A double-sum Kronecker-type identity

We prove a double-sum analog of an identity known to Kronecker and then express it in terms of functions studied by Appell and Kronecker's student Lerch, in so doing we show that the double-sum analog is of mixed mock modular form. We also give related symmetric generalizations.Comment: Major revisions. Identities (1.10) and (1.11) are ne

Linking Phase Transitions and Quantum Entanglement at Arbitrary Temperature

In this work, we establish a general theory of phase transitions and quantum entanglement in the equilibrium state at arbitrary temperatures. First, we derived a set of universal functional relations between the matrix elements of two-body reduced density matrix of the canonical density matrix and the Helmholtz free energy of the equilibrium state, which implies that the Helmholtz free energy and its derivatives are directly related to entanglement measures because any entanglement measures are defined as a function of the reduced density matrix. Then we show that the first order phase transitions are signaled by the matrix elements of reduced density matrix while the second order phase transitions are witnessed by the first derivatives of the reduced density matrix elements. Near second order phase transition point, we show that the first derivative of the reduced density matrix elements present universal scaling behaviors. Finally we establish a theorem which connects the phase transitions and entanglement at arbitrary temperatures. Our general results are demonstrated in an experimentally relevant many-body spin model.Comment: 8 pages,2 figure

Evolution in Asynchronous Cellular Automata

Final Accepted Versio

Topological Order in the Phase Diagram for High-Temperature Superconductors with Point Defects

Applying a Lindemann-like criterion obtained previously by Kierfeld, Nattermann and Hwa [Phys. Rev. B 55, 626 (1997)], we estimate the magnetic field and temperature for a high-$T_c$ superconductor, at which a topologically ordered vortex glass phase becomes unstable with respect to a disorder-induced formation of dislocations. The employed criterion is shown to be equivalent to a conventional phenomenological Lindemann criterion including the values for the numerical factors, i.e., for the Lindemann-number. The positional correlation length of the topologically ordered vortex glass is calculated.Comment: 8 pages, REVTEX 3.0, uses epsf, 1 eps-figure, major changes: Lindemann-like criterion is applied to YBCO, the electromagnetic coupling and the possibility of strong pinning are considered, version accepted for publication in Physica

Personal Marketing Plan and Its Influence on Employability

The objective of this paper is to review and analyze the main components of a personal marketing plan Engineers in Business Management Graduates ITLAC for better employability in the labor market. The analys is assumes that currently personal marketing has become an in dispensable tool to achieve professional and personal success, enabling graduates of this professional profile make selling your image to achieve their objectives and goals. The method used is descriptive analytic from a literature review. Finallya marketing personal marketing plan is proposed.Keywords. Graduates, Employability, Personal image, The labor market and personal marketing plan.JEL. I21, J44, L84, M31

Effects of an oscillating field on pattern formation in a ferromagnetic thin film: Analysis of patterns traveling at a low velocity

Magnetic domain patterns under an oscillating field is studied theoretically by using a simple Ising-like model. We propose two ways to investigate the effects of the oscillating field. The first one leads to a model in which rapidly oscillating terms are averaged out, and the model can explain the existence of the maximum amplitude of the field for the appearance of patterns. The second one leads to a model that includes the delay of the response to the field, and the model suggests the existence of a traveling pattern which moves very slowly compared with the time scale of the driving field.Comment: 9 pages, 3 figure