222 research outputs found
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 dĂa 20 de diciembre de 2000 en Donostia titulado "El Sistema de Concierto y la UniĂłn Europea" y enmarcado dentro de las Jornadas de Estudio sobre «Concierto y Convenio EconĂłmico
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 , 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
in one case) and high statistics are used. We fix and explore
specially a region of -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 ,
while for smaller values of 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 sĂ mismo en Xavier Zubiri
El «saber sobre sĂ mismo» es una cuestiĂłn controvertida desde los orĂgenes de la filosofĂa occidental. Fue consigna de carácter filosĂłfico en SĂłcrates. Posteriormente, su tratamiento es diverso en S. AgustĂn, en Descartes, en el idealismo, hasta la actualidad. En este trabajo pensamos en lo que ha dicho Xavier Zubiri del saber inmediato sobre sĂ mismo. En la intelecciĂłn sentiente, en su primer modo o primordial (y con un ulterior desarrollo en los modos de logos y razĂłn), uno mismo se presenta a sĂ mismo como «mĂ», «realidad mĂa», 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 «mĂ». En sentimiento afectante, el enigma de la realidad del «mĂ» 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»
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