Analysis of Shot Noise at Finite Temperatures in Fractional Quantum Hall Edge States

We investigate shot noise at {\it finite temperatures} induced by the quasi-particle tunneling between fractional quantum Hall (FQH) edge states. The resulting Fano factor has the peak structure at a certain bias voltage. Such a structure indicates that quasi-particles are weakly {\it glued} due to thermal fluctuation. We show that the effect makes it possible to probe the difference of statistics between $\nu=1/5,{}2/5$ FQH states where quasi-particles have the same unit charge.Finally we propose a way to indirectly obtain statistical angle in hierarchical FQH states.Comment: 5 pages, 3 figure

Los sistemas de calefacción doméstica de la villa romana La Olmeda, Palencia

The use of hypocausta in non-thermal rooms has been little studied, in fact, in almost all occasions it is associated with the domestic balnea of the villas or the public baths. But it is also frequent in the Roman villas the existence of hypocausta that provide thermal conditioning to dependencies not necessarily related to the baths of the villa. In La Olmeda some of them are indeed part of the thermal installation of the bath circuit, but most of those that have been discovered constitute only a domestic heating system, much needed, on the other hand, in these lands of long and cold winters. The objective of this article is the study of them, its description and possible evolution in Roman times, the planimetry of how they could be constituted and an approximation to its functioning. From the analysis of the obtained data it has been concluded that the characteristics and the constructive systems of the hypocausta are related to the moment of its conception depending if it was a new implantation or some of the reforms due to the own evolution of The Roman villa.El uso de hypocausta en estancias de uso no termal ha sido poco estudiado, de hecho, en casi todas las ocasiones se asocia al balnea doméstico de las villas o a las termas públicas. Pero también es frecuente en las villas romanas la existencia de hypocausta que proporcionan acondicionamiento térmico a dependencias no necesariamente relacionada con los baños de la villa. En La Olmeda algunos de ellos efectivamente forman parte de la instalación termal del circuito de baños, pero la mayor parte de los que se han descubierto constituyen únicamente un sistema calefactor doméstico, muy necesario, por otra parte, en estas tierras de inviernos largos y fríos. El objetivo de este artículo es el estudio de los mismos, su descripción y posible evolución en época romana, la planimetría de cómo pudieron estar constituidos y una aproximación a su funcionamiento. Del análisis de los datos obtenidos se ha llegado a la conclusión de que las características y los sistemas constructivos de los hypocausta están en relación con el momento de su concepción dependiendo de si se trataba de una nueva implantación o de alguna de las reformas debidas a la propia evolución de la villa romana

Correlator of Fundamental and Anti-symmetric Wilson Loops in AdS/CFT Correspondence

We study the two circular Wilson loop correlator in which one is of anti-symmetric representation, while the other is of fundamental representation in 4-dimensional ${\cal N}=4$ super Yang-Mills theory. This correlator has a good AdS dual, which is a system of a D5-brane and a fundamental string. We calculated the on-shell action of the string, and clarified the Gross-Ooguri transition in this correlator. Some limiting cases are also examined.Comment: 22 pages, 5 figures, v2: typos corrected, v3: final version in JHE

Page charge of D-branes and its behavior in topologically nontrivial B-fields

The RR Page charges for the D(2p+1)-branes with B-field in type IIB supergravity are constructed consistently from brane source currents. The resulting Page charges are B-independent in the nontrivial and intricate way. It is found that in topologically trivial B-field the Page charge is conserved, but in the topologically nontrivial B-field it is no longer to be conserved, instead there is a jump between two Page charges defined in each patch, and we interpret this jump as Hanany-Witten effect.Comment: 25 pages, 4 figures, typos corrected and reference adde

Hydrogen Production by Formic Acid Decomposition over Ca Promoted Ni/SiO2 Catalysts: Effect of the Calcium Content

