8,630 research outputs found
Universal properties of the U(1) current at deconfined quantum critical points: comparison with predictions from gauge/gravity duality
The deconfined quantum critical point of a two-dimensional SU(N)
antiferromagnet is governed by an Abelian Higgs model in spacetime
dimensions featuring complex scalar fields. In this context, we derive for
an exact formula for the central charge of the U(1) current in
terms of the gauge coupling at quantum criticality and compare it with the
corresponding result obtained using gauge-gravity duality. There is a
remarkable similarity precisely for . In this case the amplitude of the
current correlation function has the same form as predicted by the
gauge-gravity duality. We also compare finite temperature results for the
charge susceptibility in the large limit with the result predicted by the
gauge-gravity duality. Our results suggest that condensed matter systems at
quantum criticality may provide interesting quantitative tests of the
gauge-gravity duality even in absence of supersymmetry.Comment: 4.5 pages, 1 figure; v2: accepted in PRD, text restructured to make
presentation/discussion clearer, references adde
Ground State of the Hydrogen Atom via Dirac Equation in a Minimal Length Scenario
In this work we calculate the correction to the ground state energy of the
hydrogen atom due to contributions arising from the presence of a minimal
length. The minimal length scenario is introduced by means of modifying the
Dirac equation through a deformed Heisenberg algebra (kempf algebra). With the
introduction of the Coulomb potential in the new Dirac energy operator, we
calculate the energy shift of the ground state of the hydrogen atom in first
order of the parameter related to the minimal length via perturbation theory.Comment: 11 page
Phase structure of Abelian Chern-Simons gauge theories
We study the effect of a Chern-Simons (CS) term in the phase structure of two
different Abelian gauge theories. For the compact Maxwell-Chern-Simons theory,
we obtain that for values of the CS coupling with ,
the theory is equivalent to a gas of closed loops with contact interaction,
exhibiting a phase transition in the universality class. We also employ
Monte Carlo simulations to study the noncompact U(1) Abelian Higgs model with a
CS term. Finite size scaling of the third moment of the action yields critical
exponents and that vary continuously with the strength of the CS
term, and a comparison with available analytical results is made.Comment: RevTex4, 4 pages, 1 figure; v3: improvements and corrections made in
the first part of the paper; references added. To be published in Europhysics
Letter
Erythrocyte filtrability and oxyhemoglobin dissociation in hypertensive patients
Twenty one patients with essential hypertension were studied.
A significant decrease (p < 0.05) of hemoglobin oxygen affinity and a marked reduction (p < 0.001) of erythrocyte filtrability was detected. The results suggest an abnormality of the erythrocyte deformability in the microcirculation of the hypertensive patients, which implies a shift to the right of the oxyhemoglobin dissociation curve as a means of adaptation to the relative tissue hypoxia.This study was supported by a grant from INIC (MbL2)
Compact U(1) gauge theories in 2+1 dimensions and the physics of low dimensional insulating materials
Compact abelian gauge theories in dimensions arise often as an
effective field-theoretic description of models of quantum insulators. In this
paper we review some recent results about the compact abelian Higgs model in
in that context.Comment: 5 pages, 3 figures; based on talk by F.S. Nogueira in the Aachen
HEP2003 conferenc
Valoración de la condición fÃsica en niños de 11-12 años con distinto nivel socio-económico
Este estudio comparativo consiste en la evaluación de un grupo concreto de niños de distintos niveles socio-económicos a los cuales se les han tomado las medidas antropométricas de peso y talla, además de una serie de pruebas fÃsicas consistentes en el salto a pies juntos horizontal, lanzamiento de balón medicinal, 50 mts lisos y flexibilidad. Conclusiones: No existen diferencias significativas entre los dos colegios exceptuando la talla al 90 % entre los dos colegios
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