Pion correlation from Skyrmion-AntiSkyrmion annihilation

We study two pion correlations from Skyrmion and antiSkyrmion collision, using the product ansatz and an approximate random grooming method for nucleon projection. The spatial-isospin coupling inherent in the Skyrme model, along with empirical averages, leads to correlations not only among pions of like charges but also among unlike charge types.Comment: uuencoded files of REVTeX and postscript, 18 pages including 2 figures, submitted to Phys.Rev.

Quantum critical point in heavy fermions

The concept that heavy fermions are close to a quantum critical point and that this proximity determines their physical behavior, has opened new perspectives in the study of these systems. It has provided a new paradigm for understanding and probing the properties of these strongly correlated materials. Scaling ideas were important to establish this approach. We give below a brief and personal account of the genesis of some of these ideas 15 years ago, their implications and the future prospects for this exciting field.Comment: 7 pages, 3 figures, to be published in Brazilian Journal of Physic

Smith e Keynes sobre as unidades de salário [Smith and Keynes on wage units]

The paper analyses Adam Smith's labour commanded value theory and proceeds with a comparison between this theory and Keynes' wage units approach, demonstrating that both authors were mainly concerned with a nominal anchor to the measure of value. This similarity in both theories is observed in the economic literature in several occasions However, there are no detailed analyses of the elements that originate the differences between those authors as for the monetary theory and which are in a way or another associated to the use of nominal wages as an anchor for the measurement of value.Keynes, Smith, wage units

SKEWNESS IN INDIVIDUAL STOCKS AT DIFFERENT FREQUENCIES

This paper examines the (a)symmetry of twenty-four individual stock returns at different frequencies: daily, weekly and monthly. While some asymmetries are observed in daily returns, they disappear almost completely at lower frequencies. The explanation for this fact lies in the convergence to normality that takes place when frequency decreases. These features allow one to question several financial models; in particular, they question the preference for positive skewness as a factor for investments in stock markets. Este artículo examina la (a)simetría de las rentabilidades de veinticuatro valores individuales para diferentes frecuencias: diaria, semanal y mensual. Aunque se observan algunas asimetrías en las rentabilidades diarias, éstas desaparecen casi completamente en frecuencias menores. La explicación a este fenómeno reside en la convergencia a la normalidad que se produce al disminuir la frecuencia. Estos hechos cuestionan varios modelos financieros; en concreto cuestionan la preferencia por la asimetría positiva como un factor de inversión en los mercados de acciones.Diversificación, simetría. Diversification, skewness, symmetry.

MACROECONOMIC SYNCHRONIZATION BETWEEN G3 COUNTRIES

This paper studies the existence of a world business cycle by examining quarterly and annual comovements in production, prices, and interest rates in the three main world economies: Germany, Japan and the U.S. In accordance with earlier studies, contemporaneous relationships clearly dominate short-term dynamics. The evidence indicates that, in the last four decades, these comovements are clearly significant in all the variables, with the possible exception of short-term interest rates, and they are stronger for long-term interest rates; nevertheless, they are rather unstable over time. Este artículo estudia la existencia de un ciclo económico mundial mediante elexamen de movimientos comunes en la producción, los precios y los tipos de interés enlas tres mayores economías mundiales: Alemania, Japón y los Estados Unidos. Deacuerdo con estudios anteriores, las relaciones contemporáneas dominan claramente alas relaciones dinámicas a corto plazo. La evidencia indica que, en las últimas cuatrodécadas, estos movimientos comunes son claramente significativos para todas lasvariables, con la posible excepción de los tipos de interés a corto plazo, y de mayorintensidad para los tipos de interés a largo plazo; sin embargo, son bastante inestables alo largo del tiempo.ciclo económico mundial, movimiento común, sincronización. comovement; synchronization; world business cycle.

HAPPINESS, SATISFACTION AND SOCIOECONOMIC CONDITIONS: SOME INTERNATIONAL EVIDENCE

This paper examines the relationships between socioeconomic conditions and happiness or satisfaction of individuals in 15 countries. In agreement with earlier studies, age, health and marital status are strongly associated with happiness and satisfaction. In seeming contrast with other studies, unemployment does not appear to be associated with happiness, although it is clearly associated with satisfaction. Income is also strongly associated with satisfaction, but its association with happiness is weaker. These results point to happiness and satisfaction as two distinct spheres of well-being. While the first would be relatively independent of economic factors, the second would be strongly dependent. Este trabajo examina las relaciones entre las condiciones socioeconómicas y la felicidad o la satisfacción de individuos de 15 países. De acuerdo con estudios anteriores, la edad, la salud y el estado civil están fuertemente asociadas con la felicidad y la satisfacción. En contraste aparente con otros estudios, el desempleo no parece estar asociado con la felicidad, aunque lo está claramente con la satisfacción. La renta también está fuertemente asociada con la satisfacción, pero su asociación con la felicidad es más débil. Estos resultados sugieren que la felicidad y la satisfacción constituyen dos ámbitos distintos del bienestar. Mientras que el primero sería relativamente independiente de factores económicos, el segundo dependería fuertemente de estos factores.felicidad, satisfacción. happiness; satisfaction

Black brane steady states

We follow the evolution of an asymptotically AdS black brane with a fixed temperature gradient at spatial infinity until a steady state is formed. The resulting energy density and energy flux of the steady state in the boundary theory are compared to a conjecture on the behavior of steady states in conformal field theories. Very good agreement is found.Comment: 8 pages, 3 figures. References added, typos correcte

ECONOMIC COMOVEMENTS IN EUROPEAN COUNTRIES

This paper examines the existence of common movements in production, prices and interest rates in three countries: France, Germany and the United Kingdom. To analyse this issue, the usual approach of studying cross-correlations is extended. Though these European countries are closely linked to each other, the results obtained vary substantially over time, with the economic variables and in the countries under consideration. Este trabajo examina la existencia de movimientos comunes en la producción, en los precios y en los tipos de interés en tres países: Francia, Alemania y el Reino Unido. Para analizar este tema, se extiende el enfoque habitual del estudio de las correlaciones cruzadas. A pesar de que estos países europeos están estrechamente relacionados, los resultados varían apreciablemente a lo largo del tiempo, con las variables económicas y en los países en consideración.Ciclo económico; comovimientos. Business cycle; comovements

Coupled fermion-kink system in Jackiw-Rebbi model

In this paper we study Jackiw-Rebbi model, in which a massless fermion is coupled to the kink of $\lambda \phi^4$ theory through a Yukawa interaction. In the original Jackiw-Rebbi model the soliton is prescribed. However, we are interested in the back-reaction of the fermion on the soliton besides the effect of the soliton on the fermion. Also, as a particular example, we consider a minimal supersymmetric kink model, $\mathcal{N}=1$, in ($1+1$) dimensions. In this case, the bosonic self-coupling, $\lambda$, and the Yukawa coupling between fermion and soliton, $g$, have specific relation, $g=\sqrt{\lambda/2}$. As the set of coupled equations of motion of the system is not analytically solvable, we use a numerical method to solve it self-consistently. We obtain the bound energy spectrum, bound states of the system and the corresponding shape of the soliton using a relaxation method, except for the zero mode fermionic state and threshold energies which are analytically solvable. With the aid of these results we are able to show how the soliton is affected in general and supersymmetric cases. The results we obtain are consistent with the ones in the literature, considering the soliton as background.Comment: 14 pages, 9 figure