The asymmetric ABAB matrix model

In this letter, it is pointed out that the two matrix model defined by the action S=(1/2)(tr A^2+tr B^2)-(alpha_A/4) tr A^4-(alpha_B/4) tr B^4-(beta/2) tr(AB)^2 can be solved in the large N limit using a generalization of the solution of Kazakov and Zinn-Justin (who considered the symmetric case alpha_A=alpha_B). This model could have useful applications to 3D Lorentzian gravity.Comment: 7 pages, 1 figur

Universality of correlation functions of hermitian random matrices in an external field

The behavior of correlation functions is studied in a class of matrix models characterized by a measure $\exp(-S)$ containing a potential term and an external source term: S=N\tr(V(M)-MA). In the large $N$ limit, the short-distance behavior is found to be identical to the one obtained in previously studied matrix models, thus extending the universality of the level-spacing distribution. The calculation of correlation functions involves (finite $N$) determinant formulae, reducing the problem to the large $N$ asymptotic analysis of a single kernel $K$. This is performed by an appropriate matrix integral formulation of $K$. Multi-matrix generalizations of these results are discussed.Comment: 29 pages, Te

Labor Solidarity In the New World Order: The UMWA Program in Colombia

[Excerpt] Globalization of capital is not a new problem, but it is a persistent and growing one. Capital\u27s ability to search the world over for the cheapest labor enables corporations to maintain oppressive working conditions and leads to downward pressures on living and working standards throughout the world. U.S. coal miners and their union, the United Mine Workers of America (UMWA), realized many years ago that waging struggles in this country was not enough to successfully deal with the reality of job and capital flight to repressive, low-wage countries. Just using the old methods won\u27t work anymore. We must also join forces across industry lines and national boundaries if we want to be successful. And we must come up with new and creative means to confront corporate power. But it often takes years of developing relationships and working together to develop the close bonds and trust that are necessary for effective solidarity. The UMWA has been forging these bonds with the Colombian mine workers\u27 union, Sindicato de los Trabajadores del Intercor (SlNTERCOR), since 1988. Forging alliances is only half the work of effective international solidarity. Unions also need comprehensive strategies that attack corporations from every possible angle. Only by employing an arsenal of different approaches can we ever hope to confront a multinational corporation as huge and powerful as Exxon

Precise determination of critical exponents and equation of state by field theory methods

Renormalization group, and in particular its Quantum Field Theory implementation has provided us with essential tools for the description of the phase transitions and critical phenomena beyond mean field theory. We therefore review the methods, based on renormalized phi^4_3 quantum field theory and renormalization group, which have led to a precise determination of critical exponents of the N-vector model (R. Guida and J. Zinn-Justin, J. Phys. A31 (1998) 8103. cond-mat/9803240). and of the equation of state of the 3D Ising model (R. Guida and J. Zinn-Justin, Nucl. Phys. B489 [FS] (1997) 626, hep-th/9610223.). These results are among the most precise available probing field theory in a non-perturbative regime.Comment: 23 pages, tex, private macros, one figur

A MegaCam Survey of Outer Halo Satellites. VII. A Single S\'ersic Index v/s Effective Radius Relation for Milky Way Outer Halo Satellites

In this work we use structural properties of Milky Way's outer halo ($R_G > 25\,\mathrm{kpc}$) satellites (dwarf spheroidal galaxies, ultra-faint dwarf galaxies and globular clusters) derived from deep, wide-field and homogeneous data, to present evidence of a correlation in the S\'ersic index v/s effective radius plane followed by a large fraction of outer halo globular clusters and satellite dwarf galaxies. We show that this correlation can be entirely reproduced by fitting empirical relations in the central surface brightness v/s absolute magnitude and S\'ersic index v/s absolute magnitude parameter spaces, and by assuming the existence of two types of outer halo globular clusters: one of high surface brightness (HSB group), with properties similar to inner halo clusters; and another of low surface brightness (LSB group), which share characteristics with dwarf spheroidal and ultra-faint dwarf galaxies. Given the similarities of LSB clusters with dwarf spheroidal and ultra-faint dwarf galaxies, we discuss the possibility that outer halo clusters also originated inside dark matter halos and that tidal forces from different galaxy host's potentials are responsible for the different properties between HSB and LSB clusters.Comment: 20 pages, 9 figures, 3 table

The D=1 Matrix Model and the Renormalization Group

We compute the critical exponents of $d = 1$ string theory to leading order, using the renormalization group approach recently suggested by Br\'{e}zin and Zinn-Justin.Comment: 8 pages, Latex, CERN-TH-6546/9

Critical Exponents of the N-vector model

Recently the series for two RG functions (corresponding to the anomalous dimensions of the fields phi and phi^2) of the 3D phi^4 field theory have been extended to next order (seven loops) by Murray and Nickel. We examine here the influence of these additional terms on the estimates of critical exponents of the N-vector model, using some new ideas in the context of the Borel summation techniques. The estimates have slightly changed, but remain within errors of the previous evaluation. Exponents like eta (related to the field anomalous dimension), which were poorly determined in the previous evaluation of Le Guillou--Zinn-Justin, have seen their apparent errors significantly decrease. More importantly, perhaps, summation errors are better determined. The change in exponents affects the recently determined ratios of amplitudes and we report the corresponding new values. Finally, because an error has been discovered in the last order of the published epsilon=4-d expansions (order epsilon^5), we have also reanalyzed the determination of exponents from the epsilon-expansion. The conclusion is that the general agreement between epsilon-expansion and 3D series has improved with respect to Le Guillou--Zinn-Justin.Comment: TeX Files, 27 pages +2 figures; Some values are changed; references update