Search results for " Order"
showing 10 items of 827 documents
Metáforas y parábolas. Notas para una estética tangencial en J.D. García Bacca
2019
La belleza ha sido, desde tiempo de los griegos, el tormento de los filósofos; conformarse tal idea apresándola bajo una definición a la que se niega ha ocupado, siempre en vano, la tarea de no pocos pensadores hasta la actualidad. La hermosura no deja racionalizarse y hace así de la razón una sinrazón; ni es cognoscible, ni posee estructura lógica. Es por ello que a través de la percepción estética aprehendemos lo que en sí no es perceptible; es la experiencia de apertura de una interioridad que hasta el momento había permanecido oculta a los ojos de lo cotidiano y adquiere ahora un rango de primer orden.
Self-duality and periodicity at finite filling fraction
2005
We investigate a model of interacting charged particles in two space dimensions, with manifest invariance under duality and periodicity under flux attachment. This model, introduced by Fradkin and Kivelson (1996 Nucl. Phys. B 474 543), shares many qualitative features of real quantum Hall systems. We extend this model to the case of finite filling fraction, i.e., to physical systems without particle–hole symmetry and without time-reversal invariance. We derive the transformation laws for the the average currents and prove that they have an SL (2, Z) symmetry. We can then calculate the filling factors at the modular fixed points and further explore the topological order of the model by const…
Diffusive behavior and the modeling of characteristic times in limit order executions
2007
We present an empirical study of the first passage time (FPT) of order book prices needed to observe a prescribed price change Delta, the time to fill (TTF) for executed limit orders and the time to cancel (TTC) for canceled ones in a double auction market. We find that the distribution of all three quantities decays asymptotically as a power law, but that of FPT has significantly fatter tails than that of TTF. Thus a simple first passage time model cannot account for the observed TTF of limit orders. We propose that the origin of this difference is the presence of cancellations. We outline a simple model, which assumes that prices are characterized by the empirically observed distribution …
How does the market react to your order flow?
2012
We present an empirical study of the intertwined behaviour of members in a financial market. Exploiting a database where the broker that initiates an order book event can be identified, we decompose the correlation and response functions into contributions coming from different market participants and study how their behaviour is interconnected. We find evidence that (1) brokers are very heterogeneous in liquidity provision -- some are consistently liquidity providers while others are consistently liquidity takers. (2) The behaviour of brokers is strongly conditioned on the actions of {\it other} brokers. In contrast brokers are only weakly influenced by the impact of their own previous ord…
Konishi form factor at three loops in N=4 supersymmetric Yang-Mills theory
2017
We present the first results on the third order corrections to on-shell form factor (FF) of the Konishi operator in $\mathcal{N}=4$ supersymmetric Yang-Mills theory using Feynman diagrammatic approach in modified dimensional reduction ($\overline{DR}$) scheme. We show that it satisfies the KG equation in $\overline{DR}$ scheme while the result obtained in four dimensional helicity (FDH) scheme needs to be suitably modified not only to satisfy the KG equation but also to get the correct ultraviolet (UV) anomalous dimensions. We find that the cusp, soft and collinear anomalous dimensions obtained to third order are same as those of the FF of the half-BPS operator confirming the universality o…
Absolute frequency measurement of rubidium 5S-7S two-photon transitions.
2013
We report the absolute frequency measurements of rubidium 5S-7S two-photon transitions with a cw laser digitally locked to an atomic transition and referenced to an optical frequency comb. The narrow, two-photon transition, 5S-7S (760 nm) insensitive to first order in a magnetic field, is a promising candidate for frequency reference. The performed tests yield the transition frequency with accuracy better than reported previously.
Classical chaos and harmonic generation in laser driven nanorings
2016
A quantum ring driven by an intense laser field emits light in the form of high-harmonic radiation resulting from the strong acceleration experienced by the active electrons forced to move on a curved trajectory. The spectrum of the emitted light is rich and strongly dependent on the parameters of the problem. In order to investigate the physical origin of such variability, we focus on the seemingly simple problem of a laser-driven charge constrained to a ring from a classical standpoint. As it turns out, the dynamics of such a classical electron is governed by a nonlinear equation which results into a chaotic motion - by nature depending on the initial conditions in an unpredictable way. O…
The B0.5 IVe CoRoT target HD 49330. II. Spectroscopic ground-based observations
2009
International audience; Context: We present spectroscopic ground-based observations of the early Be star HD 49330 obtained simultaneously with the CoRoT-LRA1 run just before the burst observed in the CoRoT data. Aims: Ground-based spectroscopic observations of the early Be star HD 49330 obtained during the precursor phase and just before the start of an outburst allow us to disantangle stellar and circumstellar contributions and identify modes of stellar pulsations in this rapidly rotating star. Methods: Time series analysis (TSA) is performed on photospheric line profiles of He I and Si III by means of the least squares method. Results: We find two main frequencies f1 = 11.86 c d-1 and f2 …
Topological Insulators in Ternary Compounds with a Honeycomb Lattice
2010
One of the most exciting subjects in solid state physics is a single layer of graphite which exhibits a variety of unconventional novel properties. The key feature of its electronic structure are linear dispersive bands which cross in a single point at the Fermi energy. This so-called Dirac cone is closely related to the surface states of the recently discovered topological insulators. The ternary compounds, such as LiAuSe and KHgSb with a honeycomb structure of their Au-Se and Hg-Sb layers feature band inversion very similar to HgTe which is a strong precondition for existence of the topological surface states. In contrast to graphene with two Dirac cones at K and K' points, these material…
Topological insulators in filled skutterudites
2011
We propose new topological insulators in cerium filled skutterudite (FS) compounds based on ab initio calculations. We find that two compounds CeOs4As12 and CeOs4Sb12 are zero gap materials with band inversion between Os-d and Ce-f orbitals, which are thus parent compounds of two and three-dimensional topological insulators just like bulk HgTe. At low temperature, both compounds become topological Kondo insulators, which are Kondo insulators in the bulk, but have robust Dirac surface states on the boundary. This new family of topological insulators has two advantages compared to previous ones. First, they can have good proximity effect with other superconducting FS compounds to realize Maja…