Thermodynamic stability, critical points, and phase transitions in the theory of partial distribution functions

Among many open questions in theoretical physics, consistent quantum gravity theory is still a major issue to be solved. Recent major works in phase transitions of black holes (BH) can be helpful for quantum interpretation of classical gravity. We study the new effective method to discuss the thermodynamic phase transitions onto well renowned regular BHs. Ordinary approaches of phase transitions depend upon equation of state and it is impossible to obtain all critical points with ordinary approaches. This study is derived from the slope of temperature versus entropy and it provides the possibility of finding all the critical points analytically. This technique provides pressure, which is different from standard relation of pressure and independent of other thermodynamical relations. We discuss some issues in ordinary methods and provide an easy approach to investigate the critical behavior of thermodynamical quantities. We find out the phase transitions points and horizon radii of non-physical range for BHs. We also use the new thermodynamical relations to briefly study well-known Joule–Thomson (JT) effect on regular BH.

Download Full-text

CUMULATIVE MEASURE OF CORRELATION FOR MULTIPARTITE QUANTUM STATES

International Journal of Modern Physics B ◽

10.1142/s0217979214500507 ◽

2014 ◽

Vol 28 (07) ◽

pp. 1450050 ◽

Cited By ~ 2

Author(s):

ANDRÉ L. FONSECA DE OLIVEIRA ◽

EFRAIN BUKSMAN ◽

JESÚS GARCÍA LÓPEZ DE LACALLE

Keyword(s):

Phase Transitions ◽

State Space ◽

Present Article ◽

Critical Points ◽

Quantum Phase Transitions ◽

The State ◽

Quantum States ◽

Quantum Phase ◽

Mixed States ◽

Different Dimensions

The present article proposes a measure of correlation for multiqubit mixed states. The measure is defined recursively, accumulating the correlation of the subspaces, making it simple to calculate without the use of regression. Unlike usual measures, the proposed measure is continuous additive and reflects the dimensionality of the state space, allowing to compare states with different dimensions. Examples show that the measure can signal critical points (CPs) in the analysis of Quantum Phase Transitions (QPTs) in Heisenberg models.

Download Full-text

QUANTUM PHASE TRANSITIONS IN MESOSCOPIC SYSTEMS

International Journal of Modern Physics B ◽

10.1142/s0217979206035187 ◽

2006 ◽

Vol 20 (19) ◽

pp. 2687-2694 ◽

Cited By ~ 4

Author(s):

F. IACHELLO

Keyword(s):

Phase Transitions ◽

Critical Points ◽

Quantum Phase Transitions ◽

Quantum Phase ◽

Mesoscopic Systems ◽

Spectral Signatures

Shape phase transitions in nuclei, an example of quantum phase transitions in mesoscopic systems, are briefly reviewed. Spectral signatures of critical points in finite quantal systems are discussed and experimental examples are shown.

Download Full-text

The Structure of Liquid Copper-Magnesium Alloys

Zeitschrift für Naturforschung A ◽

10.1515/zna-1973-0225 ◽

1973 ◽

Vol 28 (2) ◽

pp. 297-304

Author(s):

W.E. Lukens ◽

C.N.J. Wagner

Keyword(s):

Liquid Copper ◽

Distribution Functions ◽

X Rays ◽

Negative Deviation ◽

Transmission Technique ◽

Straight Line ◽

Structure Factors ◽

Partial Interference ◽

The Fourier Transform ◽

Partial Distribution

X-rays (MoKα) have been used as a radiation probe to evaluate the interference functions I(K) (or structure factors) of liquid Cu, Mg and Cu-Mg alloys with 49, 66, and 86 at. % Mg at temperatures about 50°C above the liquidus. Employing the transmission technique, I(K) has been determined in the range of K = 4π sin Θ/λ between 0.8 A-1 and 12.5 A-1. All I(K) of the alloys exhibit a premaximum at K = 1.5 A-1.The partial interference functions Iij(K) have been determined, and it was found that the assumption of concentration independence of Iij(K) yielded reduced partial distribution functions Gij(r), the weighted sum of which were only in fair agreement with G(r), the Fourier transform of F(K) = K[I(K)-1].The positions, r, of the first peak in G(r) and the coordination number, η, determined from the radial distribution function 4π r2 ρ(r) = r G(r) + 4πr2 ρo, where ρo is the average atomic density of the alloy, show a negative deviation from a straight line when plotted as a function of concentration, which might be considered as evidence for the existence of short-range order in the liquid. Art. 2288

Download Full-text