6,468 research outputs found
Multifractal Properties of Aperiodic Ising Model: role of geometric fluctuations
The role of the geometric fluctuations on the multifractal properties of the
local magnetization of aperiodic ferromagnetic Ising models on hierachical
lattices is investigated. The geometric fluctuations are introduced by
generalized Fibonacci sequences. The local magnetization is evaluated via an
exact recurrent procedure encompassing a real space renormalization group
decimation. The symmetries of the local magnetization patterns induced by the
aperiodic couplings is found to be strongly (weakly) different, with respect to
the ones of the corresponding homogeneous systems, when the geometric
fluctuations are relevant (irrelevant) to change the critical properties of the
system. At the criticality, the measure defined by the local magnetization is
found to exhibit a non-trivial F(alpha) spectra being shifted to higher values
of alpha when relevant geometric fluctuations are considered. The critical
exponents are found to be related with some special points of the F(alpha)
function and agree with previous results obtained by the quite distinct
transfer matrix approach.Comment: 10 pages, 7 figures, 3 Tables, 17 reference
Taxa de prenhez de vacas Nelore submetidas a protocolos de IATF no Planalto Boliviano.
Os benefícios da utilização de métodos reprodutivos alternativos como a inseminação artificial (IA) tem proporcionado avanços significativos no melhoramento do rebanho bovino mundial, além de permitir o controle de doenças venéreas e diminuição de custos de reposição. São também algumas das vantagens apontadas na utilização desta tecnologia a redução na frequência de genes recessivos indesejáveis e difusão genética de touros comprovadamente superiores para regiões do mundo onde sua criação não seria possível.bitstream/item/56917/1/CT101-lancado.pdfNa publicação: Juliana Correa Borges
N=2-Maxwell-Chern-Simons model with anomalous magnetic moment coupling via dimensional reduction
An N=1--supersymmetric version of the Cremmer-Scherk-Kalb-Ramond model with
non-minimal coupling to matter is built up both in terms of superfields and in
a component-field formalism. By adopting a dimensional reduction procedure, the
N=2--D=3 counterpart of the model comes out, with two main features: a genuine
(diagonal) Chern-Simons term and an anomalous magnetic moment coupling between
matter and the gauge potential.Comment: 15 pages, Latex; one reference corrected; To be published in the Int.
J. Mod. Phys.
Deconfined quantum criticality driven by Dirac fermions in SU(2) antiferromagnets
Quantum electrodynamics in 2+1 dimensions is an effective gauge theory for
the so called algebraic quantum liquids. A new type of such a liquid, the
algebraic charge liquid, has been proposed recently in the context of
deconfined quantum critical points [R. K. Kaul {\it et al.}, Nature Physics
{\bf 4}, 28 (2008)]. In this context, we show by using the renormalization
group in spacetime dimensions, that a deconfined quantum
critical point occurs in a SU(2) system provided the number of Dirac fermion
species . The calculations are done in a representation where the
Dirac fermions are given by four-component spinors. The critical exponents are
calculated for several values of . In particular, for and
() the anomalous dimension of the N\'eel field is given by
, with a correlation length exponent . These values change
considerably for . For instance, for we find and . We also investigate the effect of chiral
symmetry breaking and analyze the scaling behavior of the chiral holon
susceptibility, .Comment: 13 pages, 3 figures; published versio
- …