produces non-negligible entropy contributions arising from the four-body and even higher order terms of correlations. If we express this as S(x), the estimated value of S(x) is 0.6 (±0.1) NkB near the melting point when the structure factor of a liquid metal is of hard-sphere form (I. Yokoyama and S. Tsuchiya: Mater. Trans. 43 (2002) 67–72.)....

We discuss the (g0 φ )d self-interacting scalar field theory, in the strong-coupling regime. We assume the presence of macroscopic boundaries confining the field in a hypercube of side L. We also consider that the system is in thermal equilibrium at temperature β −1. For spatially bounded free fields, the Bekenstein bound states that the specific entropy satisfies the inequality S E < 2πR, wher...

the mechanical aspect of entropy-exergy relationship, together with the thermal aspect usually consid-ered, leads to an extended formulation of physical exergy based on both maximum useful work and maximum useful heat that are the outcome of available energy of a thermodynamic system. this approach suggests that a mechanical entropy can be studied, in addition to the already used thermal entrop...

We find a linear instability of non-axisymmetric Rossby waves in a thin nonmagnetized Keplerian disk when there is a local maximum in the radial profile of a key function L(r) ≡ F(r)S2/Γ(r), where F−1 = ẑ · (∇× v)/Σ is the potential vorticity, S = P/ΣΓ is the entropy, Σ is the surface mass density, P is the vertically integrated pressure, and Γ is the adiabatic index. We consider in detail the ...

One can increase one-quarter the area of a black hole, A/4, to exceed the total thermodynamic entropy, S, by surrounding the hole with a perfectly reflecting shell and adiabatically squeezing it inward. A/4 can be made to exceed S by a factor of order unity before the shell enters the Planck regime, though practical limitations are much more restrictive. One interpretation is that the black hol...

From the covariant bound on the entropy of partial light-sheets, we derive a version of Bekenstein’s bound: S/M ≤ πx/~, where S, M , and x are the entropy, total mass, and width of any isolated, weakly gravitating system. Because x can be measured along any spatial direction, the bound becomes unexpectedly tight in thin systems. Our result completes the identification of older entropy bounds as...

Anomaly detection is an essential component of the protection mechanisms against novel attacks. In this paper, we propose to use several information-theoretic measures, namely, entropy, conditional entropy, relative conditional entropy, information gain, and information cost for anomaly detection. These measures can be used to describe the characteristics of an audit data set, suggest the appro...