Perturbative Ward identities for Yang-Mills field theory stochastically quantized

%'e compute the divergent part of the three-point vertex function of the non-Abelian Yang-Mills gauge field theory within the stochastic quantization approach to the one-loop order. This calculation allows us to find four renormalization constants which, together with the four previously obtained, verify, to the calculated order, some Ward identities

Clausura

Clausura del monográfico celebrado el día 20 de diciembre de 2000 en Donostia titulado "El Sistema de Concierto y la Unión Europea" y enmarcado dentro de las Jornadas de Estudio sobre «Concierto y Convenio Económico

A Proposal of a Renormalization Group Transformation for Lattice Field Theories

We propose a new Real Space Renormalization Group transformation useful for Monte Carlo calculations in theories with global or local symmetries. From relaxation arguments we define the block-spin transformation with two tunable free parameters, adapted to the system's action. Varying them it is possible to place the fixed point very close to the simulation point. We show how the method works in a simple model with global symmetry: the three dimensional XY model.Comment: 26 pages, uuencoded compressed postscript single file, 8 figures include

The Coulomb-Higgs transition of the three-parameter U(1)-Higgs model

We find a first order Coulomb--Higgs phase transition at moderately large values of the coupling $\lambda$, and no evidence for a change of order at any finite value of it.Comment: 3 pages, uuencoded compressed ps file. Contribution to Lattice '9

Study of the Coulomb-Higgs transition in the Abelian Higgs Model

The order of the Coulomb-Higgs transition in the U(1)-Higgs model with unfrozen modulus of the scalar field is studied. Large lattices (up to $24^4$ in one case) and high statistics are used. We fix $\beta =1.15$ and explore specially a region of $\lambda$-values where metastability is observed. We study the thermodynamical limit of several observables, in particular, the latent heat, the specific heat, the decrement of the free energy between the maxima and the central minimum of the two-peaked histogram, the Binder cumulant and the displacement of the critical coupling with the lattice size. The results point towards a second order transition for $\lambda \gtrsim 0.005$, while for smaller values of $\lambda$ the strong metastability growing with the lattice size seems to derive from a first order character.Comment: 10 pages, Latex, epsfig, uuencoded gzipped tar file, 4 figures include

A proposal of a Renormalization Group transformation

We propose a family of renormalization group transformations characterized by free parameters that may be tuned in order to reduce the truncation effects. As a check we test them in the three dimensional XY model. The Schwinger--Dyson equations are used to study the renormalization group flow.Comment: Contribution to Lattice'94. uuencoded postscript fil

Critical exponents and unusual properties of the broken phase in the 3d-RP(2) antiferromagnetic model

We present the results of a Monte Carlo simulation of the antiferromagnetic RP(2) model in three dimensions. With finite-size scaling techniques we accurately measure the critical exponents and compare them with those of O(N) models. We are able to parameterize the corrections-to-scaling. The symmetry properties of the broken phase are also studied.Comment: 4 pages, TeX type, Poster session contribution to "Lattice96" conference, Washington University, StLoui

Stochastic quantization of Yang-Mills field theory: Gauge-fixing parameter dependence and equilibrium limit

We calculate, in the framework of stochastic quantization, the one-loop-divergent part of the gluon self-energy and the triple-gluon vertex of pure Yang Mills field theory, with an arbitrary choice of the stochastic gauge-fixing parameter. This allows us to check that the strong conditions imposed by renormalizability are satisfied up to one-loop order. We compare our results with those corning from the Faddeev Popov theory and discuss the relationship between both approaches in the equilibrium limit

Nature of the spin-glass phase at experimental length scales

We present a massive equilibrium simulation of the three-dimensional Ising spin glass at low temperatures. The Janus special-purpose computer has allowed us to equilibrate, using parallel tempering, L=32 lattices down to T=0.64 Tc. We demonstrate the relevance of equilibrium finite-size simulations to understand experimental non-equilibrium spin glasses in the thermodynamical limit by establishing a time-length dictionary. We conclude that non-equilibrium experiments performed on a time scale of one hour can be matched with equilibrium results on L=110 lattices. A detailed investigation of the probability distribution functions of the spin and link overlap, as well as of their correlation functions, shows that Replica Symmetry Breaking is the appropriate theoretical framework for the physically relevant length scales. Besides, we improve over existing methodologies to ensure equilibration in parallel tempering simulations.Comment: 48 pages, 19 postscript figures, 9 tables. Version accepted for publication in the Journal of Statistical Mechanic

Sobre el saber inmediato de sí mismo en Xavier Zubiri

El «saber sobre sí mismo» es una cuestión controvertida desde los orígenes de la filosofía occidental. Fue consigna de carácter filosófico en Sócrates. Posteriormente, su tratamiento es diverso en S. Agustín, en Descartes, en el idealismo, hasta la actualidad. En este trabajo pensamos en lo que ha dicho Xavier Zubiri del saber inmediato sobre sí mismo. En la intelección sentiente, en su primer modo o primordial (y con un ulterior desarrollo en los modos de logos y razón), uno mismo se presenta a sí mismo como «mí», «realidad mía», o «intimidad». «Realidad psicosomática». Una intimidad «enigmática » en la que resuena la «voz de la conciencia» proveniente del poder de lo real en cuanto tal, fundamento de la realidad personal del «mí». En sentimiento afectante, el enigma de la realidad del «mí» se manifiesta en su «in-quietud» constituyente. Y en voluntad tendente, mi realidad inquieta y guiada por la «voz de la conciencia», ha de adoptar necesariamente alguna «forma de realidad»