Formic acid, a major product of biomass processing, is regarded as a potential liquid carrier for hydrogen storage and delivery. The catalytic dehydrogenation of FA to generate hydrogen using heterogeneous catalysts is of great interest. Ni based catalysts supported on silica were synthesized by incipient wet impregnation. The eect of doping with an alkaline earth metal (calcium) wasstudied, and the solids were tested in the formic acid decomposition reaction to produce hydrogen.The catalysts were characterized by X-ray diraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and programmed temperature surface reaction (TPSR).The catalyst doped with 19.3 wt.% of Ca showed 100% conversion of formic acid at 160 C, with a 92% of selectivity to hydrogen. In addition, all the tested materials were promising for their application, since they showed catalytic behaviors (conversion and selectivity to hydrogen) comparable to thoseof noble metals reported in the literature.Fil: Faroldi, Betina María Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Paviotti, María Aneley. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Camino-Manjarrés, M.. Universidad de Salamanca; EspañaFil: González-Carrazán, S.. Universidad de Salamanca; EspañaFil: López-Olmos, C.. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica; EspañaFil: Rodríguez-Ramos, I.. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica; Españ

A local-global principle for linear dependence of noncommutative polynomials

A set of polynomials in noncommuting variables is called locally linearly dependent if their evaluations at tuples of matrices are always linearly dependent. By a theorem of Camino, Helton, Skelton and Ye, a finite locally linearly dependent set of polynomials is linearly dependent. In this short note an alternative proof based on the theory of polynomial identities is given. The method of the proof yields generalizations to directional local linear dependence and evaluations in general algebras over fields of arbitrary characteristic. A main feature of the proof is that it makes it possible to deduce bounds on the size of the matrices where the (directional) local linear dependence needs to be tested in order to establish linear dependence.Comment: 8 page

Supersymmetric D-branes in the D1-D5 background

We construct supersymmetric D-brane probe solutions in the background of the 2-charge D1-D5 system on M, where M is either K3 or T^4. We focus on `near-horizon bound states' that preserve supersymmetries of the near-horizon AdS_3 x S^3 x M geometry and are static with respect to the global time coordinate. We find a variety of half-BPS solutions that span an AdS_2 subspace in AdS_3, carry worldvolume flux and can wrap an S^2 within S^3 and/or supersymmetric cycles in M.Comment: Latex, 24 pages. v2: references added, modified Discussion, published versio

Adding flavor to the gravity dual of non-commutative gauge theories

We study the addition of flavor degrees of freedom to the supergravity dual of the non-commutative deformation of the maximally supersymmetric gauge theories. By considering D7 flavor branes in the probe approximation and studying their fluctuations we extract the spectrum of scalar and vector mesons as a function of the non-commutativity. We find that the spectrum for very large non-commutative parameter is equal to the one in the commutative theory, while for some intermediate values of the non-commutativity some of the modes disappear from the discrete spectrum. We also study the semiclassical dynamics of rotating open strings attached to the D7-brane, which correspond to mesons with large spin. Under the effect of the non-commutativity the open strings get tilted. However, at small(large) distances they display the same Regge-like (Coulombic) behaviour as in the commutative theory. We also consider the addition of D5-flavor branes to the non-commutative deformation of the N=1 supersymmetric Maldacena-Nunez background.Comment: 50 pages, 9 figures, LaTeX; v2: minor improvements, references added; v3: typos correcte

On gravitational description of Wilson lines

We study solutions of Type IIB supergravity, which describe the geometries dual to supersymmetric Wilson lines in N=4 super-Yang-Mills. We show that the solutions are uniquely specified by one function which satisfies a Laplace equation in two dimensions. We show that if this function obeys a certain Dirichlet boundary condition, the corresponding geometry is regular, and we find a simple interpretation of this boundary condition in terms of D3 and D5 branes which are dissolved in the geometry. While all our metrics have AdS_5 x S^5 asymptotics, they generically have nontrivial topologies, which can be uniquely specified by a set of non-contractible three- and five-spheres.Comment: 46 page